[House Hearing, 111 Congress]
[From the U.S. Government Publishing Office]
THE NEXT GENERATION OF
FUSION ENERGY RESEARCH
=======================================================================
HEARING
BEFORE THE
SUBCOMMITTEE ON ENERGY AND
ENVIRONMENT
COMMITTEE ON SCIENCE AND TECHNOLOGY
HOUSE OF REPRESENTATIVES
ONE HUNDRED ELEVENTH CONGRESS
FIRST SESSION
__________
OCTOBER 29, 2009
__________
Serial No. 111-61
__________
Printed for the use of the Committee on Science and Technology
Available via the World Wide Web: http://www.science.house.gov
______
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COMMITTEE ON SCIENCE AND TECHNOLOGY
HON. BART GORDON, Tennessee, Chair
JERRY F. COSTELLO, Illinois RALPH M. HALL, Texas
EDDIE BERNICE JOHNSON, Texas F. JAMES SENSENBRENNER JR.,
LYNN C. WOOLSEY, California Wisconsin
DAVID WU, Oregon LAMAR S. SMITH, Texas
BRIAN BAIRD, Washington DANA ROHRABACHER, California
BRAD MILLER, North Carolina ROSCOE G. BARTLETT, Maryland
DANIEL LIPINSKI, Illinois VERNON J. EHLERS, Michigan
GABRIELLE GIFFORDS, Arizona FRANK D. LUCAS, Oklahoma
DONNA F. EDWARDS, Maryland JUDY BIGGERT, Illinois
MARCIA L. FUDGE, Ohio W. TODD AKIN, Missouri
BEN R. LUJAN, New Mexico RANDY NEUGEBAUER, Texas
PAUL D. TONKO, New York BOB INGLIS, South Carolina
PARKER GRIFFITH, Alabama MICHAEL T. MCCAUL, Texas
STEVEN R. ROTHMAN, New Jersey MARIO DIAZ-BALART, Florida
JIM MATHESON, Utah BRIAN P. BILBRAY, California
LINCOLN DAVIS, Tennessee ADRIAN SMITH, Nebraska
BEN CHANDLER, Kentucky PAUL C. BROUN, Georgia
RUSS CARNAHAN, Missouri PETE OLSON, Texas
BARON P. HILL, Indiana
HARRY E. MITCHELL, Arizona
CHARLES A. WILSON, Ohio
KATHLEEN DAHLKEMPER, Pennsylvania
ALAN GRAYSON, Florida
SUZANNE M. KOSMAS, Florida
GARY C. PETERS, Michigan
VACANCY
------
Subcommittee on Energy and Environment
HON. BRIAN BAIRD, Washington, Chair
JERRY F. COSTELLO, Illinois BOB INGLIS, South Carolina
EDDIE BERNICE JOHNSON, Texas ROSCOE G. BARTLETT, Maryland
LYNN C. WOOLSEY, California VERNON J. EHLERS, Michigan
DANIEL LIPINSKI, Illinois JUDY BIGGERT, Illinois
GABRIELLE GIFFORDS, Arizona W. TODD AKIN, Missouri
DONNA F. EDWARDS, Maryland RANDY NEUGEBAUER, Texas
BEN R. LUJAN, New Mexico MARIO DIAZ-BALART, Florida
PAUL D. TONKO, New York
JIM MATHESON, Utah
LINCOLN DAVIS, Tennessee
BEN CHANDLER, Kentucky
BART GORDON, Tennessee RALPH M. HALL, Texas
CHRIS KING Democratic Staff Director
SHIMERE WILLIAMS Democratic Professional Staff Member
ELAINE PAULIONIS PHELEN Democratic Professional Staff Member
ADAM ROSENBERG Democratic Professional Staff Member
JETTA WONG Democratic Professional Staff Member
ELIZABETH CHAPEL Republican Professional Staff Member
TARA ROTHSCHILD Republican Professional Staff Member
JANE WISE Research Assistant
C O N T E N T S
October 29, 2009
Page
Witness List..................................................... 2
Hearing Charter.................................................. 3
Opening Statements
Statement by Representative Bart Gordon, Chairman, Committee on
Science and Technology, U.S. House of Representatives.......... 10
Statement by Representative Brian Baird, Chairman, Subcommittee
on Energy and Environment, Committee on Science and Technology,
U.S. House of Representatives.................................. 8
Written Statement............................................ 8
Statement by Representative Bob Inglis, Ranking Minority Member,
Subcommittee on Energy and Environment, Committee on Science
and Technology, U.S. House of Representatives.................. 13
Written Statement............................................ 13
Prepared Statement by Representative Jerry F. Costello, Member,
Subcommittee on Energy and Environment, Committee on Science
and Technology, U.S. House of Representatives.................. 9
Prepared Statement by Representative Eddie Bernice Johnson,
Member, Subcommittee on Energy and Environment, Committee on
Science and Technology, U.S. House of Representatives.......... 10
Statement by Representative Lincoln Davis, Member, Subcommittee
on Energy and Environment, Committee on Science and Technology,
U.S. House of Representatives.................................. 11
Statement by Representative Vernon J. Ehlers, Member,
Subcommittee on Energy and Environment, Committee on Science
and Technology, U.S. House of Representatives.................. 9
Statement by Representative Rush D. Holt, State of New Jersey,
12th District.................................................. 11
Witnesses:
Dr. Edmund J. Synakowski, Associate Director for Fusion Energy
Sciences, Office of Science, U.S. Department of Energy
Oral Statement............................................... 13
Written Statement............................................ 15
Biography.................................................... 22
Dr. Stewart C. Prager, Director, Princeton Plasma Physics
Laboratory
Oral Statement............................................... 22
Written Statement............................................ 24
Biography.................................................... 33
Dr. Thomas E. Mason, Director, Oak Ridge National Laboratory
Oral Statement............................................... 33
Written Statement............................................ 35
Biography.................................................... 39
Dr. Riccardo Betti, Professor, Mechanical Engineering & Physics
and Astronomy; Senior Scientist and Assistant Director for
Academic Affairs, Laboratory for Laser Energetics, University
of Rochester
Oral Statement............................................... 39
Written Statement............................................ 41
Biography.................................................... 47
Dr. Raymond J. Fonck, Professor of Engineering Physics,
University of Wisconsin-Madison
Oral Statement............................................... 48
Written Statement............................................ 49
Biography.................................................... 56
Discussion
How Fusion Energy Becomes a Usable Resource.................... 57
Potential Consumer Prices for Fusion Energy.................... 58
Fusion as an Alternative to Other Energy Sources............... 59
Arguments for Promoting Fusion Research........................ 60
National Security and Technical Elements of Plasmas in Reactors 61
Fusion vs. Wind and Solar Energy............................... 64
Electrifying Transportation.................................... 64
Skeptical Arguments............................................ 65
A Federal Agency Home for Inertial Fusion Research............. 67
Fusion as an Unacceptable Substitute for Conservation.......... 68
Closing........................................................ 69
Appendix 1: Answers to Post-Hearing Quetions
Dr. Edmund J. Synakowski, Associate Director for Fusion Energy
Sciences, Office of Science, U.S. Department of Energy......... 72
Appendix 2: Additional Material for the Record
Additional Testimony by Dr. Stewart C. Prager, Director,
Princeton Plasma Physics Laboratory............................ 76
THE NEXT GENERATION OF FUSION ENERGY RESEARCH
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THURSDAY, OCTOBER 29, 2009
House of Representatives,
Subcommittee on Energy and Environment,
Committee on Science and Technology,
Washington, DC.
The Subcommittee met, pursuant to call, at 10:03 a.m., in
Room 2318 of the Rayburn House Office Building, Hon. Brian
Baird [Chairman of the Subcommittee] presiding.
hearing charter
SUBCOMMITTEE ON ENERGY AND ENVIRONMENT
COMMITTEE ON SCIENCE AND TECHNOLOGY
U.S. HOUSE OF REPRESENTATIVES
The Next Generation of
Fusion Energy Research
thursday, october 29, 2009
10:00 a.m.-12:00 p.m.
2318 rayburn house office building
Purpose
On Thursday, October 29, 2009 the House Committee on Science and
Technology, Subcommittee on Energy and Environment will hold a hearing
entitled ``The Next Generation of Fusion Energy Research.''
The Subcommittee will receive testimony on research activities
conducted by the Department of Energy (DOE) Office of Science's Fusion
Energy Sciences (FES) program, as well as its collaborations with DOE's
National Nuclear Security Administration (NNSA). In addition, the
Subcommittee will examine the status of international partnerships in
fusion energy research.
Witnesses
Dr. Edmund Synakowski is Director of FES. Dr.
Synakowski will testify on DOE's current fusion research
activities and his vision for how the program should evolve
over the next ten years.
Dr. Stewart Prager is Director of the Princeton
Plasma Physics Laboratory (PPPL) in Princeton, NJ and former
Chair of DOE's Fusion Energy Sciences Advisory Committee
(FESAC). Dr. Prager will testify on PPPL's current and future
roles as a leading center of fusion energy research.
Dr. Thom Mason is Director of Oak Ridge National
Laboratory (ORNL) in Oak Ridge, TN. Dr. Mason will describe the
current status of the ITER international fusion project and the
role of ORNL as the headquarters of the U.S. ITER Project
Office.
Dr. Riccardo Betti is an Assistant Director of the
University of Rochester's Laboratory for Laser Energetics in
Rochester, NY and former Chair of the National Academies Plasma
Science Committee. He was also Chair of a 2009 DOE report on
``Advancing the Science of High Energy Density Laboratory
Plasmas.'' Dr. Betti will testify on the status of inertial
fusion energy (IFE) research and his vision for how DOE should
steward IFE over the next ten years.
Dr. Raymond Fonck is a Professor of Engineering
Physics at the University of Wisconsin-Madison and former
Director of FES. He was also Chair of the 2004 National
Academies report ``Burning Plasma: Bringing a Star to Earth.''
Dr. Fonck will testify on his experience as FES Director and
his vision for a viable U.S. fusion program over the next
several decades.
Background
Fusion is the process that powers the sun and the stars, and U.S.
scientists have investigated ways to replicate this process here on
Earth for over 50 years. Research into fusion for military purposes
began in the early 1940s as part of the Manhattan Project, but was not
successful until 1952. Research on creating controlled fusion devices
to meet growing demands for new energy sources began in the 1950s, and
continues to this day. In one type of this reaction, two atoms of
hydrogen combine together, or fuse, to form an atom of helium. In the
process some of the mass of the hydrogen is converted into energy,
following Einstein's formula: E (Energy) = m (mass) times c (the speed
of light) squared. The easiest fusion reaction to artificially recreate
combines deuterium (a ``heavy'' form of hydrogen as it includes both a
proton and a neutron\1\ ) with tritium (made up of a proton and two
neutrons--the heaviest form of hydrogen found in nature) to make helium
and a neutron. Deuterium is plentifully available in ordinary water,
and tritium can be produced by combining a fusion neutron with the
relatively abundant lithium atom. Thus, if its significant remaining
scientific questions and engineering challenges can be overcome, fusion
may have the potential to be a practically inexhaustible source of
energy.
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\1\ See charter for hearing entitled Investigating the Nature of
Matter, Energy, Space, and Time held on October 1st, 2009 for further
explanation of ``protons'' and ``neutrons,'' which are the primary
constituents of an atom's nucleus.
---------------------------------------------------------------------------
All nuclei in atoms are positively charged, so they have a natural
electromagnetic repulsion pushing them apart. This is because, while
opposite charges attract, like charges repel. Thus to induce the fusion
process, hydrogen gas is typically heated to very high temperatures
(100 million degrees or more) to give the atoms sufficient energy to
overcome this repulsion and fuse. In the process the gas becomes
ionized, meaning that atomic nuclei and their electrons have too much
energy to stay bound to each other as neutrally charged atoms. Thus
what is known as a plasma is formed. Plasmas are considered the fourth
state of matter, after solids, liquids, and gases. Plasmas are unique
from normal gases because large portions of them are either unbound
electrons or charged nuclei (ions), so they can be manipulated by
electric and magnetic fields. If a very hot plasma is held together
(i.e., confined) long enough, then the sheer number of fusion reactions
may produce more energy than what's required to heat the gas,
generating excess energy that can be used for other applications. The
sun and stars do this with gravity. Artificial approaches on Earth
include magnetic confinement, in which a strong magnetic field holds
the plasma together while its ions and electrons are heated by
microwaves or other energy sources, and inertial confinement, where a
tiny pellet of frozen hydrogen is compressed and heated by intense
pressure so quickly that fusion occurs before the deuterium and tritium
atoms can fly apart from each other. This level of pressure may be
attained by utilizing a powerful laser or a heavy ion beam.
If successful, fusion devices for energy production are expected to
be relatively environmentally friendly, producing no combustion
products or greenhouse gases. While fusion is a nuclear process, the
products of a fusion reaction are not intrinsically radioactive and
cannot themselves be weaponized. Relatively short-lived radioactive
material ( 100 years, compared to thousands of years for some nuclear
fission products) would result from interactions of the fusion products
with the reactor wall. A long-term, large-scale geologic repository for
waste from fusion would be unnecessary. Fusion also is not dependent on
chain reactions that must be constantly monitored and regulated, so
there should be no danger of a runaway process leading to a reactor
meltdown.
The above are the major reasons why most industrialized nations
pursue fusion research today. However, several significant questions in
this field remain, including:
Can we adequately control a fusion plasma--meaning a plasma that
receives a significant portion of its heat from its own fusion
reactions?
Given the intense heat and neutron flux expected inside a reactor, what
material(s) should be used in the first wall facing a fusion plasma?
Even if all fundamental technical challenges are overcome, how
economical can a fusion reactor be in comparison to other energy
options?
And specifically with regard to inertial fusion:
Can we actually build a system that perfectly implodes and recovers
energy from 10 pellets of hydrogen per second--the currently estimated
rate necessary to produce significant net energy?
DOE Office of Science--Fusion Energy Sciences (FES)
FES is the lead program in the Federal Government that supports
research in the science and engineering required to magnetically
confine plasmas for the purposes of generating net fusion energy. It is
also the lead program that stewards basic research in plasma science,
which has applications in a broad range of areas from microchip
processing to astrophysics. In addition, FES examines the science
underlying what are called ``high energy density laboratory plasmas,''
or HEDLP, which are relevant to current and proposed inertial fusion
energy facilities. However, the Federal Government currently has no
official steward of research in inertial fusion for the purposes of
energy generation. This will be described in greater detail in the
section on the National Ignition Facility below.
ITER
ITER (pronounced ``eater'') is a major international research
project with the goal of demonstrating the scientific and technological
feasibility of nuclear fusion energy. ITER was originally an acronym
for International Thermonuclear Experimental Reactor, but that title
was later dropped due to the potentially negative popular connotation
of the word ``thermonuclear.'' The project's leaders now note that iter
also means ``the way'' in Latin. The project is being designed and
built by the members of the ITER Organization: the European Union,
India, Japan, China, Korea, Russia, and the United States, with
additional partner nations currently under consideration. The ITER
Organization was formally established on October 24th, 2007 following
ratification of the ITER International Agreement by all current
members. The device will be built at Cadarache in southeastern France
with the European Union serving as the host party, and it is scheduled
to begin preliminary operations in 2018.
By roughly 2025, ITER is expected to generate fusion power that is
at least 10 times greater than the external power delivered to heat its
plasma. The project is designed to be the top scientific tool for
exploring and testing expectations of plasma behavior in what is called
the burning plasma regime, wherein the fusion process itself provides
the primary heat source to sustain its high temperatures. A clear and
comprehensive understanding of this type of plasma is needed to
confidently extrapolate its behavior and related control technologies
beyond ITER to a reliable fusion power plant.
The United States will primarily contribute hardware components and
personnel during ITER's construction phase, with nearly all of these
components being manufactured in the U.S. and then shipped to
Cadarache. Throughout this phase, the United States is an equal, non-
host partner responsible for about nine percent of its total
construction cost, though this cost may decrease if additional partners
are added to the ITER Organization. DOE currently estimates the total
U.S. cost in as-spent dollars to be between $1.45 and $2.2 billion,
with an official baseline expected to be determined and announced over
the next year. However, the total international cost for the project
has not been determined because different partners use very different
accounting practices for their contributions. For example, many do not
include contingency, labor, and in some cases not even inflation in
their announced estimates.
The U.S. ITER Project Office is hosted by Oak Ridge National
Laboratory in partnership with Princeton Plasma Physics Laboratory and
Savannah River National Laboratory. Oak Ridge was chosen by the
Department of Energy in large part because its recently commissioned
Spallation Neutron Source facility is considered to be a major success
in billion-dollar level project planning and execution, and the lab is
employing nearly the same management and acquisitions team for the U.S.
ITER contribution.
In FY 2010, the U.S. plans to provide contributions valued at $135
million for the ITER project, which is included in the Facility
Operations budget line in Table 1.
Science
FES's Science subprogram includes several activities, much of which
involve research in the leading configuration for magnetic fusion
devices--including ITER--called the tokamak. Tokamaks, first conceived
of by Russian scientists in the 1950s, are devices that are essentially
toroidally (i.e., doughnut) shaped at their core. External coils induce
magnetic fields which wind around the inside of the toroid and confine
the hot plasma within. The U.S. hosts three major magnetic fusion
facilities, two of which are tokamaks and one is known as a ``spherical
torus,'' which is essentially a uniquely shaped tokamak that, at its
core, appears to be a ball which a narrow hole down its middle. These
facilities include:
DIII-D (pronounced ``D. 3. D.'')--This tokamak
operated by General Atomics in San Diego, CA is the largest
magnetic fusion facility in the United States. It is also
geometrically the closest to the ITER configuration. DIII-D has
unique capabilities to shape its plasma and provide feedback
control of errant magnetic fields that affect the stability of
the plasma.
Alcator C-Mod (pronounced ``ALKator See Mahd'')--This
facility at the Massachusetts Institute of Technology is the
only tokamak in the world operating at and above the ITER
design magnetic field and plasma densities. It also produces
the highest pressure tokamak plasma in the world, approaching
pressures expected in ITER, allowing for materials testing
relevant to both ITER and an eventual fusion power plant.
The National Spherical Torus Experiment--NSTX is a
unique magnetic fusion device that was constructed by the
Princeton Plasma Physics Laboratory (PPPL) in collaboration
with the Oak Ridge National Laboratory, Columbia University,
and the University of Washington at Seattle. Its spherical
torus configuration may have several advantages over
conventional tokamaks, a major one being the potential ability
to confine a higher plasma pressure for a given magnetic field
strength, which could enable the development of smaller, more
economical fusion reactors.
In addition to direct research on these facilities, the Science
subprogram also supports research in:
Non-tokamak magnetic fusion concepts and experiments
of various sizes and shapes at several universities and
national laboratories
High Energy Density Laboratory Plasmas (HEDLP), which
are relevant to current and proposed inertial fusion facilities
as well as the understanding of various astrophysical phenomena
such as supernovae
Theory and advanced simulation of fusion plasma
behavior
Basic plasma science
Facility Operations
The mission of the Facility Operations subprogram is to provide for
the operation, maintenance, and enhancements of the three major fusion
research facilities--DIII-D, Alcator C-Mod, and NSTX--to meet the needs
of the scientific collaborators using the facilities. In addition, this
subprogram is responsible for the execution of new projects and
upgrades of major fusion facilities, such as installation of new
diagnostics, in accordance with the Office of Science's project
management standards and with minimum deviation from approved cost and
schedule baselines. As noted above, Facility Operations also includes
the U.S. contributions to the ITER project.
Enabling R&D
The Enabling R&D subprogram focuses on developing and continually
improving the hardware, materials, and technology that are incorporated
into existing fusion research facilities, thereby enabling these
facilities to achieve higher levels of performance within their
inherent capability. Enabling R&D efforts also develop near-term
technology advancements enabling U.S. researchers, through
international collaborations, to access plasma conditions not available
in domestic facilities. In addition, this subprogram supports the
development of new hardware, materials and technology that are
incorporated into the design of next generation facilities to increase
confidence that the predicted performance of these new facilities will
be achieved.
National Ignition Facility and Inertial Fusion Energy Research
The National Ignition Facility (NIF), located at Lawrence Livermore
National Laboratory in Livermore, CA, is the largest inertial fusion
facility in the world. Its construction was certified complete on March
31, 2009, and the facility was officially dedicated on May 29, 2009
with experiments beginning in June. NIF's construction was supported
entirely by DOE's National Nuclear Security Administration (NNSA), not
FES. The total cost to build the facility was approximately $3.5
billion. Its primary mission is to produce data relevant to ensuring
the reliability of the U.S.'s nuclear weapons stockpile through the
study of controlled fusion events similar to the detonation of a
thermonuclear warhead.
To do this, NIF's designers created the world's largest and
highest-energy laser, which can be used to form 192 powerful laser
beams. In 2010, NIF will begin experiments that will focus all of these
beams on a BB-sized target filled with deuterium and tritium fuel.
NIF's researchers believe that by 2012, they will be able to
consistently implode these pellets, igniting the fusion process and
creating the first man-made fusion system to produce more energy than
it uses.
While this facility was not primarily designed for energy research
applications, the achievement of net fusion energy production in NIF
may become strong justification for a significant inertial fusion
energy program. At this time, however, neither NNSA nor FES, nor DOE as
a whole, has determined which (if either) subagency would take a
leading role in developing such a program, nor determined how such a
program would be stewarded in the future. Until FY09, a small inertial
fusion energy research program had been funded solely through
Congressional direction at NNSA. Recently, in the FES section of the
Conference Report for the Energy and Water Development Appropriations
Act, 2010, DOE was directed to review an inertial fusion energy
research project at the Naval Research Laboratory and report on its
findings within 60 days. The Conference Report also states: ``The
conferees encourage the Secretary to explore all possible opportunities
to ensure that this program, which offers unique potential for long-
term energy independence, is not abandoned for lack of a bureaucratic
home.''
Chairman Baird. This hearing will now come to order.
I want to wish everyone a good morning and welcome them to
our hearing on the next generation of fusion energy research.
Before we get started, we have Congressman Rush Holt of New
Jersey with us in the Committee today. If there is no
objection, I would ask unanimous consent that he join us on the
dais. Hearing no objections, so ordered. Thank you for being
here, wherever--where is Rush? Oh, hey Rush. Come on up. We
will begin today--Rush, thank you for joining us. Your
expertise will be much appreciated on this committee along with
that of Dr. Ehlers.
Fusion energy has successfully powered the sun and the
stars for billions of years, so it is no surprise that
humankind has tried to recreate and harness this energy here on
Earth. However, we all know that a working fusion reactor has
been much more difficult to achieve than our Atomic Age
scientists initially expected. Over the years, there were also
some overly optimistic or even, in some cases, fraudulent
proclamations by folks who skipped the peer review process and
went straight to the media, which has further complicated the
popular and political assessment of the extent to which the
Federal Government should continue to support this research.
That said, however, according to recent reviews by the
National Academies and the Department of Energy, there have
been significant developments in the fields of advanced
computing, engineering and plasma science over the last 20
years that have led to a far better understanding of how to
create and control a fusion system. Within about three years
time, the National Ignition Facility in California is expected
to become the first fusion device in the world to produce more
energy than it consumes, though only for at most a handful of
brief experiments per day. In Cadarache, France, the large
international fusion project called ITER is about to begin
construction. This experiment is designed to produce five times
more energy than it consumes for several consecutive hours--I
think my children already do that, however, they are four and a
half years old, and I swear they put more energy out than they
consume--as well as 10 times more for at least 500 seconds.
That is the expectation, at any rate.
If these new facilities are successful, they will represent
a dramatic turning point in developing a viable commercial
fusion reactor. Big questions still remain, however, such as
how affordable fusion can be in comparison to other options
that are known already to produce greater amounts of energy,
and what the appropriate choices are for materials in a device
which contains gases that can be hotter than the sun. But the
U.S. fusion program needs to do all it can to ensure these
successes and be ready to take advantage of them if and when
they occur.
I look forward to learning more from this excellent panel
of witnesses on how this program should evolve in light of
recent developments.
[The prepared statement of Chairman Baird follows:]
Prepared Statement of Chairman Brian Baird
Fusion energy has successfully powered the sun and the stars for
billions of years, so it's no surprise that man would try to recreate
and harness this energy source here on Earth. However, we all know that
a working fusion reactor has been much more difficult to achieve than
our atomic age scientists initially expected. Over the years, there
were also some overly optimistic or even fraudulent proclamations by
self-identified fusion researchers who skipped the peer review process
and went straight to the media, further complicating the popular and
political assessment of the extent to which the Federal Government
should continue to support this research.
That said, according to recent reviews by the National Academies
and the Department of Energy, there have been significant developments
in the fields of advanced computing, engineering, and plasma science
over the last twenty years that have led to a far better understanding
of how to create and control a fusion system. Within about three years
time, the National Ignition Facility in California is expected to
become the first fusion device in the world to produce more energy than
it consumes, though only for at most a handful of brief experiments per
day. And in Cadarache, France, the large international fusion project
called ITER is about to begin construction. This experiment is designed
to produce five times more energy than it consumes for several
consecutive hours, as well as 10 times more for at least 500 seconds.
If these new facilities are successful, they will represent a
dramatic turning point in developing a viable, commercial fusion
reactor. Big questions will still remain, such as how affordable fusion
can be in comparison to other options, and what the appropriate choices
are for materials in a device which contains gases that can be hotter
than the sun. But the U.S. fusion program needs to do all it can to
ensure these successes, and be ready to take advantage of them if and
when they occur.
I look forward to learning more from this excellent panel of
witnesses on how this program should evolve in light of recent
developments, and with that I yield to our distinguished Ranking
Member, Mr. Inglis.
Chairman Baird. We are waiting for Mr. Inglis but I would--
how would you like to proceed, Vern? Do you want to make an
opening comment or----
Mr. Ehlers. Thank you, Mr. Chairman. I am just sitting in
briefly for the Ranking Republican on this committee, who will
make a grand entrance shortly, I am sure.
But I really appreciate, Mr. Chairman, you holding this
hearing. This is an issue that has really dominated long-range
energy thinking for many years but has had very little public
successes to back up the standing that they had hoped to
achieve, and I hope, sincerely hope that we can learn a lot
more about fusion and energy not only in this hearing but in
the next five years and really be able to put it in its
rightful place in the hierarchy of energy alternatives that we
should be pursuing. It is clear to us that we have to take a
different approach in our society in terms of the generation
and use of energy. We know much of what we have to do to change
our use of it. We even know a great deal about what we have to
do to develop alternative methods of producing usable energy
but we certainly don't know as much as we need to know about
fusion energy and what role it can and should play in the
future.
So I thank you for holding this hearing, and I will yield
back.
Chairman Baird. Thank you, Dr. Ehlers.
If other Members wish to submit additional opening
statements, those statements will be added to the record, and
of course, when Mr. Inglis arrives we will accept his statement
as well.
[The prepared statement of Mr. Costello follows:]
Prepared Statement of Representative Jerry F. Costello
Good Morning. Thank you, Mr. Chairman, for holding today's hearing
to examine the fusion energy research activities conducted by the
Department of Energy's (DOE) Office of Science.
In order to develop a sustainable energy policy we must develop and
demonstrate sources of energy that will reduce our dependence on
foreign oil, improve our greenhouse gas emissions, and satisfy our
energy needs. Fusion energy should play an integral role in providing a
substantial amount of clean, domestic energy to our communities and
industry without the risks of nuclear energy.
I am interested to hear from our witnesses today how this committee
can work with DOE to ensure that we are using cutting-edge technology
and providing appropriate levels of funding for fusion energy research.
In particular, what timelines are in place to move current research
efforts to the development and demonstration and eventually to large-
scale commercialization. In addition, I would like to learn more about
the international research collaborations on fusion energy and how this
committee and the Federal Government can work with the international
community on fusion research efforts while continuing to take the lead
on these important efforts.
I welcome our panel of witnesses, and I look forward to their
testimony. Thank you again, Mr. Chairman.
[The prepared statement of Ms. Johnson follows:]
Prepared Statement of Representative Eddie Bernice Johnson
Mr. Chairman I would like to thank you and the Ranking Member for
holding this important hearing today on the future of fusion energy
research.
I am please to welcome our witnesses, and look forward to their
testimony.
Fusion energy is one of the most innovative and essential research
projects occurring in this country and around the world.
As a safe, abundant and clean form of energy, the future of fusion
is truly the future of energy independence in America.
Since the development of nuclear weapons in the 1940s, we've been
working on research to harness that type of power into an energy
source.
While fission has been successfully developed, fusion has proved
more elusive.
There are currently several pivotal projects in fusion energy
research.
One of those projects that I remain most interested and optimistic
about is the international ITER (pronounced eater) research project.
The research they are doing in plasma behavior should prove
essential in the generation of fusion power.
I am also interested in hearing about our domestic magnetic fusion
research and facilities. They are playing a key role in many aspects of
the future of fusion.
I look forward to hearing more about this project from our
witnesses.
I am pleased that the Science Committee is holding this hearing
today and believe we need to continue to take a proactive role in
encouraging Congress and the Administration to invest more in energy
research and development.
Witnesses, many of you represent the future of innovation in energy
research. Once again, I welcome you and appreciate your contributions
to today's hearing.
Thank you, Mr. Chairman. I yield back.
Chairman Baird. At this point it is my pleasure to
introduce our extraordinarily distinguished panel of expert
witnesses. Dr. Edmund Synakowski is the Director of the Office
of Fusion Energy Science at the U.S. Department of Energy. Dr.
Riccardo Betti is the Assistant Director of Academic Affairs
for the Laboratory for Laser Energetics at the University of
Rochester. Dr. Raymond Fonck is a Professor of Engineering
Physics at the University of Wisconsin, and I will yield to our
distinguished Chairman and then following that--well, I was our
distinguished Chairman. I will yield to--oh, Bart, I didn't see
you were here. It is our distinguished Chairman, Mr. Gordon. I
didn't see you. Mr. Gordon is here, of course, to introduce Dr.
Thom Mason, Director of Oak Ridge National Lab.
Chairman Gordon. Thank you, Dr. Baird, and, you know, as I
have said before, you have been the workhorse, this has been
the workhorse Subcommittee for our Full Committee, and I thank
you for another very excellent hearing with an outstanding
group of witnesses. Thank you all for coming.
I am pleased to have the opportunity to welcome to the
Subcommittee today an adopted Tennessean and the Director of
the Oak Ridge National Lab, Dr. Thom Mason. Dr. Mason earned
his Ph.D. in experimental condensed matter physics, something
that Mr. Davis and I talk a lot about. After touring the world,
he came to Oak Ridge in 1998, and in 2001 he was named Director
of the lab's Spallation Neutron Source project, an impressive
$1.4 billion project that was finished on time and under budget
and at Oak Ridge now. Then later in 2007 he became Director of
the lab at Oak Ridge. He is going to describe today his
critical role in managing the U.S. contribution to the ITER
reactor. They are in east Tennessee, I am in middle Tennessee,
but Mr. Davis represents many of the folks that work there so I
will yield to Mr. Davis to pander for a few minutes.
Mr. Davis. I am glad you said a few minutes. It takes me a
long time to get words out. I speak a little bit slower than
perhaps some folks.
Mr. Chairman, thank you for the work that you do on this
committee and we in Tennessee are certainly lucky and very
proud of the accomplishments that you have, and Bart and I
represent an area that has in it the Cumberland Mountains, and
our folks there say they are proud to say they have two
Congressmen. I think they are prouder of Bart Gordon probably
than of me since he is Chairman of this committee.
I would like to add to what comments you just made, and I
would like to add that Oak Ridge is a pillar of the community
in Tennessee, supporting world-leading research initiatives in
energy, environment, national security and computing as well as
providing good jobs and performing educational outreach to our
students. We are lucky to have this critical scientific
resource in our region with such an accomplished and dedicated
scientist and leader as you are. Dr. Mason, I am very happy
that you are here today to provide valuable insights on the
future of fusion research, both at Oak Ridge and abroad. I look
forward to your continued strong leadership at this laboratory
in Oak Ridge. It has been great working with you, and as I
travel to Oak Ridge to the lab, or whether its at the
Spallation Neutron Source or the NNSA (National Nuclear
Security Administration) at Y-12, I realize that this area of
the world, this area of America, and this part of Tennessee,
has been a valuable asset in scientific research and will
continue under your leadership. Thank you for being here.
Chairman Baird. I thank our Oak Ridge boys for their
introduction. I apologize to the Chairman. I hadn't seen you
here, Mr. Chairman, so I was puzzled by what appeared to be a
strange third-person self-reference here.
I would now be happy to recognize our guests at the
Committee, Representative Rush Holt, to introduce our last
witness, and Mr. Holt will be followed by Dr. Ehlers, who
wishes to offer comments as well.
Mr. Holt. I thank the Chair and I am pleased to be with you
and my distinguished colleagues today, and also with the
distinguished panel. I have been asked to introduce Dr. Prager,
and I could equally well spend time introducing and praising
Dr. Synakowski, Dr. Fonck, all three of whom have been
constituents in the 12th Congressional District in New Jersey,
but more importantly, all three of whom have been leaders,
world leaders, in advancing plasma physics and fusion sciences.
They all have contributed to what we now see, the promise of
fusion with essentially unlimited, globally available
ingredients, with great environmental attractiveness, with no
harmful emissions or high-level radioactive waste or connection
to proliferations of weapons materials--in other words, a
technology well worth undertaking. They have--they will be well
prepared to address today how realistic and practical this may
be, I would say at least possibly and I would go as far as to
say probably. The progress has been great by any measure
exceeding predictions. Certainly if you look at achievements
per dollar spent, in power contained, millions of watt and
plasma sustained, improvements by factors of hundreds of
thousands to what amounts to an eternity in plasma lifetimes,
development of an entire new field of science, plasma physics,
with theoretical and practical contributions, not just to
materials and engineering and science but to daily lives. The
progress, the promise, the justification of spending taxpayer
dollars, significant taxpayer dollars, have been recognized by
domestic and international advisory committees, in some cases
on which our panelists have served or which they have chaired,
and also recognized by the actions of many other countries. It
is worth noting as we talk about the fusion energy program in
the United States that the United States was once for decades
the world leader. We could be again. We should be again for a
lot of reasons. If we are, it will be in part because of the
work of some of these panelists.
Dr. Prager has worked at a number of the places where this
significant work has been done: General Atomics in San Diego,
Columbia University in New York, University of Wisconsin for
many years, and he has chaired the Fusion Energy Advisory
Committee, and he has chaired the Division of Plasma Physics of
the American Physical Society. You will notice I spoke earlier
of creating an entirely new field of science growing out of the
work of Lyman Spitzer at Princeton 40, 50 years ago now. Dr.
Prager also served as President of the University Fusion
Association, so he represented the large academic contributions
of this field as well. He is a recipient of the Dawson Prize
and the Leadership Award of Fusion Power Associates. So I am
pleased to introduce Dr. Prager but also commend to you, all of
the panelists, whom I know personally and cannot praise highly
enough. Thank you.
Chairman Baird. Thank you, Dr. Holt.
Dr. Ehlers.
Mr. Ehlers. Thank you, Mr. Chairman, just a brief comment
in view of the comments of the two gentlemen from Tennessee
sitting on the dais here and especially to our chairman, Mr.
Gordon. When he was making--they were making their comments
about Oak Ridge, it suddenly occurred to me, it has been at
least 30 years since I have been to Oak Ridge. It has been
probably 20 since I have been to Argonne and 10 since I have
been to Fermilab. Members of the Committee, these are the crown
jewels of our research effort, and I think Members of the
Committee should be visiting these laboratories more often. So
my plea to Chairman Gordon is, perhaps we could start
organizing CODELs where Members of the Committee can go visit
the national labs on a rotating basis. I think it would be
extremely beneficial for the Members of the Committee. Yield
back.
Chairman Baird. I hear there are visa problems for some of
us to get into Oak Ridge.
We have been joined by the Ranking Member, Mr. Inglis, and
we will recognize him. First we will welcome him. I know he had
a panel he was attending prior to this so I appreciate his
presence, and thank you, Dr. Ehlers, for so ably filling the
role in the absence of Mr. Inglis. Welcome.
Mr. Inglis. Thank you, Mr. Chairman.
Well, I think that Dr. Ehlers filled in very well and I
thank you, Dr. Ehlers, for filling in. I am looking forward to
hearing the testimony because it is very important and very
exciting. The key question is how to make it work. So looking
forward to learning more from you.
So thank you, Mr. Chairman, for holding the hearing.
[The prepared statement of Mr. Inglis follows:]
Prepared Statement of Representative Bob Inglis
Good morning and thank you for holding this hearing, Mr. Chairman.
It's probably fair to say that when it comes to fusion, we're
talking about the Holy Grail of energy. For the past 50 years, fusion
has given us hope as an abundant, clean, secure, and safe source of
energy. We've been investing in that hope, learning more about fusion
and gaining critical technical knowledge. We've also identified more
questions that need answering to turn fusion into the energy solution
we're looking for.
Today our witnesses will help us understand where we stand on the
road to fusion power. The recent capital investments in the National
Ignition Facility at Lawrence Livermore National Lab and the
international ITER project have been substantial. We need to understand
what these investments will deliver and if these types of investments
are getting the most out of scarce federal dollars. We also need to
identify where the unique intellectual capital and innovative power of
the United States should be put to work to crack the code to fusion
energy.
I'd like to think that if we play our cards right, the materials,
devices, and technologies necessary to turn fusion into electricity can
be developed right here at home. That's why I joined Rep. Lofgren in
co-sponsoring the Fusion Energy Science and Fusion Energy Planning Act
of 2009. This bill will strengthen our fusion engineering research
program and prepare the U.S. to lead on key research areas.
I'm hopeful that we'll find the way to practical fusion energy, but
I also realize that it must be proved. I hope our witnesses can help us
balance the marvelous prospect of a fusion-powered economy tomorrow
with the responsibility to bring reliable forms of power to the market.
Mr. Chairman, thank you again for holding this hearing. I look
forward to hearing from the witnesses and I yield back the balance of
my time.
Chairman Baird. One of the things I greatly respect about
Mr. Inglis is, he recognizes when everybody has said everything
and he doesn't have to say it again. That is a rare quality in
Congress, and with that, we will proceed to our experts and I
will begin with Dr. Synakowski. Thank you very much.
STATEMENT OF DR. EDMUND J. SYNAKOWSKI, ASSOCIATE DIRECTOR FOR
FUSION ENERGY SCIENCES, OFFICE OF SCIENCE, U.S. DEPARTMENT OF
ENERGY
Dr. Synakowski. Thank you, Mr. Chairman, Ranking Member
Inglis and Members of the Committee.
I have been Director of the Federal Fusion Energy Sciences
Program since June 7 of this year, and I am thrilled to join
this office when the scientific readiness, opportunity and
urgency of fusion are extraordinarily resonant.
The pursuit of fusion energy embraces the challenge of
bringing the power of a star to Earth. Fusion's promise is
enormous--nearly limitless fuel supplies, large-scale energy
production, no greenhouse gas emissions. We are entering a new
age in fusion science during which our knowledge base will be
put to the test as researchers will undertake a fundamental set
of new studies of fusion energy's viability.
At the heart of fusion energy in the stars and on Earth is
the world's most famous equation, E = MC2, which
describes the fundamental relationship between mass and energy.
The challenge is getting atomic nuclei of the fuel to bind
together to form heavier elements, releasing enormous
quantities of energy in the process. In the lab we use hydrogen
isotopes as the fuel, and I have had the privilege of being
part of experiments that have generated millions of watts of
fusion power.
The science underpinning much of fusion energy research is
plasma physics. Plasmas are hot gases, the stuff of stars, and
over 99 percent of the visible universe, lightning, flames.
Plasmas are routinely confined by magnetic fields and heated in
laboratories to fusion conditions. The tokamak, a Russian
invention from the 1960s, is studied worldwide and is the
leading candidate ``magnetic bottle'' for creating fusion
energy.
Dramatic progress prompted the National Academy of Sciences
in 2004 to urge the United States to take a landmark step: it
should participate in a fusion experiment in which the plasma
burns, or generates more energy than is used to heat it
externally and in large part, heats itself. In response, the
United States agreed to participate in the ITER project to be
built in Cadarache, France. We view ITER as a scientific
instrument with the flexibility to reveal critical requirements
for fusion's optimization. The seven members of ITER are China,
the European Union, India, Japan, Russia, South Korea and the
United States. Construction will take place over the next
decade with burning plasma experiments slated to take place in
the 2020s. The United States is committed to bringing a strong
and effective approach to project management in ITER's design
and construction.
Another approach to fusion is to compress the fuel
extremely rapidly and to rely on its inertia to confine it long
enough for fusion to occur. This is being studied by the
National Nuclear Security Administration (NNSA) for stockpile
stewardship applications and a joint program to study this
extraordinary state of matter is being forged between NNSA and
my office that will engage a broad array of laboratories and
universities. Tests of this approach are being planned for the
National Ignition Facility. If successful, they will be
historic. The National Academy of Sciences has emphasized the
importance of studying this plasma state to both energy
research and to a rich array of scientific questions.
ITER's success, its chances of success and our prospects
for deep scientific return are intimately interwoven with a
broad domestic research program in the fusion-related sciences.
In the United States, our multi-institutional program in
experiment, theory and computation is rich in discovery and
impact. It is globally respected for its depth, accomplishment
and scientific aesthetic and has had a major impact on the ITER
design and research plan. Research is supported in 38 states at
national labs, private industry and about 60 universities. U.S.
researchers participate in about 75 joint international
activities and about 340 graduate students partake in fusion
energy and general plasma science research.
Strategic planning is underway aimed at filling gaps in the
world so as to assert U.S. leadership where it best advances
fusion as a whole while maximizing U.S. scientific return. For
magnetic fusion, the scientific challenges can be broadly
stated as follows. First, understanding and optimizing the
burning plasma state. Experiments, theory and simulation have
significantly advanced our understanding of what to expect from
a burning plasma, and will continue to do so, but ITER provides
the only platform planned to directly test and expand our
understanding of this complex physics.
Second, understanding the requirements for extending the
burning plasma state to long times--days, weeks, and longer.
Many aspects of this are pursued in the United States, and the
second 10 years of ITER's operation will put our understanding
to crucial tests. However, overseas fusion programs are set to
assert leadership in part through new billion-dollar class
research facilities in Europe, Japan, South Korea and China. We
are exploring growing our collaborations to increase their
impact and the knowledge returned.
And finally, third, advancing the materials science for
enduring the harsh fusion plasma environment, for extracting
energy and for generating fusion fuel in situ. We will be
exploring what is required to develop a materials and fusion
nuclear science program, one that addresses the necessary
fundamental scientific issues, while weaving the results and
advances into our best concepts of future fusion systems.
Thank you, Mr. Chairman, for providing this opportunity to
discuss the Fusion Energy Sciences Program. This concludes my
testimony, and I would be pleased to answer any questions you
may have.
[The prepared statement of Dr. Synakowski follows:]
Prepared Statement of Edmund J. Synakowski
Thank you Mr. Chairman, Ranking Member Inglis, and Members of the
Committee for the opportunity to appear before you to provide testimony
on the Fusion Energy Sciences program in the Department of Energy's
(DOE's) Office of Science (SC). I have been Director of the Office of
Fusion Energy Science since June 7th of this year. It is a privilege to
lead the Nation's fusion energy sciences program following a career of
scientific research and service at two national laboratories and in
research collaborations with national labs and universities. I am
thrilled to have joined this Office when the scientific readiness,
opportunity, and urgency in fusion are extraordinarily resonant. I am
pleased to share with you my perspectives on the status and the
strategy for advancing fusion as we enter a new and critical age in its
research and development.
Introduction
The pursuit of fusion energy embraces the challenge of bringing the
energy-producing power of a star to Earth for the benefit of humankind.
The promise is enormous--an energy system whose fuel is obtained from
seawater and from plentiful supplies of lithium in the Earth, whose
resulting radioactivity is modest compared to fission, and which yields
zero carbon emissions to the atmosphere. The pursuit is one of the most
challenging programs of scientific research and development that has
ever been undertaken. A devoted, expert, and innovative scientific and
engineering workforce has been responsible for the impressive progress
in harnessing fusion energy since the earliest fusion experiments over
sixty years ago. As a result we are on the verge of a new age in fusion
science during which researchers will undertake fundamental tests of
fusion energy's viability. The scientific community's excitement and
optimism about our progress and readiness to enter this new era of
fusion research is amplified by the high awareness worldwide of the
need to fundamentally alter our energy landscape in this century.
Fusion can be part of that landscape shift. But it is no secret that
fusion on Earth is difficult. Establishing a deep scientific
understanding of the requirements for harnessing and optimizing this
process on Earth is critical, and the progress has been dramatic.
The Scientific Challenges of Fusion Energy
The science underpinning much of fusion energy research is plasma
physics. Plasmas--the fourth state of matter--are hot gases, hot enough
that electrons have been knocked free of atomic nuclei, forming an
ensemble of ions and electrons that can conduct electrical currents and
can respond to electric and magnetic fields. The science of plasmas is
elegant, far-reaching, and impactful. Comprising over 99 percent of the
visible universe, plasmas are also pervasive. It is the state of matter
of the sun's center, corona, and solar flares. Plasma dynamics are at
the heart of the extraordinary formation of galactic jets and accretion
of stellar material around black holes. On Earth it is the stuff of
lightning and flames. Plasma physics describes the processes giving
rise to the aurora that gently illuminates the far northern and
southern nighttime skies. Practical applications of plasmas are found
in various forms of lighting and semiconductor manufacturing, and of
course plasma televisions.
At the heart of fusion energy in the stars and on Earth is the
world's most famous equation, E = mc2, which summarizes our
understanding of how mass can be converted into energy. Inside the sun,
plasma pressures are high enough that hydrogen nuclei frequently
collide and fuse into new atomic nuclei. The end product of these new
fused systems actually weighs less than the original nuclei; the
``missing'' mass is converted into the motion of the byproducts of the
collisions, releasing prodigious quantities of energy. The energy
released by fusion is largest per unit mass for the lightest elements.
Thus, scientists also choose hydrogen isotopes to achieve fusion on
Earth.
On Earth, fusion is in fact routinely created and controlled in our
fusion research laboratories--for example, I've had the privilege of
being part of and of leading experiments that have generated millions
of watts of fusion power for seconds at a time. In our vision of a
working reactor, some of the energy will be captured by the plasma
itself, and the plasma will self-heat, enabling more fusion to take
place. The energy of the fusion reaction byproducts--energetic ions and
neutrons--escaping the plasma will be captured and converted into heat.
This heat will drive conventional power plant equipment to boil water,
generate steam, and turn turbines to put electric power on the grid.
The leading challenge for fusion is stable confinement and control
of the hot plasma. When a plasma gets hot enough for fusion to occur,
its strong tendency is to expand and cool like any gas. If allowed to
do this too quickly, the conditions that enable fusion are lost. If
this same hot plasma strikes a material wall before fusion can take
place, it also cools and fusion ceases. Thus the hot plasma must be
confined for a long enough time away from a material container. The
leading approach to fusion energy being pursued in the world is to
confine the hot fusion fuel with magnetic fields. The insulating
properties of magnetic fields, properly configured, can be
extraordinary. In present experimental devices, temperatures of plasmas
are found to increase tens of millions of degrees centigrade in a
matter of a few centimeters--from the room-temperature vessel
containing the hot plasma into the plasma itself. Another approach is
to compress the fuel rapidly so as to reach fusion conditions and rely
on the inertia of the fuel itself to keep it combined long enough for
fusion to happen. This approach is being studied by the National
Nuclear Security Administration (NNSA), and a joint program researching
this state of matter is being forged between NNSA and my office.
A second great challenge for fusion is materials that can tolerate
the extreme conditions of a fusion reactor. A plasma at a high enough
temperature and density to undergo nuclear fusion in a reactor, while
generating close to a billion watts of fusion power, will present a
uniquely hostile environment to the materials comprising the reactor.
The extreme heat fluxes inflicted on a reactor vessel's walls--at rates
of tens of millions of watts per square meter--present significant
materials challenges. Furthermore, in a fusion reactor the materials
that will be near the burning plasma will bathe in a harsh shower of
neutrons that can displace its constituent atoms and thus alter its
strength and other material qualities. Advances in material science
will be required to achieve reactor components that can withstand
exposure to the enormous heat and neutron fluxes emanating from
prolonged fusion burns.
In the last two decades, progress in our understanding of plasma
systems and their control requirements has enabled the fusion community
to move to the edge of a new era, the age of self-sustaining
``burning'' plasmas. For both lines of research described above,
magnetic and inertial fusion, new experimental plans are being
developed to make historic first studies of fusion systems where the
energy produced by the fusion process itself is substantially greater
than the energy applied externally to heat and control the plasma. In
this testimony, I describe the current frontiers for the fusion energy
sciences and describe how the research programs of the Office of
Science contribute to scientific advances in these areas. I will
discuss our program's relationship to international partners and the
anticipated benefits of continued U.S. leadership, including benefits
to science and to the Nation. I will also describe activities in our
own program in the U.S. for building the science that is enabling us to
enter the burning plasma era. To begin, however, I would like to
briefly describe the origins and scientific breadth of fusion research.
A Brief History of Fusion Energy Sciences Research in the U.S.
The advent of the nuclear age in the mid-20th century led
scientists to consider whether the nuclear fusion process could be
harnessed on Earth for energy production. In the United States,
interest in the possibility of controlled fusion dates back even prior
to the end of World War II. From 1944 to 1946, frequent and lively
discussions of the subject were held among scientists assembled at the
Los Alamos Scientific Laboratory, particularly E. Fermi, E. Teller,
J.L. Tuck, S. Ulam, J. Wheeler, and R.R. Wilson. In the wake of the
Manhattan Project, optimism for fusion energy ran high. Many
scientists, flush with excitement and confidence from the rapid success
of fission research, expected similarly expeditious progress towards
controlled fusion. Most of the basic principles of fusion, if not
already known, were formulated at that time, and a number of
suggestions were made for achieving controlled thermonuclear fusion
conditions. While many of these early suggestions were highly
ingenious, all failed to meet the basic requirements of a controlled
fusion device. From 1951 until 1958, fusion energy research continued
under a classified program named ``Project Sherwood.'' By the mid-
1950's, about 200 personnel were involved in the U.S. in magnetic
fusion research, designing and testing various approaches for
``magnetic bottles'' to confine the hot plasma.
By the mid-1950s, it was apparent that the underlying physics of
the plasma state was proving to be far more complex and difficult to
control than had been anticipated. The research in magnetic fusion was
declassified in 1958, and at that time it was seen that the U.S.,
Soviet, and British-led fusion research programs were neck-and-neck--
and far from achieving a usable energy source. Each program was only
capable of producing plasmas that were, according to a standard
measure, about ten thousand times lower than required for fusion to
generate more heat than was required to create the fusing plasma in the
first place. Throughout most of the 1960's, research in fusion
progressed through small-scale laboratory experiments and research into
fundamental plasma theory. It became clear that cracking the nut of the
fusion energy challenge was going to take far more basic physics
research than predicted at the program's outset.
Much of the research through the 1960's focused on an approach
where the magnetic field for confining the plasma was completely
defined by the hardware of the experiment. In 1968, however, a major
breakthrough was announced by Soviet researchers. They introduced a
clever innovation wherein some of the magnetic field for confining the
plasma was created by an electrical current passed through the plasma
itself. This led to a dramatic simplification in the magnetic coils
needed externally. The announced results were stunning to researchers--
plasma performance measured in terms of confinement quality were said
to be improved by an order of magnitude. In fact, the results were so
surprising that many in the West did not believe them. In an event
extraordinary for the times but emblematic of how science is best
carried out, the leader of the Soviet fusion effort opened the door to
British scientists in 1969. They brought their own measurement
equipment to the Soviet Union and confirmed the Soviet claims--the
plasma quality was far superior to any that had been created in any
other experiment to date. The results led to the conversion of U.S.
research facilities to this new concept called a tokamak, a name based
on a Russian acronym for ``toroidal (donut-shaped) chamber with a
magnetic coil.''
These developments expanded our view of what was possible in fusion
research. In the 1970's, progress was rapid, and budgets for fusion
research in the U.S. increased as a result of the energy crisis. New
research facilities were built across the country, including those at
the DOE national labs located at Princeton, New Jersey, Oak Ridge,
Tennessee, and Livermore, California. A major industrial research
endeavor was also begun through a contract with General Atomics in La
Jolla, California. University research grew. The theory and computation
efforts that accompanied and supported development and interpretation
of these experiments grew as well. International research programs also
were ambitious, with the largest facilities in the world being
constructed in the United Kingdom and Japan.
Scientific progress was strong through the 1980's, despite
declining budgets. Major choices were made in program direction, and
the tokamak concept was selected as the leading contender to reach the
promised land of creating a sustained, magnetically confined burning
plasma on Earth. In the 1980's research began on the flagship Tokamak
Fusion Test Reactor (TFTR) at Princeton, and mid-decade a remarkable
achievement was realized. Temperatures of the plasma fuel reached over
200 million degrees Centigrade--ten times the core temperature of the
sun--in these magnetically confined plasmas. The flexibility of this
experiment proved to be of great scientific value in launching
controlled research studies of this plasma state. The exciting TFTR
results were joined by rapid progress at the DIII-D tokamak at General
Atomics in La Jolla, and a healthy competition grew within the U.S. as
well as internationally. At this time, complementary experiments were
continued at MIT in compact devices of very high magnetic field. The
Joint European Tokamak (JET) in England was the first to use the ``high
octane'' mix of the hydrogen isotopes deuterium and tritium (D-T) that
will be used in a first-generation fusion reactor. They soon announced
to the world the generation of a few million watts of fusion power,
enough to power thousands of homes. The race was on--TFTR at Princeton
began its experimental campaign with the D-T fuel mix, and completed it
with experiments in 1994 that generated over 10 million watts of fusion
power. The JET experiment ultimately created a record 16 million watts
of fusion power in 1997, a result enabled by the larger size of the
device as compared to TFTR.
Notably, however, more power was used to heat and control the
plasma in each of these cases than was used to create the fusion
reactions themselves. The figure of merit used in magnetic fusion, Q,
relates the fusion power created to the power used to heat the plasma.
The JET experiment yielded a Q of about 0.6. A campfire analogy is
that, to date in fusion research, we have been burning wet wood. Remove
the external flame, and the fire goes out. Extending the analogy, we
have learned a great deal during and since these research campaigns
about how to make a fire and how to make a fusion fireplace in which
the wood burns itself--in which we have a self-sustained ``burning''
plasma.
Today we have to build that fireplace and learn how to best manage
the fire in a robust, attractive way. Results from the D-T TFTR and JET
studies and those obtained worldwide in other experiments pointed to a
common direction, one in which meeting the burning plasma challenge is
going to require an increase in scale of the research device. The
embodiment of these research conclusions is the design and new
construction of the international project called ITER (Latin for ``the
way''), which is described more fully later in this testimony.
It is important to note for understanding the potential future of
fusion research that at least two major research thrusts were
developing in parallel to the magnetic confinement experiments that I
have just described. First, a seminal paper in 1972 pointed out the
potential of the laser, invented in 1960, to be used as the basis of a
fundamentally different approach to fusion energy. This approach,
called inertial confinement fusion, uses symmetrically-applied
exceptionally high-power pulsed laser beams to compress a small pellet
of fusion fuel to high enough densities and temperatures for fusion to
occur. In this case, the inertia of the fuel itself is relied upon to
keep the matter contained long enough for a fusion burn to take place.
The National Nuclear Security Administration (NNSA) has been the
primary supporter of this line of research, through its aim to develop
critical tools for stockpile stewardship. The Office of Fusion Energy
Sciences also has a keen interest in inertial fusion, both from the
point of view of the richness of the plasma physics--more on this
later--as well as its potential energy applications.
NNSA's recently completed National Ignition Facility at Lawrence
Livermore National Laboratory is the world's leading experimental
enterprise in this research, and its work in the emergent field of High
Energy Density Laboratory Plasma (HEDLP) physics is supported stateside
by related research at other national laboratories, the University of
Rochester, and a wide range of university-scale experiments.
Second, the computer revolution had enormous impact on fusion
research in both magnetic and inertial fusion. The fusion sciences have
been transformed from a largely empirical enterprise to a theory-based
dominated by vigorous interaction between those who measure the elusive
qualities and behavior of the plasma state in fusion conditions, and
those who develop its complex theory and represent that theory in
computational models. Over the last twenty years, the scientific basis
for our readiness for the next era of fusion energy research has been
established through this interaction, anchored in flexible, inventive
experiments, continuously growing computational horsepower, and rich
physics challenges that have yielded many secrets of the plasma to our
probing.
In both magnetic fusion energy science and the linked science of
inertial fusion energy, we are at the edge of the burning plasma era. A
burning plasma is fundamentally different from plasmas that have been
created in research facilities to date; it is only in a burning plasma
that the energy confinement, heating, and stability are fully coupled,
and the scientific issues associated with creating and sustaining a
power-producing plasma can be explored. The importance of moving into
this era was strongly affirmed in a 2004 National Academy of Sciences
review, ``Burning Plasmas--Bringing a Star to Earth.'' This report
recognized that a burning plasma experiment is essential to assessing
the scientific and technical feasibility of fusion as an energy source.
Its strongest recommendation was that the U.S. fusion science research
program confront the rich and important scientific questions that will
only be possibly by creating a burning plasma in the laboratory. Even
since this report, our scientific basis for entering this new era has
deepened.
Allow me to now describe for you the present fusion sciences
research program in the U.S., with references to the world-wide effort
that supports our entrance into this new age, and the enabling program
of this new era--the ITER project.
The U.S. Research Program Today
In the United States, a broad, multi-institutional program in
experiment, theory, and computation is executed through the Office of
Fusion Energy Sciences. A national laboratory dedicated to plasma
physics and fusion research is located at Princeton, New Jersey, and
other national laboratories are funded to undertake research in the
fusion sciences as well. Many university partners partake in fusion
research at these laboratories and at their own campuses.
A major feature of the program is the research platform provided by
three major experiments. These facilities and their predecessors have
been crucial for developing the physics basis needed to justify a
burning plasma physics program. Today the experimental research
programs at the U.S. facilities are scientifically complementary.
These are the DIII-D tokamak at General Atomics, mentioned
previously, the National Spherical Torus Experiment (NSTX), at the
Princeton Plasma Physics Laboratory, and a compact, high magnetic field
tokamak called Alcator C-Mod at the Massachusetts Institute of
Technology. Researchers participate in joint experiments conducted
between these facilities and are leaders in an international
organization that develops joint experiments with facilities overseas
as well. U.S. researchers participate in about 75 joint international
activities at the present time. These activities have a common aim,
namely, to develop the scientific basis for a sound and revealing
burning plasma research program and to develop fusion plasma science
more generally. The national laboratories are intimately intertwined in
the research execution and program leadership at these sites.
Significant student populations partake in research there, and their
programs are intrinsically collaborative. In part through student
participation (about 340 graduate students at this time participate in
an aspect of fusion energy science research), these national programs
have strong, productive ties with many universities across the Nation.
Our portfolio also includes a robust program in innovative plasma
confinement concepts, which broadens the fusion program by exploring
the science of confinement optimization and plasma stability through a
variety of smaller novel devices. The breadth of this program is
summarized by the fact that, taken together, these confinement devices
allow scientists to study plasmas with densities spanning twelve orders
of magnitude.
FES also supports a world-leading theory program, which provides
the conceptual scientific underpinning of the magnetic fusion energy
sciences program. This program focuses on three thrust areas: burning
plasmas, fundamental understanding, and configuration improvement.
Theory efforts describe the complex multiphysics, multiscale, non-
linear plasma systems at the most fundamental level. These
descriptions--ranging from analytic theory to highly sophisticated
computer simulation codes--are used to interpret results from current
experiments, plan new experiments on existing facilities, design future
experimental facilities, and assess projections of facility
performance. U.S. expertise and capabilities in theory and computation
are a lynchpin of the transition to the burning plasma era.
The flagship program of this new era is the ITER project, an
international fusion research project being constructed in Cadarache,
France, that will realize magnetically confined burning plasmas for the
first time. Burning plasma physics as it will be explored on ITER
presents at once a grand scientific challenge in its own right and an
undertaking of tremendous practical import. The goal of this
international research program is to demonstrate the scientific and
technological feasibility of sustained fusion power. In the United
States, we place high importance on the potential of ITER as a flexible
instrument for scientific discovery as well as a demonstration of
fusion energy's scientific and technical viability. ITER's overarching
goals are the creation of plasmas producing 500 megawatts of power with
Q = 10 for hundreds of seconds, that is, ten times the fusion power
generated by the burning plasma as compared to the power used to heat
it, and plasmas of Q = 5 for durations of up to an hour. What we learn
through ITER will guide our choices in the development of a subsequent
demonstration power plant.
Seven members comprise the ITER partnership: China, the European
Union, India, Japan, Russia, South Korea, and the United States. Under
the formal international agreement that entered into force in 2006, the
experiment is to be built in Cadarache, France proximal to a major
French nuclear research laboratory. It will be the largest magnetic
confinement fusion experiment ever constructed, with a radius of the
magnetic donut over six meters, enclosed in structure close to 10
stories tall. The magnets will be superconducting so as to enable long
pulses of fusion plasmas. U.S. researchers have played a significant
role in identifying the design for ITER. As host, the European Union
has responsibility for five-elevenths of the project cost. The
remaining six partners, including the U.S., is each responsible for
one-eleventh share. Contributions of the member states are primarily
in-kind hardware components for the project. Annual cash contributions
are also made to the ITER Organization (IO) in Cadarache that is
responsible for assembling the device and the civil construction of the
site. The data obtained from ITER will be shared by all partners.
The U.S. ITER Office (USIPO), located at Oak Ridge National
Laboratory, reports to my office and manages the interfaces with the IO
and the development of the hardware that are a U.S. responsibility.
Most of the funds directed to the USIPO will be spent domestically in
U.S. industry to design and fabricate the hardware needed to fulfill
our obligations. Examples of what we will deliver include
superconducting transformer coils that will reside in the center of the
magnetic donut, superconducting strands of wire to be used in the
construction of some the other magnets for ITER, and measurement
instrumentation systems that will be installed on the device to measure
and monitor many aspects of the burning plasma.
The schedule for ITER operations is being developed and refined;
the first plasma experiments to commission the device are almost
certainly at least 10 years away, with the first burning plasma
experiments probably in the mid-2020's. This time scale is an
acknowledged frustration of all parties given the urgency of the energy
challenge and reflects both the immense technical scope of the project,
the fact that the laboratory and its governance are being set up at a
green field site, and the added challenges posed by a novel
international collaboration. Importantly, the USIPO is vigorously
engaged with the IO in Cadarache and other members' domestic agencies
in implementing U.S. project management practices in ITER. The Office
of Science takes most seriously the imperative that ITER be well
managed in both its construction and research phases.
With respect to burning plasma physics and ITER itself, the U.S.
research program has been particularly effective in improving the ITER
design. For example, the ``dynamic range'' of the plasmas that ITER
will be capable of creating has been significantly increased thanks in
significant part to U.S. intellectual leadership. The U.S. fusion
program's robust interplay among experimentalists, theorists, and
computational researchers in developing complex simulation programs
executed on the world's most powerful computers have been and will
continue to be essential for preparing for the burning plasma era. This
interplay is facilitated by the U.S. Burning Plasma Organization, a
community-led endeavor of researchers currently headed by the chief
scientist of the USIPO.
As described earlier, there is another form of fusion in the
laboratory, inertial confinement fusion, whose science is being pursued
and is also on the cusp of the burning plasma era. The National
Ignition Facility is slated to explore whether a small pellet of fusion
fuel can be ignited in a fusion burn by simultaneously heating and
compressing it with the enormous radiant power of its unparalleled
laser system. If successful, these experiments will be historic--
analogous to achievement of the first spark ever in an internal
combustion engine. Significant scientific and technological development
will be required to achieve appreciable energy output per spark and the
generation of many sparks per second in an attractive manner.
The branch of plasma physics at the heart of this endeavor, high
energy density laboratory plasma physics, studies extreme states of
matter known to exist otherwise only in extraordinary systems such as
stellar interiors and exploding stars. The National Academy of Science
has recognized the importance of this field to energy and the study of
astrophysical systems, and has urged the formation of a coherent
programmatic home in the Federal R&D portfolio. To this end, the Office
of Fusion Energy Sciences is now collaborating with NNSA in launching a
research program in this branch of science for the sake of advancing
both fusion energy science and the science of these extraordinary
systems so as to further understanding of our universe.
Importantly, the U.S. fusion energy sciences program also has
ambitions to develop and advance general plasma science in the broadest
sense. A number of vigorous university-based programs are deployed
across the country. Furthermore, my office supports over 30 joint
research efforts with the National Science Foundation to advance
general plasma science that extends beyond the immediate needs of the
fusion goal. This science can be of high import in describing natural
plasma phenomena and also has an impact on the economics of industrial
plasma applications. Joint research centers with university-scale
experiments are at the heart of these ventures and on shedding light on
the phenomena governing plasma dynamics in settings ranging from the
industrial to the solar corona.
The Office of Fusion Energy Sciences is currently engaged in a
formal strategic planning process aimed at filling scientific gaps in
the global research portfolio so as to assert U.S. leadership and
maximize U.S. scientific return where it best advances fusion as a
whole. For magnetic fusion, a Fusion Energy Sciences Advisory Committee
recently identified gaps in scientific knowledge that must be filled so
as to maximize ITER's scientific opportunities and to close the gaps
between ITER and demonstrating fusion power on the grid. This formal
gaps and priorities analysis was followed by a community-based activity
that identified the research needs for making such an advance. This
Office is developing a strategy by drawing upon this input and
assessing strategic opportunities for partnership across the Department
of Energy. Based on this input, the scientific challenges for magnetic
fusion can be broadly stated as follows:
(1) Understanding and optimizing the burning plasma state.
Experiments, theory, and simulation have significantly advanced
our understanding of what to expect from a burning plasma, and
will continue to do so. The U.S. domestic program will continue
to play a strong and world-leading role in preparing for the
burning plasma era. But ITER provides the only platform planned
to directly test and thus expand and challenge our
understanding of this complex physics. Both before and during
experiments on ITER, we must strengthen the coupling between
experiment, theory, and large-scale computer simulation so as
to enable prediction of burning plasma performance beyond
ITER's operating range and configuration.
(2) Understanding the requirements for extending the burning
plasma state to long times--days, weeks, and longer. Many
aspects of this are pursued in the U.S., and the second ten
years of ITER's operation will put our understanding to crucial
tests. However, in the next ten years overseas fusion programs
are set to assert a stronger role and leadership in part
through new billion dollar class research facilities in Europe,
Japan, South Korea, and China. We are exploring growing our
collaborations to increase their impact and the knowledge
returned. And finally,
(3) Advancing the materials science for enduring the harsh
fusion plasma environment, for extracting energy, and for
generating fusion fuel in situ. We are beginning to outline our
plans in these areas and to explore alignments with other
energy-related fields in developing a materials and fusion
nuclear science program. Common interests in materials research
exist across both magnetic and inertial confinement fusion
research. Beyond this, we will be exploring synergies in this
area between fusion, fission, and defense-related research so
as to assess the viability and requirements for a cross-office
``Materials for Energy'' effort that would make the most out of
common needs and diverse resources.
Concluding Remarks
In the next ten years, the U.S. fusion research program will strive
to be at the forefront of the burning plasma age, one in which research
students grow a strong connection to fusion's future and potential. It
will be an age where more is asked of advanced computation than ever,
where computer simulations are relied upon to close the gaps between
one research step and another, and reduce project costs and increase
confidence. It will be an era where single purpose laboratories
interact readily with multipurpose laboratories with common incentives
and common purpose of advancing energy-related science for all. It will
be an era in which the best combination of scientific depth and
richness is combined with the highest sense of urgency to help the
world address its energy challenges successfully to improve our quality
of life.
Thank you, Mr. Chairman, for providing this opportunity to discuss
the Fusion Energy Sciences Program at the Department of Energy. This
concludes my testimony, and I would be pleased to answer any questions
you may have.
Biography for Edmund J. Synakowski
Dr. Edmund J. Synakowski is the Associate Director of Fusion Energy
Sciences at the U.S. Department of Energy (DOE). With an annual budget
of over $400 million, the Office of Fusion Energy Sciences is the
federal office supporting research to develop the scientific basis for
fusion energy, and serves as a steward for plasma science. He joined
the Office of Science on June of 2009 from the Lawrence Livermore
National Laboratory where he was director of the Fusion Energy Program
and Deputy Division Leader for the Physics Division of the Physics and
Life Sciences Directorate. From 1988 through 2005, he was at the
Princeton Plasma Physics Laboratory where he was Head of Research and
Deputy Program Leader of the National Spherical Torus Experiment. He
also performed extensive research and led research programs in fusion
plasma confinement and control on the Tokamak Fusion Test Reactor. His
service to the fusion community has included participation in the
development of the initial research plan for the international ITER
research program, chairmanship of the U.S. Transport Task Force, and
membership of the American Physical Society Division of Plasma Physics
Executive Committee. Dr. Synakowski received a B.A. degree in Physics
from the Johns Hopkins University in 1982, graduating with Departmental
Honors and receiving the Donald Kerr Medal for excellence in physics.
He received a Ph.D. degree in physics from the University of Texas in
1988. He is a Fellow of the American Physical Society and received the
American Physical Society award for Excellence in Plasma Physics
Research in 2001 and the 2000 Kaul Foundation Prize for Excellence in
Plasma Physics Research and Technology Development from Princeton
University. He has published over 150 papers in the study of fusion
plasmas and has performed research on all of the major U.S. fusion
experiments.
Chairman Gordon. [Presiding] Dr. Prager, you are
recognized.
STATEMENT OF DR. STEWART C. PRAGER, DIRECTOR, PRINCETON PLASMA
PHYSICS LABORATORY
Dr. Prager. Well, thank you very much, Members of the
Committee, for this opportunity to discuss fusion energy, and
thank you, Congressman Holt, for the kind opening words and for
your deep engagement and expertise in this topic. As he said, I
am Director of the Princeton Plasma Physics Laboratory, which
is a DOE national lab managed by Princeton University dedicated
to developing fusion energy.
There are two complementary approaches to fusion; in one,
as you have heard, powerful lasers compress a tiny pellet of
fuel, releasing fusion energy in a flash. The National Ignition
Facility will tremendously advance the physics for this
approach.
I am here to discuss the approach known as magnetic fusion,
in which the large, hot plasma is confined continuously by
powerful magnetic fields. As I hear you already well recognize,
fusion energy is one of the most challenging physics and
engineering quests ever undertaken. It will be key to solving
perhaps the most pressing problem confronting the world today:
the absence of sustainable energy.
By any metric, we are far along the road to commercial
fusion power. In the past 30 years we have progressed from
producing one watt of fusion power for one-thousandth of a
second to 15 million watts for seconds, and ITER will produce
500 million watts for 10 minutes and longer. Driving this
progress has been the development of an entirely new field of
science called plasma physics. Outside reviews continuously
laud the progress of fusion. The most recent National Academy
study notes remarkable progress in recent years. But my focus
today is the future, the remainder of the journey to fusion
power.
My comments are informed by the just-completed study by the
U.S. fusion community commissioned by DOE known as the ReNeW
Report. Two hundred fusion scientists undertook this one-year
study that identifies the remaining scientific issues to
resolve for fusion power. A fusion system consists of the hot
plasma core and the surrounding material structure. We are
ready to move forward on the two major challenges to better
control the plasma and to develop new materials. The two
problems are coupled since the plasma and the material
structure interact with each other. Our ability to control the
100-million-degree plasma core is quite amazing, yet we have
more work to do to sustain the plasma indefinitely and
controllably. The sophistication of plasma science now offers
new opportunities; for example, designs of magnetic
configurations are possible now that were nearly impossible
even to conceive 20 years ago. They are possible only with
modern computers. Building upon the foundation of the mainline
tokamak approach, these designs produce plasmas that persist
indefinitely and are so well controlled as to reduce the
severity of the materials challenge.
It is crucial that we establish a research program and
materials for fusion. Materials must be developed to withstand
the intense heat that emerges from the plasma. But full
solution of the materials challenge ultimately requires study
of materials in a true fusion environment with the intense flux
of neutrons that are produced in the fusion reactions. It is
time to lay the groundwork for such a facility, sometimes
called a ``fusion nuclear science facility,'' since it exposes
materials to a nuclear fusion environment. If this facility
were designed somewhat more aggressively, it could possibly
demonstrate net electricity production. Design studies are
required to identify the wisest next step in these directions.
The Princeton Plasma Physics Lab aims to solve a broad
range of fusion science challenges. Our core capabilities in
plasma physics enable us to attack crucial problems in the
fusion plasma and in materials exposed to the intense plasma
heat. The major experiment at our lab is laying the physics
basis for a fusion nuclear science facility, is advancing
fusion science broadly and is investigating novel material
boundaries. We are contributing to the design and fabrication
of ITER and are preparing for research in ITER. We hope to play
key roles in a fusion nuclear science facility which would not
be located at our laboratory, and we are developing plans to
realize experimentally, at our laboratory, the new study state
approaches to fusion energy that could prove so essential to
the feasibility of fusion.
When I began my research career, the United States was the
world leader in fusion with the best facilities, arguably the
most innovative programs. Scientists from the world over
flocked to our labs. Japan sent research teams to U.S.
facilities to learn the trade. An alarming reversal of that
flow of scientists is now underway. The United States has not
built a major nuclear fusion facility in decades. The rest of
the world is seizing the opportunities. Major facilities more
ambitious than anything in the United States are starting
operation or are under construction in China, Japan, South
Korea, Germany and France. Our effort has dwindled to a
fraction of that of Europe and Japan. The time is right for the
United States to reverse its slide. Opportunities such as we
are discussing today abound to restore the United States to
world leadership and move us aggressively toward carbon-free,
abundant fusion energy.
And I will just close by inviting all Members to please
visit our laboratory, which is a short train ride up the coast,
and with that, thank you very much.
[The prepared statement of Dr. Prager follows:]
Prepared Statement of Stewart C. Prager
Mr. Chairman and Members of the Committee, thank you for this
opportunity to discuss fusion energy.
I am Director of the Princeton Plasma Physics Laboratory--a
Department of Energy national lab, managed by Princeton University,
dedicated to developing the scientific foundation for fusion energy.
Prior to nine months ago, I was a practicing fusion plasma physicist at
the University of Wisconsin.
There are two complementary, compelling approaches to fusion
energy. In one, powerful lasers compress a tiny frozen pellet of fusion
fuel, releasing fusion energy in a billionth of a second. The
anticipated demonstration of ignition in the National Ignition Facility
will tremendously advance the physics basis for this approach.
I am here today to discuss the approach known as.magnetic fusion,
in which a large, hot plasma (the hot gas that makes up the sun) is
confined continuously by powerful magnetic fields. Fusion energy is
perhaps one of the most challenging physics and engineering quests ever
undertaken; its realization will be key to solving what is perhaps the
most pressing problem confronting the world today--the absence of
sustainable energy. By any measure, we are far along the road to
commercial fusion power. My goal today is to talk about the future: the
remainder of the journey to fusion energy.
My comments are informed by the just-completed study by the U.S.
fusion community, commissioned by DOE and known as the ReNeW report.
About 200 fusion scientists undertook this one-year study that
articulates the scientific issues yet to resolve for fusion power,
beyond those to be resolved in the landmark international ITER
experiment. A fusion system consists of the hot plasma core--the ``sun
on Earth''--in which fusion reactions occur, and the surrounding
material structure. We are ready to move forward to better control the
plasma and to develop new materials. The two problems are coupled in
that the plasma affects the materials and the material affects the
behavior of the plasma within.
Our ability to control the 100 million degree plasma core is quite
amazing. Yet, we have more work to do to sustain the fusion plasma
indefinitely and controllably. The sophistication of plasma science now
offers new opportunities for fusion. For example, new designs of
magnetic configurations are possible now that were nearly impossible
even to conceive twenty years ago. They are possible only with modern
computers, enabled by new principles in plasma physics. Building upon
the substantial experimental foundation of the mainline tokamak
approach, these cousins of the tokamak produce plasmas that persist
indefinitely and are so well controlled as to reduce the severity of
the materials challenges.
It is crucial that we establish a research program in materials for
fusion. Materials must be developed to withstand the intense heat that
emerges from the plasma. This requires a basic materials research
combined with materials studies in plasma experiments.
But full solution of the materials challenge ultimately requires
study of materials in a true fusion environment--with the intense flux
of neutrons that are produced in the fusion reactions. It is time to
lay the groundwork for such a U.S. facility, sometimes called a fusion
nuclear science facility since it provides study of materials in the
nuclear fusion environment. If this facility were designed somewhat
more aggressively--to produce net fusion power as well as neutrons, it
would demonstrate electricity production. Design studies are required
to identify the wisest next step in these directions, considering our
level of physics and engineering readiness.
The Princeton Plasma Physics Lab is dedicated to solving the broad
range of fusion science challenges. Our key capability in plasma
physics enables us to attack crucial problems in the fusion plasma
core, the interaction between the plasma and materials, and the
properties of materials exposed to the intense plasma heat.
The major experiment at our lab is developing the plasma physics
basis for a fusion nuclear science facility, advancing physics broadly
applicable to fusion and ITER, and investigating novel materials
boundaries. We hope to play a key role in the physics and engineering
design of a fusion nuclear science facility, which would not be located
at our laboratory. We will continue our contributions to the design of
ITER, and are preparing ourselves for participation in ITER research.
And we are developing plans to realize experimentally, at our
laboratory, the new steady-state approaches to fusion energy that could
prove so essential to the feasibility of fusion.
When I began my research career the U.S. was the world leader in
fusion. We had the best facilities and arguably the most innovative
program. Scientists the world over flocked to our labs. The Japanese
government sent research teams to then-modern U.S. facilities to learn
the trade. An alarming reversal of that flow of scientists is now
underway. The U.S. has not built a major new fusion facility in
decades. The rest of the world is seizing the opportunities. Major
facilities, more ambitious than anything in the U.S., are starting
operation or are under construction in China, Japan, South Korea,
Germany and France. The U.S. effort has dwindled to a fraction of that
of the European Union and Japan. The time is ripe for the U.S. to
reverse its slide. Opportunities abound to restore the U.S. to world
leadership and move us aggressively toward carbon-free, abundant fusion
energy.
Appendix I
Executive Summary of the
Research Needs Workshop (ReNeW)
for Magnetic Fusion Energy Science
Nuclear fusion--the process that powers the sun--offers an
environmentally benign, intrinsically safe energy source with an
abundant supply of low-cost fuel. It is the focus of an international
research program, including the ITER fusion collaboration, which
involves seven parties representing half the world's population. The
realization of fusion power would change the economics and ecology of
energy production as profoundly as petroleum exploitation did two
centuries ago.
The 21st century finds fusion research in a transformed landscape.
The worldwide fusion community broadly agrees that the science has
advanced to the point where an aggressive action plan, aimed at the
remaining barriers to practical fusion energy, is warranted. At the
same time, and largely because of its scientific advance, the program
faces new challenges; above all it is challenged to demonstrate the
timeliness of its promised benefits.
In response to this changed landscape, the Office of Fusion Energy
Sciences (OFES) in the U.S. Department of Energy commissioned a number
of community-based studies of the key scientific and technical foci of
magnetic fusion research. The Research Needs Workshop (ReNeW) for
Magnetic Fusion Energy Science is a capstone to these studies. In the
context of magnetic fusion energy, ReNeW surveyed the issues identified
in previous studies, and used them as a starting point to define and
characterize the research activities that the advance of fusion as a
practical energy source will require. Thus, ReNeW's task was to
identify (1) the scientific and technological research frontiers of the
fusion program, and, especially, (2) a set of activities that will most
effectively advance those frontiers. (Note that ReNeW was not charged
with developing a strategic plan or timeline for the implementation of
fusion power.)
The Workshop Report
This Report presents a portfolio of research activities for U.S.
research in magnetic fusion for the next two decades. It is intended to
provide a strategic framework for realizing practical fusion energy.
The portfolio is the product of ten months of fusion-community study
and discussion, culminating in a Workshop held in Bethesda, Maryland,
from June 8 to June 12, 2009. The Workshop involved some 200 scientists
from Universities, National Laboratories and private industry,
including several scientists from outside the U.S.
Largely following the Basic Research Needs model established by the
Office of Basic Energy Sciences (BES), the Report presents a collection
of discrete research activities, here called ``thrusts.'' Each thrust
is based on an explicitly identified question, or coherent set of
questions, on the frontier of fusion science. It presents a strategy to
find the needed answers, combining the necessary intellectual and
hardware tools, experimental facilities, and computational resources
into an integrated, focused program. The thrusts should be viewed as
building blocks for a fusion program plan whose overall structure will
be developed by OFES, using whatever additional community input it
requests.
Part I of the Report reviews the issues identified in previous
fusion-community studies, which systematically identified the key
research issues and described them in considerable detail. It then
considers in some detail the scientific and technical means that can be
used to address these issues. It ends by showing how these various
research requirements are organized into a set of eighteen thrusts.
Part II presents a detailed and self-contained discussion of each
thrust, including the goals, required facilities and tools for each.
This Executive Summary focuses on a survey of the ReNeW thrusts.
The following brief review of fusion science is intended to provide
context for that survey. A more detailed discussion of fusion science
can be found in an Appendix to the Report, entitled ``Fusion Primer.''
Fusion science
Fusion's promise
The main advantages of producing power from fusion reactions are
well known:
Essentially inexhaustible, low-cost fuel, available
worldwide.
High energy-density of fuel, allowing straightforward
base-load power production without major transportation costs.
No production of greenhouse gas, soot or acid rain.
No possibility of runaway reaction or meltdown that
could pose a risk to public safety.
Minimal proliferation risk.
Only short-lived radioactive wastes.
Few of these benefits are unique to fusion; what is exceptional is
their simultaneous achievement in a single concept. For example,
fusion's freedom from greenhouse gas production and chemical pollution
is shared with, among other energy sources, fission nuclear power; in
this regard the relatively mild radioactivity of fusion, whose waste is
thousands of times less radioactive and long-lived than fission, is
significant. On the other hand, compared to the non-proliferating
renewable energy sources, fusion offers a steady, predictable energy
source with low land use.
To be weighed against these advantages is the long and relatively
expensive development path for fusion. Achieving the conditions
necessary for appreciable fusion reactions to occur invokes substantial
physics and engineering challenges. Yet the impressive progress
achieved in addressing these hurdles must be acknowledged. One measure
is the exponential increase in fusion power produced in laboratory
experiments, amounting to some eight orders of magnitude (a factor of
100,000,000) since the mid-1970's. Indeed some fusion experiments have
approached scientific ``break-even,'' producing roughly as much fusion
power as was externally supplied for heating the fuel. A more important
if less easily measured avenue of progress lies in scientific
understanding. Fusion scientists have developed a broad and
sophisticated, if still incomplete, picture of what is happening in a
magnetically confined fusion plasma. This advance now allows routine
control of key plasma properties and behavior.
Magnetic confinement
Magnetic confinement (more accurately termed ``magnetic
insulation'') allows the fusion fuel, which is necessarily in the form
of ionized gas, or plasma, to retain sufficient heat to maintain fusion
reactions. It acts by enforcing a relatively low plasma density at the
plasma boundary, where vessel walls would otherwise cool the gas, and
by inhibiting heat flow from the interior to the wall region. The
essential ingredient is a magnetic geometry in which the magnetic field
lines abide in a closed, bounded region.
During the last decades of the twentieth century, fusion research
gained important scientific victories in plasma confinement: major
advances in both the control of instability and the amelioration of
heat transport. While significant confinement issues remain to be
solved, and while most of the fusion scientific community looks forward
to substantial further improvements, the present demonstrated level of
confinement is sufficient to impart confidence in the future of fusion
energy. One indicator of this scientific advance is the rapid
confinement progress mentioned above. Perhaps a more significant
consequence is the decision by the international fusion community to
embark on the ITER project.
Breadth of fusion research
Fusion progress requires scientific research of the highest quality
and originality. Such science is not an activity to be balanced against
the energy goal, but rather an essential component of the quest for
that goal. This Report emphasizes the goal-directed nature of the
program, but it is also appropriate to mention that, like any deep
investigation, fusion research has enjoyed broad connections with other
domains of science.
Many connections are mentioned in the Theme chapters of Part I.
Examples are:
gyrokinetic simulation, used to understand transport
and stability in magnetized fusion plasmas, has become an
important tool in astrophysics and magnetosphere physics;
magnetic reconnection, a key phenomenon in the
stability of magnetically confined plasmas, has central
importance in numerous solar, magnetosphere and astrophysical
contexts;
turbulent heat transport across the magnetic field,
which plays a role in modern fusion experiments very similar to
its role in the equilibrium configuration of the sun and other
stars;
unstable Alfven waves, whose effects in fusion
experiments are closely similar to observed perturbations in
the Earth's magnetosphere;
the high-strength, ductile materials being developed
for fusion should have wide application in industry, including
aerospace and chemical manufacturing.
Research requirements
In the next two decades, the ``ITER era,'' magnetic fusion will for
the first time explore the burning plasma regime, where the plasma
energy is sustained mostly by its own fusion reactions. We expect ITER
to expand our understanding of fusion plasma science and to be a major
step toward practical fusion energy. It will also, as the first burning
plasma experiment, pose new requirements, including advanced
diagnostics for measurement and control in a burning-plasma
environment, and analytical tools for understanding the physics of
self-heating.
To benefit fully from its investment in ITER the U.S. must maintain
a broad research program, attacking fusion's scientific and technical
issues on several fronts. We need in particular to acquire knowledge
that ITER cannot provide: how to control a burning plasma with high
efficiency for indefinite periods of time; how to keep a continuously
burning plasma from damaging its surrounding walls--and the walls from
contaminating the plasma; how to extract the fusion energy from a
burning plasma efficiently and use it to produce electricity and a
sustained supply of tritium fuel; and ultimately how to design
economical fusion power plants. These requirements motivate a multi-
disciplinary research program spanning such diverse fields as plasma
physics and material science, and advancing a range of technologies
including plasma diagnostics, magnets, radio-frequency and microwave
sources and systems, controls, and computer simulation.
The key scientific and technical research areas whose development
would have a major effect on progress toward fusion energy production
were systematically identified, categorized and described in the three
resource documents that form the starting point for ReNeW: the report
of the Priorities, Gaps and Opportunities Panel, chaired by Martin
Greenwald; the report of the Toroidal Alternates Panel, chaired by
David Hill; and the report of the Energy Policy Act task group of the
U.S. Burning Plasma Organization.
In Part I of the ReNeW Report the full panoply of fusion issues are
summarized, and then examined from the point of view of research
requirements: the facilities, tools and research programs that are
needed to address each. The research thrusts presented in Part 11 are
essentially integrated combinations of these research requirements.
[NOTE: This paragraph is similar to the first paragraph on page 2.]
The ReNeW thrusts: a research portfolio
Thrust definition
The ReNeW thrusts listed below are the key results of the Workshop.
They constitute eighteen concerted research actions to address the
scientific and technological frontiers of fusion research. Each thrust
attacks a related set of fusion science issues, using a combination of
new and existing tools, in an integrated manner. In this sense each
thrust attempts a certain stand-alone integrity.
Yet the thrusts are linked, both by scientific commonality and by
mutual dependence. The most important linkages--for example,
requirements that a certain thrust be pursued and at least in part
accomplished before another is initiated--are discussed in Part 11 of
the main Report. Here we emphasize that fusion advances along a broad
scientific and technological front, in which each thrust plays an
important role.
The thrusts span a wide range of sizes, from relatively focused
activities to much larger, broadly encompassing efforts. This spectrum
is expected to enhance the flexibility of OFES planning.
ReNeW participants consider all the thrusts to be realistic: their
objectives can be achieved if attacked with sufficient vigor and
commitment. Three additional elements characterize, in varying degrees,
the ReNeW thrusts:
Advancement in fundamental science and technology--
such as the development of broadly applicable theoretical and
simulation tools, or frontier studies in materials physics.
Confrontation with critical fusion challenges--such
as plasma-wall interactions, or the control of transient plasma
events.
The potential for major transformation of the
program--such as altering the vision of a future fusion
reactor, or shortening the time scale for fusion's realization.
Thrust organization
The resource documents used by ReNeW organized the issues into five
scientific and technical research areas. Correspondingly, the ReNeW
organizational structure was based on five Themes, each being further
sub-divided into three to seven panels. The thrusts range in content
over all the issues delineated in the five Themes.
Many of the ReNeW thrusts address issues from more than one Theme.
For this reason the scientists contributing to most thrusts are from a
variety of research areas, and key elements of a given thrust may stem
from ideas developed in several Themes. In other words, the content of
a typical thrust transcends that of any single Theme. Nonetheless, it
is convenient to classify each thrust according to the Theme that
contains its most central issues.
The ReNeW thrusts are:
Theme 1: Burning plasmas in ITER.
ITER participation will be a major focus of U.S. fusion research
during the time period considered by ReNeW. The opportunities and
challenges associated with the ITER project are treated in Theme 1.
Thrust 1: Develop measurement techniques to understand and
control burning plasmas. This thrust would develop new and
improved diagnostic methods for measuring and controlling key
aspects of burning plasmas. The desired measurement techniques
must be robust in the hostile burning-plasma environment and
provide reliable information for long time periods. While
initially focused on providing critical measurements for ITER,
measurement capability would also be developed for steady-state
burning plasmas beyond ITER.
Thrust 2: Control transient events in burning plasmas. This
thrust would develop the scientific understanding and technical
capability to predict and avoid disruptions and to mitigate
their consequences, in particular for ITER. Also, tools would
be developed to control edge plasma transport and stability, to
minimize instability-driven heat impulses to the first wall.
Thrust 3: Understand the role of alpha particles in burning
plasmas. Key actions would be developing diagnostics to measure
alpha particle properties and alpha-induced fluctuations,
incorporating validated theories for alpha particle behavior
into integrated burning-plasma simulation tools, and expanding
the operating regime of burning plasma devices through the
development of control techniques for alpha-driven
instabilities.
Thrust 4: Qualify operational scenarios and the supporting
physics basis for ITER. This thrust would address key issues in
forming, heating, sustaining, and operating the high-
temperature plasmas required for ITER's mission. An integrated
research campaign would investigate burning-plasma-relevant
conditions with the use of upgraded tools for heating and
current drive, particle control and fueling, and heat flux
mitigation on existing tokamaks, along with a possible new
facility.
Theme 2: Creating predictable, high-performance, steady-state plasmas
An economic fusion reactor will require a steady state with higher
fusion density and greater fraction of self-heating than ITER. This
Theme addresses a broad range of issues, including both plasma physics
and engineering science, needed to demonstrate that plasmas with the
needed conditions can be achieved and controlled. Predictive capability
to enable confident extrapolation to a demonstration reactor is
emphasized.
Thrust 5: Expand the limits for controlling and sustaining
fusion plasmas. This thrust would integrate development of the
diagnostic, auxiliary heating, current drive, fueling systems
and control systems needed to maintain the nonlinear tokamak
plasma state, seeking to maximize performance. The thrust will
exploit existing experiments to test and develop new ideas and
proceed with increased integration in upcoming steady-state
experiments and alpha-heated plasmas in ITER, ultimately
enabling the self-heated and self-driven plasmas needed for a
fusion power plant.
Thrust 6: Develop predictive models for fusion plasmas,
supported by theory and challenged with experimental
measurement. Advances in plasma theory and simulation would be
combined with innovative diagnostic methods and experiments to
improve and validate models of confined plasma dynamics.
Assessment of critical model elements would be provided by
dedicated analysts, acting as bridges between theorists, code
developers and experimentalists.
Thrust 7: Exploit high temperature superconductors and other
magnet innovations to advance fusion research. Magnets are
crucial for all MFE concepts. This focused thrust would perform
the research necessary to enable revolutionary new high
temperature superconducting materials to be used in fusion
applications. Key activities include development of high-
current conductors and cables, and integration into components
of fusion research experiments, with great potential to improve
their design options.
Thrust 8: Understand the highly integrated dynamics of
dominantly self-heated and self-sustained burning plasmas. This
thrust would explore scenarios where, as in a reactor, most
heat comes from fusion alphas and most current is self-driven
by plasma gradients. It would start by assessing potential
advanced plasma scenarios and upgrades on ITER which could
enhance its performance. In parallel, scoping/design studies
would be done for a new US facility to explore the high fusion
gain DEMO plasma regime. The studies would support actions to
proceed with ITER enhancements, the construction of a U.S. D-T
facility, or both.
Theme 3: Taming the plasma-material interface
Magnetic confinement sharply reduces the contact between the plasma
and the vessel walls, but such contact cannot be entirely eliminated.
Advanced wall materials and magnetic field structures that can prevent
both rapid wall erosion and plasma contamination are studied in Theme
3.
Thrust 9: Unfold the physics of boundary layer plasmas.
Comprehensive new diagnostics would be deployed in present
confinement devices to measure key plasma parameters in the
boundary region, including densities and temperatures,
radiation, flow speeds, electric fields and turbulence levels.
The results could vastly improve numerical simulation of the
edge region, allowing, in particular, reliable prediction of
wall erosion and better radio-frequency antenna design.
Thrust 10: Decode and advance the science and technology of
plasma-surface interactions. Measurement of complex interaction
of plasma with material surfaces under precisely controlled and
well-diagnosed conditions would provide the information needed
to develop comprehensive models to uncover the basic physics.
These measurements would be made on both upgraded present
facilities and new boundary plasma simulators capable of
testing irradiated and toxic materials.
Thrust 11: Improve power handling through engineering
innovation. Heat removal capability would be advanced by
innovative refractory power-exhaust components, in parallel
with assessment of alternative liquid-metal schemes. Materials
research would provide ductile, reduced-activation refractory
alloys, which would be developed into prototypes for
qualification in high-heat flux test devices. Practical
components would be deployed on existing or new fusion
facilities.
Thrust 12: Demonstrate an integrated solution for plasma-
material interfaces compatible with an optimized core plasma.
Understanding of interactions between a fusion plasma core
region and its boundary would be advanced and validated in a
new facility. The facility would combine high power density,
long pulse length, elevated wall temperature and flexibility
regarding boundary systems, in a limited-activation
environment. Knowledge gained from thrusts 9-11 would help
guide the design of this facility.
Theme 4: Harnessing fusion power
Fusion energy from D-T reactions appears in the form of very
energetic neutrons. Theme 4 is concerned with the means of capturing
this energy, while simultaneously breeding the tritium atoms needed to
maintain the reaction.
Thrust 13: Establish the science and technology for fusion
power extraction and tritium sustainability. Fusion must create
the tritium fuel it uses, and do so in the same systems that
capture and extract the fusion energy. This thrust develops the
scientific foundation and engineering of practical, safe and
reliable processes and components that harvest the heat, create
and extract the tritium, and rapidly process and contain the
tritium. The thrust will culminate in a fuel and power handling
capability on a scale needed for a demonstration energy system.
Thrust 14: Develop the material science and technology needed
to harness fusion power. The objective of this thrust is to
create low-activation, high-performance materials that
effectively function for a long time in the hostile fusion
environment. An essential requirement to fulfill the mission of
this thrust is the establishment of a fusion-relevant neutron
source to perform accelerated characterization of the effects
of radiation damage to materials.
Thrust 15: Create integrated designs and models for attractive
fusion power systems. Advanced design studies focused primarily
on DEMO, but also on nearer term fusion nuclear facilities is
one element of this thrust. These would lay out the scientific
basis for fusion power and provide focus to the research
efforts required to close the knowledge gap to DEMO. The other
element comprises science-based predictive modeling
capabilities for plasma chamber components and related systems.
Theme 5: Optimizing the magnetic configuration
Currently most large fusion experimental devices are based on the
tokamak magnetic configuration, a design using a strong, axisymmetric
external magnetic field to achieve operating parameters close to those
in a fusion reactor. Alternative magnetic configurations are studied to
investigate physics and technology principles that could optimize the
design of future fusion devices. The most developed alternate toroidal
magnetic configurations are considered in Theme 5.
Thrust 16: Develop the spherical torus to advance fusion
nuclear science. Experiments on the small aspect-ratio tokamak,
or Spherical Torus, would be extended to regimes of lower
collision frequency, approaching values needed for fusion
nuclear science applications. Plasma start-up, power handling,
controlled stability, and sustainment issues in this regime
would be studied in long-pulse experiments using stronger
magnetic fields, improved heating and current drive, and
advanced diagnostics, with strong coupling to theory and
modeling.
Thrust 17: Optimize steady-state, disruption-free toroidal
confinement using 3-D magnetic shaping, and emphasizing quasi-
symmetry principles. Magnetic quasi-symmetry in 3-D
configurations is expected to lead to excellent plasma
confinement while ensuring stable steady-state burning plasma
performance with minimal need for control. This thrust would
conduct new quasi-symmetric experiments, which would, together
with theory, engineering design, and targeted international
collaboration, validate extrapolation to burning plasma
applications.
Thrust 18: Achieve high-performance toroidal confinement using
minimal externally applied magnetic field. This thrust advances
a multi-faceted program of theory, simulation, and well-
diagnosed experiments to resolve critical issues of
confinement, stability, and current sustainment in magnetic
configurations with minimal toroidal field. New devices with
heating and current drive systems would enable scaling to high
temperature and small ion gyroradius. Fusion system studies
will guide productive directions for present and future
research.
Appendix:
A Fusion Primer
Just as the heaviest elements, such as uranium, release energy when
fission allows them to become smaller, so the very lightest elements
release energy when they fuse, joining together to produce larger
nuclei. (The dividing line between nuclei that are too light and want
to fuse and those that are too heavy occurs at iron, the most stable
nucleus.) The reaction that occurs most readily is the fusion of two
isotopes of hydrogen: deuterium (D), whose nucleus consists of a proton
and a neutron, and tritium (T), whose nucleus contains a proton and two
neutrons. Fusion of these nuclei--the so-called D-T reaction--yields
helium, an inert, non-radioactive gas whose nucleus has two protons and
two neutrons. This helium nucleus or ``alpha particle'' carries 20
percent of the fusion energy production. It is contained by magnetic
fields, and provides the plasma self-heating that sustains the very
high plasma temperature. The remaining neutron is released at very high
energy--energy whose capture provides 80 percent of the energetic
profit of the reaction.
A reactor based on D-T reactions would have to breed tritium from
lithium (which is plentiful), using the neutrons liberated in the D-T
fusion process. More advanced fuel cycles would not require tritium
breeding, but the D-T reaction has advantages with regard to
accessibility and energy production. It is expected to be used in at
least the first generation of fusion power reactors.
Because all nuclei are positively charged, they electrically repel
each other. This ``Coulomb repulsion'' can be overcome only by bringing
the reactants to very high temperatures; in the case of D-T the
required temperature exceeds one hundred million degrees.
Far below thermonuclear temperatures the electron on each hydrogen
atom breaks free from its nucleus, yielding independent ion and
electron fluids. The resulting electrically active gas, called plasma,
can carry enormous electric currents; it is strongly responsive to
electromagnetic fields, while at the same time able to produce strong
fields on its own. Thus the operating fluid in any fusion device is
plasma, a form of matter more electro-dynamically active than any
conventional liquid, solid or gas.
In summary, the key features of D-T fusion are:
1. an operating temperature in the hundred-million degree
range, with the result that the working gas is necessarily in
the plasma state;
2. an energy release primarily in the form of very fast alpha
particles and neutrons, whose energy must be captured to
provide the thermal output of the reactor;
3. the need to breed tritium from the D-T neutron and lithium.
Heating and confinement
Evidently the most basic tasks in constructing a fusion reactor are
to heat a hydrogen gas to thermonuclear temperatures, and then to
confine the resulting plasma for a time long enough for fusion
reactions to take place, thus maintaining the high temperature. In most
reactor designs heating is provided by a combination of driving
electric currents through the plasma, directing energetic particle
beams at the plasma, and energizing plasma particles by means of radio-
frequency electromagnetic radiation, similar to the heating mechanism
of a microwave oven.
Confinement is measured by the so-called energy confinement time,
denoted by tE. Since both reaction rates and energy loss rates depend
upon the plasma density n, the required value of tE depends on plasma
density. It turns out that the critical parameter is the product ntE;
when density is measured in ions per cubic centimeter and tE in
seconds, sufficient confinement has been achieved if the product
exceeds about 1014 sec/cm3 (the ``Lawson
criterion''). [NOTE: This paragraph is a little technical for a general
primer, but it seems to work.]
One way to satisfy the Lawson criterion is to compress a hydrogen
pellet to extreme density values, exceeding the density of conventional
solids, while allowing relatively short confinement times. This is the
approach taken by the inertial confinement program. The main arm of
international fusion research uses much lower densities-lower even than
the density of air at the Earth's surface. Thus the working fluid is a
rarefied plasma, whose low density is part of the reason for the
intrinsic safety of the device. The relatively long confinement time
thereby required is supplied by magnetic fields, taking advantage of
the plasma's strong response to such fields. This line of research is
called magnetic fusion, although the phrase ``magnetic confinement for
fusion'' would be more descriptive.
Magnetic confinement
Neon signs confine cold plasma in glass tubes. But a very hot,
rarefied plasma--a fusion plasma--could not maintain thermonuclear
temperatures if it had substantial contact with a material wall. At the
densities used in magnetic fusion, plasma resting against a wall will
quickly cool, bringing fusion reactions to a halt. So the confining
magnetic field must protect the plasma from being quenched by contact
with its bounding vessel. A magnetic field configured to provide this
confinement is traditionally called a ``magnetic bottle.''
A magnetic bottle can work because charged particles--the ions and
electrons that constitute a fusion plasma--spiral around the local
field direction in helical orbits; the stronger the field, the tighter
the helix. Thus, while motion parallel to the field is unaffected,
motion perpendicular to the local field direction is strongly
inhibited.
This inhibition of perpendicular motion has two effects. First, it
allows the magnetic force to act against plasma pressure, pushing
plasma away from the vessel wall. This profile control is especially
effective when a divertor--a magnetic geometry in which the outermost
field lines are diverted into an external chamber--is employed. In this
case the layer of plasma near the vessel wall has especially low
density, imposing a near vacuum between the inner plasma core and the
wall.
The second insulating effect of the magnetic field pertains to
dissipative transport. The inhibition of perpendicular motion affects
plasma diffusion and heat conduction: transport in directions
transverse to the field is sharply reduced, while transport parallel to
the field is unaffected. For an appropriate field configuration this
anisotropy markedly slows the conduction of heat from the fusion plasma
core to the boundary region. Notice that this effect acts throughout
the plasma volume, not only near the wall.
It is significant that while a magnetic bottle can reduce plasma
contact with material boundaries, such contact is not eliminated. The
residual contact is sufficiently tenuous to maintain a hot plasma
interior, but still problematic because the wall material can be
scarred. Aside from the obvious lifetime aspects of such erosion,
plasma-wall interaction can allow impurities from the wall to enter the
confinement region, with deleterious effects on both confinement and
fusion reaction rates. Thus, significant materials-physics issues arise
in the fusion quest.
A centuries-old theorem in topology shows that any closed surface
on which the magnetic field does not vanish must have the topology of a
torus: a magnetic bottle must be toroidal--donut-shaped. All the
devices consider by ReNeW resemble donuts in this sense. (So-called
``magnetic mirrors'' get around the topological theorem by ``plugging''
the ends of a cylindrical field configuration; the mirror approach to
confinement was not part of the purview of this ReNeW.) Since the only
source of a magnetic field is electric current, magnetic confinement is
based on electric currents flowing around or within some toroidal
surface.
Most confinement devices employ a combination of external currents,
in wire-wound coils, and internal currents, flowing within the plasma
itself, to maintain the toroidal field structure. A prominent example
is the tokamak, in which external and internal currents combine to
yield a confining field that is symmetric with respect to a central
axis. Other confinement schemes have yet to achieve the tokamak's level
of performance but could bring operating advantages. For example, the
stellarator deliberately breaks the field symmetry in order to simplify
steady-state operation. And there are schemes under investigation that
require relatively weak (and therefore less expensive) external
magnetic fields.
Constructing a magnetic bottle does not solve the problem of
confinement; there are essentially two additional hurdles. First,
plasma currents, arising spontaneously from electromagnetic and fluid
instability, can create magnetic fields that open up the bottle.
Second, even when the magnetic configuration is stable with regard to
gross distortion, localized ``micro-instabilities'' can produce
fluctuations that degrade confinement. Common versions of such
accelerated transport resemble boiling water on a stove: the water
remains in the pot, but its turbulent motion rapidly conducts heat from
the hot bottom to the cooler upper surface.
In the last decades of the twentieth century fusion research gained
important scientific victories in plasma confinement: major advances in
both the control of instability and the amelioration of turbulent
transport. While significant confinement issues remain to be resolved,
and while the fusion scientific community looks forward to substantial
further improvements, the present demonstrated level of confinement is
sufficient to impart confidence in the future of magnetic fusion
energy.
Heating and confinement are the central, but not the only,
challenges that must be faced before fusion power can be realized. Even
a perfectly confined plasma at thermonuclear temperature must be fueled
with reactant, it must be promptly cleansed of the helium that fusion
produces, its thermal energy yield must be effectively retrieved, and
so on. Such challenges occupy increasing research attention as the
fusion program matures; they are the subject of major attention by
ReNeW.
Biography for Stewart C. Prager
Stewart Prager is Director of the Princeton Plasma Physics
Laboratory, a Department of Energy national laboratory, and Professor
of Astrophysical Sciences at Princeton University. He received his
Ph.D. degree in plasma physics from Columbia University in 1975.
Following two years performing fusion energy research at General
Atomics in San Diego he joined the University of Wisconsin Madison as
an Assistant Professor of physics. Prager remained at the University of
Wisconsin, as a Professor of physics, until 2009 when he assumed his
position at Princeton.
Prager's research focuses on basic plasma physics, including
applications to fusion energy and, more recently, applications to
astrophysics. He has worked to advance the understanding and control of
spontaneous plasma processes, such as turbulence, transport, and
processes characterized under the umbrella of magnetic self-
organization. While at Wisconsin, Prager was director of the Madison
Symmetric Torus (MST) experimental facility supported by DOE. He also
served as Director of the Center for Magnetic Self-Organization in
Laboratory and Astrophysical Plasmas, established through the National
Science Foundation program of ``physics frontier centers.''
Prager has participated in numerous scientific planning and
advisory processes, including service as the chair of the DOE's Fusion
Energy Sciences Advisory Committee, as Chair of the Division of Plasma
Physics of the American Physical Society (APS), and as President of the
University Fusion Association. He is also a co-recipient of the APS
Dawson Prize for Excellence in Plasma Physics, a fellow of the APS, and
a recipient of the Leadership Award of Fusion Power Associates.
Chairman Baird. Thank you.
Dr. Mason.
STATEMENT OF DR. THOMAS E. MASON, DIRECTOR, OAK RIDGE NATIONAL
LABORATORY
Dr. Mason. Mr. Chairman, Ranking Member Inglis and Members
of the Committee, thank you for the opportunity to appear
before you today. My name is Thom Mason. I am the Director of
the Department of Energy's Oak Ridge National Laboratory
(ORNL), and unlike the other members of the panel, I am not an
expert in fusion. But as Director of DOE'S largest multipurpose
laboratory, I oversee a broad program of energy-related R&D
that includes magnetic fusion, and it is from that perspective
that I see fusion research as an essential part of the Nation's
energy R&D portfolio.
You have heard how this is a promising source of energy
that uses widely available fuel and produces no greenhouse gas
emissions or long-lived radioactive waste. In fact, one could
say that the fuel for fusion is smart people and high-end
manufacturing, and so from that point of view, from the point
of view of U.S. competitiveness and the type of energy source
that is worth seeking, I think fusion is significant. Its
science and technology base is now mature enough to warrant a
significant investment in determining our readiness to advance
to a prototype fusion reactor.
ITER is an international project to demonstrate the
scientific and technological feasibility of fusion energy. It
is being built at Cadarache in France by seven partners: the
United States, Russia, the European Union, Japan, China, South
Korea and India. Each partner is responsible for a share of the
hardware, personnel and cash contributions towards common
expenses. This international partnership presents an
extraordinary number of technical and management challenges.
ITER will be twice the size of the largest existing fusion
experiment. It is a first-of-a-kind experimental facility made
up of a large number of complex systems provided by suppliers
all over the world and they must be integrated into a device
that can function under extremely demanding challenges. The
ITER organization has also faced the challenge of standing up
and staffing a new multinational organization to provide
coordination, project management, integration and engineering
while overseeing efforts to finalize the design and supervise
construction at Cadarache. Given these challenges, it is not
surprising that there have been some teething pains. For
example, in the United States we have struggled to secure
funding for ITER during some very tough budget years, but now
with the strong support provided by Congress in fiscal year
2009, for which we are very grateful, we are on a sound
footing.
Today the ITER organization has two urgent tasks:
completing the overall design and establishing realistic cost
and schedule baselines. The U.S. fusion community is fully
engaged in the execution of these tasks.
Oak Ridge has hosted and led the U.S. ITER project office
since 2006. We are responsible for all U.S. activities
supporting ITER construction. The estimated cost of these
activities is between $1.4 and $2.2 billion, so this is a heavy
responsibility and it is one that we take very seriously. The
office was located at Oak Ridge to take advantage of project
management expertise developed during the Spallation Neutron
Source project, which as you have heard was a $1.4 billion
neutron-scattering facility that was designed and built by a
partnership of six Department of Energy national laboratories.
It was completed on scope, on schedule and on budget in 2006.
We are working with other national laboratories, industry and
universities to deliver the U.S. contributions to ITER.
Recently, two contracts worth $34 million were awarded to
U.S. companies: one in Waterbury, Connecticut, and one in
Carteret, New Jersey. The New Jersey supplier has also received
a contract from the European Union's ITER domestic agency. This
speaks well of the ability of U.S. companies to compete
internationally for work supporting ITER. More than 160
companies and universities in 33 states have worked directly on
the project, and many others are interested in future
procurements. The U.S. ITER team also provides substantial
support to the international organization by developing systems
engineering procedures, technical baseline documents, project
management plans and so forth.
As ITER proceeds through construction into operation, Oak
Ridge will continue to play a substantial role in fusion and
the U.S. ITER project will remain a high priority. We will use
our distinctive capabilities in materials R&D, nuclear
technology and high-performance computing to advance fusion
science, technology and engineering.
One specific focus will be a next-generation fusion nuclear
science facility to answer questions that lie outside of ITER's
scope. Our strengths at Oak Ridge position us to lead the
technical and programmatic planning for this facility and we
will work with the U.S. community to bring it into being at an
appropriate pace.
ITER represents an opportunity for the DOE national
laboratories, U.S. universities and U.S. industry. We are now
positioned to make substantial contributions to ITER and to
reap the rewards it will provide in terms of increased
scientific knowledge, high-tech jobs that will help us rebuild
U.S. manufacturing capacity, and training for fusion scientists
and engineers who work on ITER and bring home what they learn.
A sustained investment in ITER is essential to realizing the
benefits of this extraordinary effort.
We also need a vibrant domestic fusion program to take
advantage of the knowledge gained from ITER and to continue
advancing toward commercial fusion power. ITER is a major step
forward, but it will not answer all of our questions.
Congresswoman Zoe Lofgren has introduced a bill calling for
a comprehensive plan to identify the R&D facilities needed to
ensure the realization of practical fusion energy, and this is
a vital step in setting the direction of the U.S. fusion
program. The bill also calls for investing in U.S. capability
in fusion engineering science. This will enable us to develop
the materials and enabling technology needed to realize the
full benefit of ITER and to take the next steps toward a fusion
demonstration facility.
Sustained support for fusion engineering science and
facilities is essential to successful development of this
future energy source. As we search for sustainable energy
solutions, we need a balanced R&D portfolio that includes both
near- to mid-term improvements in energy efficiency, renewables
and fission, along with electrification of our transportation
sector, and fusion as a source of clean, safe and abundant
baseload power in the long-term interest.
Thank you again for the opportunity to testify. I welcome
your questions on this important topic.
[The prepared statement of Dr. Mason follows:]
Prepared Statement of Thomas E. Mason
Mr. Chairman, Ranking Member Inglis, and Members of the Committee:
Thank you for the opportunity to appear before you today. My name is
Thomas E. Mason, and I am Director of the U.S. Department of Energy's
Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. It is an
honor to provide this testimony on the status of the ITER international
fusion project, the role of ORNL as the headquarters of the U.S. ITER
Project Office, and the way that fusion research fits into the overall
portfolio of research and development (R&D) at ORNL.
INTRODUCTION
ORNL is the Department of Energy's largest science and energy
laboratory. From my position as Director of a national laboratory with
research encompassing fundamental science of relevance to energy
through an extensive suite of energy programs--including energy
efficiency; energy from renewable, fossil, and fission sources; and
energy transmission and distribution--I view fusion as an essential
part of the Nation's R&D portfolio. Fusion is a promising long-term
source of energy whose fuel is widely available and whose emissions
would include neither CO2 nor long-lived radioactive waste.
Its scientific and technological basis is maturing and warrants a
significant federal investment, with the aim of advancing the
underlying science and gaining understanding of the technology
sufficient to enable future decisions on advancing to the level of a
prototype reactor.
ORNL has been engaged in research on fusion energy since the early
1950s, when the Atomic Energy Commission launched Project Sherwood with
the goal of developing a fusion analog to the fission reactor. From its
earliest days, the Oak Ridge fusion program has drawn on the diverse
resources afforded by ORNL's standing as a multi-program laboratory,
and it has leveraged substantial investments by the Department of
Energy in materials science, nuclear technology, and high-performance
computing to deliver advances in plasma theory and simulation, magnetic
confinement experiments, plasma heating and fueling, atomic physics,
and materials development.
As soon as magnetic fusion research was declassified in 1958, the
ORNL program initiated extensive collaborations with the international
fusion community, which continue today. In particular, ORNL has been a
key contributor to ITER since the inception of this activity in 1985.
The promise of fusion as a clean and abundant source of energy has
driven extensive programs of R&D, at ORNL and other institutions
throughout the world, for more than six decades. Impressive progress
has been made in overcoming the challenges of harnessing fusion energy.
From experiments in the United States and other nations, we have
established the scientific and technical knowledge base for fusion, and
we have reached a point at which the next step is to create a burning
plasma: that is, an ionized gas in which the alpha particles produced
by the fusion of hydrogen isotopes provide enough heat to keep the
fusion reaction going.
With the potential to provide clean baseload electrical energy
without a fuel resource constraint, fusion can be an important
component of a long-term shift away from fossil fuels with the
attendant environmental, economic, and national security benefits. The
main cost lies in the intellectual content and high-end manufacturing,
both of which are hallmarks of American industrial strength, so in
addition to providing an attractive solution to our energy needs,
fusion offers the potential to drive the development of a new industry.
THE ITER INTERNATIONAL FUSION PROJECT
The ITER international fusion project has been established to
construct an experimental device that will demonstrate the scientific
and technological feasibility of fusion energy and achieve sustained
fusion power generation. The long-range goal is for ITER to produce at
least ten times as much power as is needed to heat the plasma. It will
test many of the key technologies needed to use fusion as a practical
energy source, and it will provide industry with the opportunity to
validate production techniques for components needed for future fusion
power plants.
ITER will be constructed at Cadarache in southeastern France from
components fabricated in the countries of the ITER Members: the United
States, the Russian Federation, the European Union, Japan, the People's
Republic of China, South Korea, and India. A Joint Implementation
Agreement, finalized in 2007, governs the details of construction,
operation, and decommissioning, as well as financing, organization, and
staffing. Each ITER Member is responsible for supplying a share of
hardware (including supporting R&D and design); personnel assigned to
the ITER site; and cash contributions toward common expenses. The
international ITER Organization established by the Joint Implementation
Agreement is the legal entity responsible for project execution. It is
governed by a Council that includes senior U.S. Department of Energy
officials.
Each ITER Member was tasked with creating a Domestic Agency to
fulfill the Member's obligations under the ITER Joint Implementation
Agreement. The Domestic Agencies' role is to perform R&D and design and
to procure each Member's in-kind (i.e., non-cash) contributions to
ITER. The Domestic Agencies employ their own staff, have their own
budget, and place contracts with suppliers. The United States was the
first ITER Member to establish its Domestic Agency under the auspices
of the Office of Fusion Energy Sciences within DOE's Office of Science.
This is the U.S. ITER Project Office, about which I will speak further
in a moment.
Under the terms of the Joint Implementation Agreement, the United
States is a full Member of the ITER project. Our 9.09 percent share of
the total cost gives us access to all scientific data and the right to
propose and carry out experiments. It also creates opportunities for
U.S. industry to manufacture the high-technology components that make
up roughly 80 percent of our contribution.
The ITER project presents an extraordinary number of technical and
management challenges. Although the design of ITER is not yet complete,
it is expected to be twice the size of the largest existing fusion
experiment. It is a ``first-of-a-kind'' experimental facility
comprising a large number of systems, some of which require innovative
technologies. These systems, to be constructed by suppliers selected by
the seven Domestic Agencies, must be integrated to produce a system
that can perform under extremely demanding conditions.
The ITER Organization has also faced the challenge of standing up
and staffing a new organization to provide coordination, project
management, technical integration, and engineering while overseeing
efforts to finalize the ITER design and supervising early-stage civil
construction in Cadarache. A host of issues relating to finances,
communication, intellectual property rights, conflicting national
safety and import/export regulations, and other areas unique to this
large-scale, high-visibility multinational scientific collaboration
have had to be resolved to the satisfaction of all parties.
Given these challenges, it is not surprising that the project has
experienced some ``teething pains.'' We have not been immune to those
teething pains in the United States as we struggled to secure funding
during some very tough budget years; however, with the support provided
by Congress in FY 2009 we are now on a sound footing and able to fully
engage our international partners. The most urgent tasks facing the
international ITER Organization today are completing the overall ITER
design and systems engineering and establishing realistic schedule and
cost baselines. The U.S. fusion community is supporting these tasks,
while continuing to carry out an extensive program of work that is
enhancing the physics basis and technology support for ITER.
THE ROLE OF ORNL AS HEADQUARTERS OF THE U.S. ITER PROJECT OFFICE
Since 2006, ORNL has hosted and led the U.S. ITER Project Office,
which is responsible for project management of all U.S. activities to
support construction of ITER. The U.S. share of the international ITER
project construction has an estimated range of $1.4 billion to $2.2
billion, so this is a heavy responsibility and one that we at ORNL take
very seriously.
All U.S. ITER activities are managed by the Department of Energy's
Office of Science as a Major Item of Equipment (MIE) project and are
subject to rigorous review. The project team under ORNL includes
Princeton Plasma Physics Laboratory and Savannah River National
Laboratory as partner laboratories.
The U.S. ITER Project Office was located at Oak Ridge to take
advantage of the project management expertise developed during the
construction of the Spallation Neutron Source. This $1.4 billion
neutron scattering facility was designed and constructed by a
partnership of six Department of Energy national laboratories, which I
had the privilege of leading from 2001 to 2006. The project was
completed ahead of schedule and within budget in 2006, and many members
of the project team are now applying their expertise to the needs of
the U.S. ITER Project Office.
The U.S. ITER team is engaging other national laboratories and
industry and university partners across the United States in R&D,
engineering, manufacturing, and fabrication of the U.S. contributions
to ITER. Earlier this month, the U.S. ITER Project Office awarded two
contracts totaling $33.6 million, one to a company in Waterbury,
Connecticut, and the other to a company in Carteret, New Jersey, for
components of the superconducting magnets that will confine the ITER
plasma. It is noteworthy that in addition to these U.S.-funded
contracts, a similar award has been made to the New Jersey supplier by
the European Union's ITER Domestic Agency, which speaks well of the
ability of U.S. industry to compete in this area on the world stage. To
date, more than 160 companies and universities in 33 states have worked
directly on the project, and some 140 have expressed interest in future
procurements.
The U.S. ITER team is also providing substantial support to the
international ITER Organization. Staff have contributed to the
development of systems engineering procedures and technical baseline
documents, assisted in the development of project management processes
and procurement arrangements, and evaluated project risks and assisted
with development and implementation of risk mitigation plans.
FUSION ENERGY RESEARCH AT ORNL OVER THE NEXT 20 YEARS
As the ITER project moves through construction and operation, ORNL
will continue to play a substantial role, both through the U.S. ITER
Project Office and through an extensive and well-integrated program of
science, technology, and engineering aimed at supporting ITER and
developing the understanding required for an attractive fusion energy
source.
In particular, we will take advantage of ORNL's distinctive
capabilities in materials R&D, nuclear technology, and high-performance
computing to deliver the science and technology needed to realize the
full potential of ITER and to exploit the knowledge gained from it in
advancing toward a fusion power plant. Expertise in nuclear design and
operations, nuclear materials science, ITER, fusion engineering, and
project management positions ORNL to lead U.S. technical and
programmatic planning for a next-generation fusion nuclear science
facility. Such a facility and associated R&D programs could establish
the scientific basis for fusion fuel self-sufficiency and reliable and
efficient power extraction under realistic fusion power reactor
conditions.
CLOSING REMARKS
The international ITER project represents an opportunity for the
Department of Energy's national laboratories, U.S. universities, and
U.S. industry to play a key role in a very challenging technical
development and build a scientific and technical base for moving the
fusion program from a science experiment to an engineering
demonstration. The United States is positioned to make substantial
contributions to the international ITER project and to reap the rewards
that it will provide: increased scientific knowledge, high-technology
jobs that can contribute to the restoration of U.S. manufacturing
capacity, and training of fusion scientists and engineers who have the
opportunity to work on this experiment with their colleagues from other
nations and to apply the findings to the next generation of fusion
systems. Sustaining the U.S. investment in ITER is essential to
realizing the benefits of this extraordinary effort.
Our investment in ITER should be complemented by a vibrant domestic
fusion program to ensure that the United States is positioned to
exploit ITER for research, capitalize on the knowledge gained from
ITER, and move forward along the way to commercial fusion power. While
ITER represents a path-breaking advance toward the goal of practical
magnetic fusion energy, it cannot address all of the questions that
must be answered before we can proceed with a fusion power plant. For
example, ITER is based on a magnetic confinement concept known as the
tokamak, which was invented in Russia in the 1960s. This configuration
was selected for ITER because of its maturity, but other configurations
have properties that may make them attractive candidates for commercial
power plants. Other challenges that lie outside ITER's scope include
the development of materials and components that can withstand the
intense conditions at the edge of a burning plasma and handle prolonged
exposure to neutrons.
Legislation introduced by Congresswoman Zoe Lofgren, the Fusion
Engineering Science and Fusion Energy Planning Act of 2009 (H.R. 3177),
calls for the development of a comprehensive plan to identify what the
U.S. fusion community must do to ensure the realization of practical
fusion energy. This is a vital step in determining the direction of the
U.S. fusion program, and it has the full support of the program's
leadership.
Congresswoman Lofgren's bill also calls for a targeted investment
of $165 million over the next three years to enhance U.S. capability in
fusion engineering science, in addition to the funding provided to the
Department of Energy's Office of Fusion Energy Sciences for current
programs. This would provide the U.S. fusion community with resources
for developing the materials and enabling technology needed to realize
the full benefit of the ITER project and to prepare for the
experiments, such as a fusion nuclear science facility, needed to move
beyond ITER to a successful fusion demonstration facility.
Some might argue that the investment of substantial sums in fusion
R&D over the past six decades should have enabled us to reach the goal
of fusion energy by now. In response to such an argument, I would make
two points. First, controlled fusion has turned out to be a much more
challenging scientific and technological problem than was originally
thought. Optimistic predictions based on an incomplete understanding of
the difficulties involved have haunted the program in the past. Today,
however, we have attained a level of understanding that provides a
solid foundation for ITER and for continuing efforts to find ways of
meeting our energy needs with fusion.
Second, in 1972, federal funding for magnetic fusion energy was
$33.3 million (about $172 million in today's dollars); it rose
dramatically in response to the energy crisis, peaking in 1977 at
roughly $1 billion in today's dollars, and then declined precipitously,
to $230 million in 1997 (about $300 million in today's dollars) and has
remained close to that level. The FY 2010 Energy and Water
Appropriations bill passed by the Congress allocates $426 million for
fusion energy sciences, which includes $135 million for the U.S.
contribution to ITER. While much useful science and engineering has
been accomplished at these funding levels, it is unlikely that we will
be able to make the final leap to practical fusion power without
sustained support for fusion engineering science and facilities for
answering the questions that lie outside ITER's scope.
Ambassador Kaname Ikeda, ITER Director General, has pointed out
that the current world energy market is about $3 trillion and growing.
The amount invested in energy R&D generally (not just in fusion) is
very modest when compared with the economic value of the market; this
is in sharp contrast to the situation in industries such as information
technology or health sciences, despite the fact that the benefits to
society and the scientific and technical challenges are no less
significant.
Perhaps even more important, most of the world's energy needs are
now being met with nonrenewable fossil fuels that represent the primary
source of the greenhouse gases that are contributing to climate change.
As a safe and essentially inexhaustible source of baseload power that
emits no greenhouse gases, fusion would be a sustainable energy
solution for the long-term.
This is not to say that improvements in energy efficiency,
renewables, and fission, combined with electrification of our
transportation sector, are not key near-term to medium-term challenges
that we must address. But given that there is no single element of
energy R&D that will yield supplies sufficient to meet our overall
objectives of reducing the environmental consequences of CO2
and other emissions and the national security and economic consequences
of a growing reliance on imported petroleum, fusion needs to be an
element of a balanced energy R&D portfolio. Answering the remaining key
science questions about the feasibility of fusion, which is a central
focus of ITER, will enable us to shift our focus to the technological
and engineering challenges of fusion as a power source.
Thank you again for the opportunity to testify. I welcome your
questions on this important topic.
Biography for Thomas E. Mason
Thomas Mason is a native of Dartmouth, Nova Scotia, in Canada. He
graduated from Dalhousie University in Halifax, Nova Scotia, with a
Bachelor of Science degree in physics and completed his postgraduate
study at McMaster University in Hamilton, Ontario, Canada, receiving a
Doctor of Philosophy degree in experimental condensed matter physics.
After completing his Ph.D., he held a postdoctoral fellowship at
AT&T Bell Laboratories in Murray Hill, New Jersey, and then became a
Senior Scientist at Riso National Laboratory in Denmark. In 1993 he
joined the faculty of the Department of Physics at the University of
Toronto.
Thom joined Oak Ridge National Laboratory (ORNL) in 1998 as
Scientific Director for the Department of Energy's Spallation Neutron
Source (SNS) project. In April 2001 he was named Associate Laboratory
Director for SNS and Vice President of UT-Battelle, LLC, which manages
ORNL for the Department. In 2006 he became Associate Laboratory
Director for Neutron Sciences, leading a new organization charged with
delivering safe and productive scientific facilities for studying of
structure and dynamics of materials. In May 2007, Thom was named
Director of Oak Ridge National Laboratory.
Thom's research background is in the application of neutron
scattering techniques to novel magnetic materials and superconductors
using a variety of facilities in North America and Europe. He is co-
author of more than 100 refereed publications and an Associate of the
Quantum Materials Program of the Canadian Institute for Advanced
Research. In 1997, he was awarded an Alfred P. Sloan Foundation
Research Fellowship. Thom was named a Fellow of the American
Association for the Advancement of Science in 2001 and a Fellow of the
American Physical Society in 2007. He received the Distinguished Alumni
Award for the Sciences from McMaster University in 2008.
Thom and his wife, Jennifer MacGillivray, also a native of Nova
Scotia, live in Oak Ridge with their two sons, William and Simon.
Chairman Baird. Dr. Betti.
STATEMENT OF DR. RICCARDO BETTI, PROFESSOR, MECHANICAL
ENGINEERING & PHYSICS AND ASTRONOMY; SENIOR SCIENTIST AND
ASSISTANT DIRECTOR FOR ACADEMIC AFFAIRS, LABORATORY FOR LASER
ENERGETICS, UNIVERSITY OF ROCHESTER
Dr. Betti. Mr. Chairman, Ranking Member Inglis and Members
of the Committee, I am Riccardo Betti, Professor at the
University of Rochester. Thank you for inviting me to testify
today about the status of inertial fusion energy research and a
vision for the future.
Inertial fusion uses the same thermonuclear reactions and
the same hydrogen fuel as magnetic fusion. Like gasoline in the
cylinder of a car engine, fusion fuel must be ignited in order
to produce useful energy. An ignited fuel can produce fusion
energy that can greatly exceed the input energy. If the energy
output is greater than the input, then we have an energy gain
and only then fusion becomes an energy source. Thermonuclear
ignition has been a scientific quest since the 1950s. Like no
other time in history, we are now close to demonstrating
ignition and energy gains in the laboratory.
The path towards economically viable inertial fusion energy
involves three crucial elements: first, the demonstration of
ignition; second, the demonstration of high energy gains; and
third, the development of the technology for a power plant. In
the near future, the National Ignition Facility, the NIF, at
Lawrence Livermore National Laboratory, by far the world's
largest laser, is expected to achieve the first demonstration
of thermonuclear ignition in the laboratory by compressing a
tiny pellet of solid cryogenic hydrogen fuel using lasers.
The current status of inertial fusion energy research in
the United States is dominated by the National Ignition
Campaign with a goal of achieving ignition on the NIF. The
National Ignition Campaign is funded for reasons of national
security by the Stockpile Stewardship Program under the
National Nuclear Security Administration, the NNSA. In parallel
to its national security mission, the National Ignition
Campaign will be able to address many aspects of the physics
principles of inertial fusion energy including ignition and
energy gain. The National Ignition Campaign involves many
institutions and major NNSA facilities. It is crucial to
provide adequate funding to the National Ignition Campaign
because achieving thermonuclear ignition in the laboratory is a
milestone in the development of science and energy security.
This goal should not be undermined by lack of funding. Not now,
since we are so close to achieving ignition.
The next step after ignition is the demonstration of high
energy gain. For a viable power plant, the fusion energy output
must greatly exceed the input energy to the fuel by more than
100 times. It is unlikely that the NIF will achieve the high
gains required for inertial fusion energy. The current
configuration of the NIF will test one approach to inertial
fusion, the indirect drive approach. Other inertial fusion
concepts like direct drive, fast ignition and others funded
through the Office of Fusion Energy Sciences, the OFES, and
NNSA have the potential to generate the gains needed for
inertial fusion energy. Some of these concepts can be tested on
existing NNSA facilities.
But unfortunately, the very limited access to these
facilities constitutes a serious impediment to progress in this
important area and to achieve the wide energy gains for
inertial fusion energy. OFES and NNSA have already formed a
joint program to support high-energy-density physics research.
This partnership should be strengthened to increase access to
NNSA facilities to study high-gain inertial fusion energy
concepts.
Achieving ignition and high gain does not imply that
economically attractive fusion energy is just around the
corner. Major technological and engineering challenges will
still remain even after ignition. Before starting a major
energy development program, it is prudent to undertake an
assessment of the different options. This can begin immediately
with a small exploratory technology program. A power plant
requires a driver to compress the pellet, a target chamber and
many other systems. The driver is the most complex and
expensive component to the power plant. Several drivers have
been proposed. Lasers are the most developed drivers. Other
drivers would likely require longer development paths. An
exploratory technology program should be started with the goal
of assessing and selecting the most attractive driver in order
to move quickly towards an expanded energy development program
once the National Ignition Facility has demonstrated ignition
and energy gain.
Thank you, Mr. Chairman, for allowing me to testify on the
next generation of fusion energy research.
[The prepared statement of Dr. Betti follows:]
Prepared Statement of Riccardo Betti
EXECUTIVE SUMMARY
Nuclear fusion powers the sun and other stars. Harnessing fusion
energy has been a scientific quest since the 1950s. Inertial and
magnetic confinement fusion are the main approaches to fusion energy
pursued in the U.S. Both approaches use a 50-50 mixture of hydrogen
isotopes (deuterium and tritium) as fuel. Like all advanced energy
sources, inertial fusion requires a scientific demonstration of
validity of the concept and a technology program to develop a viable
power plant. The path to inertial fusion energy (IFE) involves three
elements:
The demonstration of the physics principles of
controlled inertial fusion: thermonuclear ignition and burn of
deuterium-tritium (DT) fuel
The demonstration of high energy gain from DT fuel
The development of the technology for an IFE power
plant.
Demonstration of Ignition and Burn: In the near future, the National
Ignition Facility (NIF) at Lawrence Livermore National Laboratory
(LLNL) is expected to achieve the first demonstration of thermonuclear
ignition and moderate energy gain in the laboratory using lasers. In
the indirect-drive approach to inertial fusion, the laser is used to
heat a small metallic enclosure (a ``hohlraum'') to high temperatures.
The heated metal of the hohlraum wall emits x rays that irradiate a
tiny pellet of cryogenic solid DT fuel. The pellet implodes, achieving
extreme pressures and temperatures that turn the solid DT into hot
dense plasma producing copious amounts of nuclear fusion reactions
(what is called ``a burning plasma''). Thermonuclear ignition is a
thermal instability that causes the plasma to self-heat through a
runaway process where fusion reactions increase the plasma temperature
that in turn induces more fusion reactions. An ignited plasma can
produce fusion energy that can greatly exceed the input energy required
to produce the plasma. The process of laser irradiation, pellet
implosion, thermonuclear ignition and energy gain is usually referred
to as ``target physics.'' Demonstrating thermonuclear ignition and
energy gain in the laboratory has been a goal of fusion energy research
for the past five decades, and is widely considered a milestone in the
development of fusion energy, as well as a major scientific
achievement.
The current status of IFE research in the U.S. is dominated by the
National Ignition Campaign (NIC). The NIC is funded for reasons of
national security by the Stockpile Stewardship Program under the
National Nuclear Security Administration (NNSA). In parallel to its
national security mission, the NIC will be able to address many aspects
of burning-plasma physics relevant to inertial fusion energy and will
demonstrate the physics principles of IFE. The NIC involves many
institutions (LLNL, LLE, LANL, General Atomics and SNL) and major NNSA
facilities (NIF, OMEGA and Z). Many diagnostics and experimental setups
are validated on smaller facilities (mostly on OMEGA at the Laboratory
for Laser Energetics) before installation on the NIF.
Recommendation: It is crucial to provide adequate funding to
the National Ignition Campaign. Achieving thermonuclear
ignition in the laboratory is a milestone in the development of
science and energy security. This goal should not be undermined
by lack of adequate funding.
Demonstration of High Energy Gain: The next step in target physics
after ignition is the demonstration of high energy gain. For a viable
IFE power plant, the fusion energy output must greatly exceed the input
energy to the plasma. Energy gain is the ratio between energy output
and input. It is unlikely that the NIF will achieve high gains (> 100)
in the laser indirect-drive configuration.
The 2009 FESAC report\1\ states that ``Alternative IFE concepts
[laser direct-drive, fast ignition, heavy ion fusion and others] funded
through OFES and NNSA have the potential to generate the gains needed
for IFE.'' Present research in alternative IFE concepts is funded by
DOE's Office of Fusion Energy Sciences (OFES) and NNSA, with NNSA
providing limited access to their facilities. Limited access to the
NNSA facilities constitutes a serious impediment to progress in this
important area and to the achievement of high energy gains for inertial
fusion energy. While the NIF is currently configured to fully validate
the scientific principles of the laser indirect-drive approach, it can
also test the laser direct-drive approach with very modest changes to
the existing laser system. The direct-drive approach is simpler since
the laser directly irradiates the solid pellet. It is also more
efficient since it eliminates the need for the intermediate process of
conversion of laser light into x rays.
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\1\ Fusion Energy Science Advisory Committee (FESAC), Advancing the
Science of High Energy Density Laboratory Plasmas, U.S. Department of
Energy, Office of Science, January 2009.
Recommendation: OFES and NNSA have already formed a joint
program to support high energy-density physics research. This
partnership should be strengthened to increase access to NNSA
facilities for research in the area of high-gain inertial-
fusion-energy concepts. Experiments on the NIF should be
carried out to demonstrate ignition and energy gain with the
---------------------------------------------------------------------------
laser direct-drive approach.
Development of the Technology: Achieving ignition and high gain does
not imply that economically attractive fusion energy is just around the
corner. Major technological and engineering challenges will still
remain even after the demonstration of ignition. The development of a
viable fusion power plant requires large scientific and financial
investments. Before launching a major energy development program, it is
prudent to undertake an assessment of the different driver options.
This can begin immediately with a small exploratory IFE technology
program (``small'' here is used for comparison with the ``large''
science program of the National Ignition Campaign that received $458M
in the FY10 Appropriations bill).
Several drivers have been proposed: solid-state and Krypton-
Fluoride (KrF) lasers, Z pinches and heavy ion beams. The driver
compresses the pellet and is the most complex and expensive component
of an IFE power plant. Drivers are part of an integrated system
including a target chamber, injection systems and other components.
Drivers must operate with relatively high repetition rates to produce
enough average power output. Lasers are the most developed drivers.
Small-scale high-repetition-rate KrF and solid-state lasers have been
built and operated. Research in target physics for laser drivers is
also the most advanced. The current experimental campaign will explore
ignition with lasers implying that the target physics issues will only
be resolved for laser drivers. Other drivers will likely require longer
development paths for both the technological development and target
physics. An exploratory IFE program should be started with the goal of
assessing and selecting the most attractive driver option in order to
move quickly towards an expanded energy development program once the
NIF has completed the ignition campaign and reliably demonstrated
fusion-energy gains. Such a program should also assess the viability of
fusion-fission hybrid systems where a blanket of fissionable material
surrounding the fusion reactor is used to amplify the fusion-energy
output. Funding for research in IFE technology has been eliminated in
2009 and no plans are in place to support it in the near future.
Recommendation: It would be beneficial to immediately initiate
an exploratory fusion technology program in parallel to the
ignition campaign to assess the viability of the different
driver options. If successful, such a program will select the
most attractive driver by the completion of the ignition
campaign on the NIF.
Status of Inertial Fusion Energy Research and Vision for the Future
Nuclear fusion powers the sun and other stars. Fusion involves the
merging (e.g., fusing) of light elements. Harnessing fusion energy has
been a scientific quest since the 1960s. Inertial and magnetic
confinement are the main approaches to fusion energy pursued in the
U.S. Both approaches use a 50-50 mixture of hydrogen isotopes
(deuterium and tritium). Deuterium is abundant and can be extracted
easily from sea water. Tritium must be obtained by breeding with
lithium, and lithium is a readily available light metal.
Like all advanced energy sources, inertial fusion requires a
scientific demonstration of viability of the concept and a technology
program to develop a viable power plant. The path to inertial fusion
energy (IFE) involves three elements:
(1) The demonstration of the physics principles of controlled
inertial fusion: thermonuclear ignition and burn of deuterium-
tritium (DT) fuel
(2) The demonstration of high energy gain from DT fuel
(3) The development of the technology for an IFE power plant.
1. Demonstrating Controlled Thermonuclear Ignition and Burn
The demonstration of ignition and burn is the goal of the National
Ignition Campaign (NIC). The NIC is funded for national security
reasons by the Stockpile Stewardship Program under the National Nuclear
Security Administration. The NIC involves many institutions (LLNL, LLE,
LANL, General Atomics and SNL) and major NNSA facilities (NIF, OMEGA
and Z). Many diagnostics and experimental setups are validated on
smaller facilities (mostly on OMEGA at the Laboratory for Laser
Energetics) before installation on the NIF.
Finding: The National Ignition Campaign aims at demonstrating
ignition and moderate fusion-energy gains in the next few years
on the National Ignition Facility (NIF). Preparatory work is
under way and the first attempts to ignition are set to begin
at the end of FY10 on the NIF.
Two recent highlights of the National Ignition Campaign are worth
mentioning.
(1) Early experiments on the National Ignition Facility have
shown good performance of the NIF laser and good coupling of
the laser energy to the target. The NIF has already delivered
energies exceeding one megajoule (one megajoule = one million
joules) and is on track to proceed with the first attempts to
ignition using the indirect drive approach.
(2) Using the laser direct-drive approach, recent experiments
on OMEGA have achieved world record performance in terms of DT
plasma compression and attained the required densities for
fusion. It is likely that, within the next few years, OMEGA
will also demonstrate the temperatures that will scale to those
required for ignition. If successful, OMEGA will validate many
of the physics principles of the direct-drive approach (with
the exception of ignition and burn).
The direct-drive approach is a straightforward alternative to
indirect drive. First, it is simpler since the laser directly
irradiates the solid pellet and the targets do not require metallic
enclosures (hohlraums). Second, it is more efficient since it
eliminates the need for conversion of laser light into x-rays. For
these reasons, the direct-drive approach offers better prospects for
energy applications. While the NIF is currently configured to fully
validate the scientific principles of the laser indirect-drive
approach, it can also test the laser direct-drive approach with very
modest upgrades to the laser system.
Recommendation: The results from OMEGA can and should be used
to field experiments on the National Ignition Facility to
demonstrate ignition and energy gain with the laser direct-
drive approach. This is a necessary step that will resolve most
of the target physics issues for the direct-drive scheme and
will determine if laser direct-drive is a viable option for
fusion energy.
The NIC is currently funded at the level of $458M for FY10. To the
best of my knowledge, some of the key institutions involved in the NIC
are operating under very tight budgets. With the first demonstration of
ignition expected within the next few years, this is not the time to
underfund the ignition campaign. Even small budget increases could
significantly improve the prospects for success.
Recommendation: It is crucial to provide adequate funding to
the National Ignition Campaign. Achieving thermonuclear
ignition in the laboratory is a milestone in the development of
science and energy security. This goal should not be undermined
by lack of adequate funding.
2. Demonstrating High Energy Gain
The next step in target physics after ignition is the demonstration
of high energy gain. For a viable IFE power plant, the product of the
efficiency of the driver (the ratio of the ``wall plug'' energy to
driver energy produced) and the target gain should exceed 10, e.g., a
10 percent efficient driver requires a gain of 100. The target gain is
the ratio between the energy output and the energy input on target. It
is unlikely that the NIF will achieve high gains (> 100) in the laser
indirect-drive configuration--and so an alternative approach may be
required. The 2009 FESAC report\2\ states that ``Alternative IFE
concepts funded through OFES and NNSA have the potential to generate
the gains needed for IFE . . .. [The] alternative concepts in IFE will
play a crucial role in the development of inertial fusion energy, since
high gains and high driver efficiencies are required features of an
economically viable IFE power plant.'' Present research in alternative
IFE concepts is mostly funded by DOE's Office of Fusion Energy Sciences
(OFES) and NNSA, with NNSA providing limited access to their
facilities. Limited access to the NNSA facilities constitutes a serious
impediment to progress in this important area and to the achievement of
high energy gains for inertial fusion energy.
---------------------------------------------------------------------------
\2\ Fusion Energy Science Advisory Committee (FESAC), Advancing the
Science of High Energy Density Laboratory Plasmas, US Department of
Energy, Office of Science, January 2009
---------------------------------------------------------------------------
There are several options for achieving the gains required for IFE
using lasers: direct-drive, fast ignition and shock ignition. Heavy ion
fusion requires a heavy ion accelerator, and Z-pinch fusion requires a
pulsed-power device.
Heavy ion accelerators are attractive drivers from the standpoint of
wall-plug efficiency. Recent theoretical work has indicated that heavy-
ion fusion (HIF) could achieve high gains through direct irradiation of
the target. However, there is little or no experimental work on
implosion physics with heavy-ion drivers. Since there are not existing
HIF implosion facilities, it is not possible to easily acquire critical
experimental data to make a valid assessment of the target physics
requirements for HIF. An IFE development path for heavy-ion fusion will
inevitably require both a target physics and a technology development
program. With little available experimental data on heavy-ion fusion
implosions and the lack of HIF implosion facilities, it is likely that
an IFE development path based on heavy ion fusion will be lengthy and
uncertain.
Z-pinch fusion uses the indirect drive approach and requires high-gain
targets (gains of 100 or more). Current Z pinches such as the Z-machine
at Sandia National Laboratory have demonstrated reasonable single-shot
performance and high x-ray yields. The rate of progress in target
physics is mostly limited by the low shot rates of large Z pinches.
Theoretical work indicates that it may be possible to design high yield
targets that can satisfy the requirements for inertial fusion energy.
Z-pinch fusion requires driving large currents through massive
transmission metal lines that are partially destroyed at every shot.
Since the cost of replacing the transmission lines would exceed the
value of the fusion-energy output, a Z-pinch based IFE power plant will
require recycling the large amounts of metal of the transmission lines.
While some interesting ideas have been put forward to address this
issue, a technology development path for Z-pinch fusion is highly
uncertain.
Lasers are the most developed drivers and the target physics for laser
fusion is the most advanced. Laser drivers are used for direct drive,
fast ignition and shock ignition. Laser direct drive has been pursued
in the U.S., Europe and Japan for over 30 years. According to
theoretical analyses, laser direct drive offers the possibility of
achieving high energy gains. Since existing laser drivers have poor
efficiencies, gains in excess of 100 are required for fusion energy.
The conventional approach to laser direct drive uses a single step with
a single laser pulse driving the compression and the heating of the
thermonuclear fuel. This approach is currently under investigation at
two implosion facilities: the OMEGA laser at the Laboratory for Laser
Energetics of the University of Rochester, and the GEKKO laser at the
Institute for Laser Engineering of Osaka University in Japan. Both
OMEGA and GEKKO use glass laser technology. Until recently, target-
physics studies on laser direct drive were also pursued at the NIKE
laser facility of the Naval Research Laboratory (NRL). NIKE is a
Krypton-Fluoride (KrF) gas laser producing laser light with a
wavelength shorter than the other large glass lasers. KrF lasers are
more efficient than glass lasers. Their short wavelength light
efficiently couples the laser energy to the target and allows operation
at relatively high laser intensities. While short wavelength light
improves several aspects of the target physics, it poses more severe
technological constraints on the optical components of the laser
system. The NRL IFE program did not receive funding in the FY09 Omnibus
Appropriations bill and its future is uncertain.
A wealth of experimental data is available on direct drive
implosions. The data includes surrogate targets (mostly made of plastic
shells) and cryogenic solid deuterium (D2) and deuterium-
tritium (DT) targets. The latter are the targets of most interest to
inertial fusion energy. To date, cryogenic DT targets have only been
used for implosion experiments on the OMEGA facility. Recent cryogenic
implosion experiments on OMEGA have achieved high compression of
thermonuclear fuel. While the required densities have been achieved,
further progress needs to be made to raise the temperature (by about 50
percent-70 percent) and the fusion yield (by about two to four times)
from the compressed DT fuel. Only when all these requirements (density,
temperature and fusion yield) are simultaneously met in cryogenic
implosions on OMEGA, can one achieve a full understanding of the target
physics and full validation of the predictive capability. Achieving an
experimental validation of the predictive capability is an important
requirement for the design of robust high-gain targets. OMEGA is close
to achieving such an experimental validation (with the exception of the
validation of ignition and burn physics that requires experiments on
the NIF).
Achieving gains in excess of 100 with the conventional approach to
direct drive requires very large lasers. An IFE laser driver should
deliver a few megajoules of ultraviolet light to the target at a rate
of about 10 shots per second. Krypton-Fluoride and advanced solid state
lasers offer the promise of high efficiency and high repetition rates,
but even in the most optimistic scenario, a power plant based on the
conventional direct-drive approach will require large megajoule-class
lasers and targets with gains above 100. The need for large high-
repetition-rate laser systems is the main difficulty in the development
of the conventional laser direct-drive approach to inertial fusion
energy.
Fast ignition is a relatively new concept that separates the
compression and the heating of the thermonuclear fuel. The compression
is driven by a conventional system (laser or other driver), and the
heating is induced by a beam of energetic electrons produced by the
interaction of a short-pulse ultra-high-intensity laser beam with the
target. Fast ignition research is actively pursued in the U.S., Europe
and Japan. Theoretical analyses indicate that fast ignition may lead to
energy gains well above the gains of conventional direct drive.
However, such theoretical calculations are incomplete and the physics
principle concerning the interaction of intense light with matter and
the transport of energetic electrons in plasmas are poorly understood.
While fast ignition may require a relatively small compression laser (a
sub-megajoule laser), it is likely that providing the necessary
external heating power will involve a large high-power laser ( 100
kilojoule petawatt-class laser--one petawatt = 1000 trillion watts).
Presently, the largest petawatt lasers are the OMEGA EP laser (2.5
kilojoules) at the Laboratory for Laser Energetics and the FIREX laser
(10 kilojoules) at Osaka University.
Since little experimental data on the target physics for fast
ignition is available, it is difficult to make an assessment on its
viability as an option for fusion energy. In the past, the lack of
experimental facilities with a dual integrated laser system (the
compression and heating lasers working together) has prevented the
acquisition of the necessary data. However, the U.S. and Japan have
recently completed the construction of two integrated facilities that
can explore the fast ignition concept. Such integrated laser systems
are OMEGA at the Laboratory for Laser Energetics, and FIREX-I at Osaka
University. A third integrated facility will soon be available at
Lawrence Livermore National Laboratory. The OMEGA facility includes the
OMEGA compression laser and the OMEGA-EP high-power laser, the FIREX-I
facility includes the GEKKO compression laser and the FIREX high-power
laser, and the NIF will soon include the ARC high-power laser. These
three facilities have the potential to rapidly advance the target
physics for fast ignition. The main obstacle to such advances is the
very limited access granted to fast ignition studies on the U.S.
integrated facilities OMEGA and NIF. For example, only five days of the
OMEGA facility were devoted to integrated fast ignition experiments in
FY09. With such a limited time allocation, it is difficult to make
meaningful progress in fast ignition. The reason for this limitation is
that such facilities are funded by NNSA, whose primary mission does not
include fusion energy development. Inadequate access to the integrated
NNSA laser facilities is currently the main obstacle to acquiring the
necessary experimental data required to validate the fast ignition
scheme. The lack of experimental data on the target physics as well as
the complexity of the scheme and targets renders highly uncertain the
development path of fusion energy based on the fast ignition concept.
Shock ignition is a very new concept introduced in 2007. Similarly to
fast ignition, shock ignition is also a two-step process where a strong
shock wave is used to heat the thermonuclear fuel previously assembled
by a compression laser. An advantage of shock ignition is that the
shock can be launched by the same laser used for the compression, and
therefore it requires a single laser. Much of the target physics for
shock ignition is a straightforward extension from laser direct drive.
However, launching strong shock waves requires relatively high laser
intensities and there are concerns about the coupling of the laser
light to the target and other negative effects that occur at high
intensities. Most of the theoretical work on shock ignition to date
comes from computer simulations carried out at the Laboratory for Laser
Energetics, the Naval Research Laboratory, Lawrence Livermore National
Laboratory and the Centre Lasers Intenses et Applications in Bordeaux
(France). This work shows that high energy gains may be possible with
shock ignition using a sub-megajoule driver. Recent experiments on the
NIKE laser, target design work and computer simulations from NRL have
indicated that Krypton-Fluoride lasers are particularly suitable for
shock ignition because they provide a more effective drive for the
shock and reduce the risks (to the target) of operating at high
intensities. This interesting research stopped in 2009 when the NRL
program did not received funding in the FY09 Omnibus Appropriations
bill. While the simulation results are promising, there is not
sufficient available experimental data on the target physics to make an
assessment of shock ignition as a viable scheme for fusion energy. The
only available implosion data on shock ignition comes from a few
experiments on the OMEGA laser. Acquiring meaningful experimental data
requires access to the NNSA laser implosion facilities OMEGA and NIF.
Like fast ignition, access to these facilities for shock-ignition
research is very limited. For example, only one day of operation of the
OMEGA facility was devoted to shock ignition in FY09. Inadequate access
to the NNSA laser facilities is currently the main obstacle to
acquiring the necessary experimental data required to validate the
shock-ignition scheme. Due to the lack of experimental data on the
target physics, the development path for shock ignition is uncertain.
Finding: Laser drivers are the most developed drivers for
inertial fusion. The target physics for laser direct drive is
also the most advanced. Because of the relatively low driver
efficiency, laser-based inertial fusion energy requires high
gain targets (with gains above 100). Laser direct drive, fast
ignition or shock ignition may provide such high gains. A power
plant based on conventional direct drive will likely require
large and expensive megajoule-class lasers. Fast and shock
ignition may require a significantly smaller driver than
conventional direct drive. However, little experimental data is
available for fast and shock ignition to make a valid
assessment of their viability for fusion energy. Heavy-ion
drivers are more efficient than lasers but little or no
experimental data is available on implosion physics for heavy
ion fusion and there are no plans to acquire such data in the
near future. Z-pinch fusion uses the indirect-drive approach
and requires high gains (about 100 or more). Z-pinch research
has made progress in target physics but serious questions
remain on the viability of Z pinches as fusion-energy drivers.
Existing NNSA facilities have the capability of exploring the
physics principles of direct- and indirect-drive laser fusion, as well
as fast and shock ignition. Fast and shock ignition research is
currently funded by the OFES. Access to the NNSA facilities for fast
and shock-ignition experiments is currently very limited since NNSA's
mission does not include fusion-energy development. This limited access
is currently the main obstacle to acquiring the necessary experimental
data required to validate high-gain IFE concepts.
Recommendation: OFES and NNSA have already formed a joint
program to fund high-energy-density physics research. This
partnership should be strengthened to increase access to NNSA
facilities for research in the area of high-gain inertial
fusion energy concepts.
3. Developing the Technology for Inertial Fusion Energy
Achieving ignition and high gain does not imply that economically
attractive fusion energy is just around the corner. Major technological
and engineering challenges will still remain even after the
demonstration of ignition. The development of a viable fusion power
plant requires large scientific and financial investments. Drivers
compress the pellet and are the most complex and expensive component of
an IFE power plant. The driver is part of an integrated system
including a target chamber, injection systems and other components.
Drivers must operate with relatively high repetition rates to produce
enough average power output.
Finding: Several IFE drivers have been proposed: solid state
lasers, Krypton-Fluoride lasers, Z pinches and heavy-ion beams.
Drivers are part of an integrated system including a target
chamber, injection systems and other components. While the
technology of some drivers is more advanced than others, none
of them offers a development path free of major engineering and
technological challenges.
Therefore, before launching a major energy development program, it
is prudent to make an assessment of the different driver options. This
can begin immediately with a small exploratory IFE technology program
(``small'' here is used for comparison with the ``large'' science
program of the National Ignition Campaign).
In the past ten years, the High Average Power Laser Program, funded
by NNSA under congressional mandate, was engaged in IFE technology
development for KrF and solid state lasers. This program was not funded
in the FY09 Omnibus Appropriations bill and no funding is currently
provided for IFE technology.
Lasers are the most technically advanced drivers. Small-scale high-
repetition-rate KrF and solid-state lasers have been built and tested.
Research in target physics for laser drivers is also the most advanced.
Furthermore, the current experimental campaign will explore ignition
with lasers implying that all the target physics issues will only be
resolved for laser drivers. Other drivers will likely require longer
development paths for both the technological development and the target
physics. An exploratory IFE program should be started with the goal of
selecting the most attractive driver option in order to move quickly
toward an expanded energy development program once the NIF has
demonstrated ignition and energy gains.
Because of the engineering and technological difficulties involved
with fusion energy, it is important to assess/explore all possible
schemes including fusion-fission hybrids. A fusion-fission hybrid power
plant consists of a fusion reactor (the ``engine'') surrounded by a
blanket of fissionable material. This concept has been recently
promoted by the Lawrence Livermore National Laboratory (LLNL). The
fissionable material is depleted uranium or spent nuclear fuel, while
the fusion engine is based on the laser indirect-drive approach. Since
the fission blanket amplifies the energy output from the fusion engine,
a relatively low-gain laser indirect-drive (or direct-drive) scheme may
suffice in its role as neutron source. Advocates argue that the LLNL
approach to fusion-fission hybrids offers the shortest development path
for inertial fusion energy since the target physics and the required
target gains are essentially the same as the ones explored by the NIF
within the next few years.
In light of these possible advantages, an exploratory IFE
technology program should also assess the viability of fusion-fission
hybrid systems and make a determination on the benefits of such systems
and the possibility of a shorter development path.
Recommendation: It would be beneficial to immediately develop
an exploratory fusion technology program in parallel to the
ignition campaign to assess the viability of the different
driver options. If successful, such a program will select the
most attractive driver by the completion of the ignition
campaign on the NIF.
Additional technical information, findings and recommendations can be
found in:
Fusion Energy Science Advisory Committee, Advancing
the Science of High Energy Density Laboratory Plasmas,
(Chapters 7, 9, 11), U.S. Department of Energy, Office of
Science, January 2009.
Fusion Energy Science Advisory Committee, Review of
the Inertial Fusion Energy Program, U.S. Department of Energy,
Office of Science, March 2004.
Biography for Riccardo Betti
Dr. Riccardo Betti is currently Professor of Mechanical Engineering
& Physics and Astronomy at the University of Rochester. He is also
Director of the Fusion Science Center for Extreme States of Matter,
Senior Scientist and Assistant Director for Academic Affairs at the
University of Rochester's Laboratory for Laser Energetics.
Dr. Betti has conducted research in plasma physics, inertial and
magnetic confinement fusion for over 20 years. He is Vice-Chairman of
the Department of Energy Fusion-Energy-Science Advisory Committee
(FESAC), and Steering Committee Member of the High-Energy-Density
Science Association. He was Chairman of the Plasma Science Committee of
the National Academies in 2006-09, and Chairman of the FESAC sub-panel
on High-Energy-Density Physics in 2008-09. Dr. Betti is a Fellow of the
American Physical Society for his pioneering work on ablative fluid
instabilities in inertial confinement fusion and energetic particle
instabilities in magnetic confinement fusion. He is a recipient of the
Edward Teller Medal for his seminal contribution to the theory of
thermonuclear ignition and implosion physics for inertial confinement
fusion. Dr. Betti received a ``laurea cum laude'' degree in Nuclear
Engineering from the University of Rome, and a Ph.D. in Nuclear
Engineering from the Massachusetts Institute of Technology. He has co-
authored over 100 refereed articles in plasma physics, magnetic and
inertial confinement fusion.
Chairman Baird. Thank you, Dr. Betti.
Dr. Fonck.
STATEMENT OF DR. RAYMOND J. FONCK, PROFESSOR OF ENGINEERING
PHYSICS, UNIVERSITY OF WISCONSIN-MADISON
Dr. Fonck. Mr. Chairman, Ranking Member Inglis and Members
of the Committee, thank you for the opportunity to testify
today. I got the instruction from your letter to say what our
vision for the next 10 to 20 years is, and I thought about it
and said the biggest vision is: we should not have this hearing
again in 20 years. We should not be talking about fusion energy
science; we should be talking at that point about fusion energy
development, and there is a crucial difference. So to answer
your question, I will give you an example of a path we could
take to pursue in the next 10 to 20 years to get in that
direction.
In spite of the scientific progress we have made, it is no
secret there is skepticism on the credibility or timeline of
fusion energy but much of that can be traced to the fact that
the full range of technical challenges is not being addressed.
These challenges are--some of them have been mentioned--
demonstrating and exploring the burning plasma state, creating
predictable, high-performance continuous plasma, taming the
plasma material interface and harnessing fusion power from the
very energetic neutrons released in fusion. Addressing these
four challenges would provide the knowledge base to establish
the credibility of fusion as an energy source and motivate a
decision to establish a fusion energy development program.
There has been outstanding progress in fusion energy
science, as has been mentioned here already, under the auspices
of the Department of Energy. Most of this is focused on the
properties of the extremely hot fuel or plasma required for
fusion energy and reactions to occur. But it is very important,
and it must be emphasized, that fusion science is not just
plasma physics. The frontiers of fusion science research are
moving to the critical issues of the last two fusion
challenges: the plasma-wall interactions and harnessing fusion
energy. At the same time as these frontiers are moving, our
experimental facilities are aging. Our leading experiment is
over 20 years old. The next-generation state-of-the-art
facilities and capabilities are being developed outside the
United States. The fact that we have not positioned ourselves
to lead in addressing the first two challenges because of these
aging facilities, and that we haven't built anything in 20
years, puts us in a unique position, however, of being able to
address more aggressively the last two elements of the fusion
challenge. An emphasis on the complex processes occurring in
the plasma material interfaces, their integration with the
systems with that extract energy from the fusion system and the
effects of the fast neutrons on those processes, should be the
focus of the domestic U.S. program in the ITER era. This
program and ITER together will address most of the critical
issues underlying the credibility of fusion energy. Just as
importantly, it starts the United States on the path to benefit
economically from its long-term investments in fusion science
research. Indeed, the intellectual property rights that accrue
from the development of fusion will concentrate in these areas,
not in the plasma sciences directly.
So it is time to create a plan to put the U.S. fusion
program on a trajectory towards leadership in the next
generation of fusion research. To accommodate realistic
budgets, specific programs and facilities in our program will
need to be redirected or completed to free resources for these
new directions. Domestically, the program should move to
address the pending nuclear and energy-related issues that
fusion will present. These scientific challenges will be
addressed first in small-scale studies, material studies,
computational modeling, et cetera. But this effort should
culminate in a national, integrated fusion nuclear science test
facility as the central fusion facility in the United States.
It will provide the needed integrated test of our understanding
of the coupled plasma-wall energy conversion systems. Whatever
form this facility takes, this centerpiece experiment in the
United States should be a deuterium-tritium facility to access
the full range of fusion nuclear issues.
The transition of the domestic program to an increasingly
strong focus on fusion nuclear sciences can be executed over
the next decade or so concurrent with the construction and
initial operation of ITER. As ITER construction winds down, the
roll-off of those funds could be applied to this new national
facility to meet the new challenges. Pursuing this program
would vault the U.S. program into leadership of critical areas
of the overall fusion challenge. In the ITER era, the research
activities on ITER and this U.S. program would arguably define
the centers of gravity of fusion science and engineering
development and will expedite the decision whether to develop a
demonstration fusion reactor either by the U.S. Government or
industry or some combination thereof.
So there is a pressing need for plans, A, to evolve--a
world-leading fusion nuclear science program under realistic
budgets, and B, to develop the technical case for an evolution
of the program into a fusion energy development program as soon
as it can. To support developing those plans, the planning of
scientific missions and conceptual designs of requisite
facilities to match those missions should begin immediately.
Support of H.R. 3177, the Fusion Engineering Science and Fusion
Energy Planning Act of 2009, would provide funding to start
this transformation of the program.
Finally, I just want to comment on inertial fusion, because
I have been concentrating on magnetic. If its the campaign to
demonstrate ignition of fusion plasmas via inertial confinement
in the National Ignition Facility is imminent. The achievement
of ignition in NIF will be exciting and historic. It will
rightly demand a reexamination of our national position on
inertial fusion energy, or IFE. As the ideas and proposals for
moving forward towards an IFE program evolve after results are
obtained from NIF, it would be valuable to have a disinterested
expert panel outside the community evaluate the prospects for
inertial fusion energy to inform and motivate any decision
about moving forward to a new inertial fusion energy science
program.
Again, thank you for the opportunity to address the
Committee.
[The prepared statement of Dr. Fonck follows:]
Prepared Statement of Raymond J. Fonck
Mr. Chairman, Ranking Member Inglis, and Members of the Committee,
thank you for the opportunity to testify today. In my testimony I will
try to describe how the U.S. Fusion Energy Sciences program has been
quite successful, but has been, through historical and artificial
constraints, unable to address key issues that must be resolved before
practical fusion energy can be reached. I will also suggest one
possible path along which these issues can be resolved within a
reasonable budgetary envelope.
Research on the properties of high-temperature plasmas, the fuel
for fusion reactors, has made tremendous strides in the past decades.
In the future, the scientific frontiers of fusion will increasingly
move to the complex interactions among the cooler plasma edge, the
materials of the surrounding chamber, and energy extraction systems,
and the role of neutrons in modifying those interactions. To address
these critical issues and motivate a future fusion energy development
program, it is time to start building a fusion nuclear science program
in the fusion R&D portfolio. It will start with modest activities in
materials and related research, and should have a longer-term goal of
deploying a new national fusion nuclear science research facility as
the centerpiece of the U.S. domestic experimental effort in magnetic
fusion in the ITER era. The transition to these new efforts will be
gradual and must be funded during ITER construction in large part by
completing existing programs. Strategic plans for the evolving program
need to be developed. In addition, the anticipated success of the
ignition campaign on NIF should motivate an examination of proposals
for a new program in inertial fusion energy science and/or engineering.
Support of H.R. 3177, the Fusion Engineering Science and Fusion Energy
Planning Act of 2009, would provide funding to assist the start of
necessary transformations in the program.
Progress in Plasma Sciences Motivates a New Phase of Fusion Research
Fusion is the nuclear process that produces energy in the interior
of the sun and stars. Developing fusion power in the laboratory truly
means capturing the power of the sun here on Earth, and is a grand
challenge of science and technology. The path to producing useful
energy through the fusion process here on Earth is complex, and the
quest is not complete.
With readily available fuel and significant environmental
advantages, fusion energy is a candidate for significant carbon-free,
base-load energy production in the second half of this century.
However, major new energy technologies can require decades to strongly
penetrate the market after introduction. To offer the possibility of
fusion power in a useful timeframe, we need to move as quickly as we
can now to exploit and complement the advances in fusion energy R&D
that are expected in the next decade or more.
Historic achievements have been made and others are eagerly
anticipated in the world of fusion energy sciences research. Past
demonstrations of 10-20 MW of fusion power production in the TFTR (in
the U.S.) and JET (in the E.U.) experiments confirmed the promise of
magnetic confinement of fusion plasmas in the 1990's. The U.S.
subsequently entered the ITER project to allow U.S. scientists to
explore magnetically confined burning plasmas. A burning plasma exists
when the power released by the fusion nuclear reactions is roughly 5-10
times larger than the power injected to sustain the fusion process. All
of those experiments are based on the tokamak concept, which is a type
of donut-shaped magnetic bottle that holds the hot fusion fuel away
from any material walls.
In addition to the magnetic confinement approach with tokamaks, the
demonstration of ignition in inertially driven fusion targets in the
National Ignition Facility is planned for the near future. This relies
on powerful lasers to compress solid fusion fuel pellets to heat them
to fusion temperatures and create a very short, powerful release of
fusion energy.
There has been outstanding progress in fusion energy science
research under the auspices of the Department of Energy Office of
Science programs. Most of this has focused on the properties of the
extremely hot fuel, or plasma, required for fusion reactions to occur.
Our understanding of the extraordinarily complex problem of small-scale
plasma fluctuations that lead to increased heat losses, and hence
inhibit the ability to achieve the fusion state, has evolved to the
point where these fluctuations can often times be suppressed. This
leads to increasing plasma temperatures and fusion power. The
understanding and predictability of fusion-grade plasmas have been
refined to the point that the plasmas can be actively controlled to
avoid damaging large-scale instabilities. Techniques to heat and
manipulate these plasmas to finely tailor the plasma state and thereby
optimize the potential to produce fusion reactions are being
successfully developed. Similar progress has been made in understanding
inertially confined plasmas in defense-related DOE programs. With all
of these accomplishments in plasma sciences and supporting
technologies, we are resolving some of the major plasma physics issues
in the overall challenge of establishing the base for fusion energy.
These developments represent the culmination of decades of research
in high temperature plasma sciences, and motivate us to confront the
additional challenges remaining to making the case for fusion energy.
Hence, it is indeed timely to consider ``The next generation of Fusion
research,'' and it is time to start broadening the scope of the
programs to expedite decisions on a commitment to fusion energy
development.
Broadening the Fusion Research Portfolio to Enable a Future Energy
Development Program
The DOE fusion science programs have, somewhat of necessity and
somewhat due to artificial constraints, concentrated on studying many
of the relevant plasma science questions that arise in moving towards
fusion energy conditions. However, the fusion challenge is much broader
than high temperature plasma science and its attendant enabling
technologies. The development of the knowledge base for fusion energy
requires a variety of topics to be addressed, including basic high
temperature plasma science, measurement sciences, materials, the
effects of nuclear interactions, and the engineering technology
challenges of capturing and converting fusion energy. In fact, the full
range of issues is well known, and only a fraction of them are
addressed in the present program.
The research and development needed to establish the foundation for
fusion energy development were identified in plans for fusion energy
research in the 1970's, acknowledged in repeated reviews and planning
documents since then, and most recently restated by a major Fusion
Energy Sciences Advisory Committee study that was charged to identify
the gaps in our knowledge that remain, assuming successful completion
of the ITER burning plasma program. While the details vary, the general
issues identified through the years have not changed, mainly because
they are driven by the physical challenges of attaining and exploiting
the fusion state.
From the most recent assessment of fusion, the fusion R&D
enterprise must at least address the following four challenges.
FUSION CHALLENGES:
Demonstrating and exploring the burning plasma state
Creating and controlling a fusion plasma that
releases several 100 MW of energy, and understanding
the effects of very energetic fusion-created particles,
is a grand challenge of fusion science research.
Creating predictable, high-performance, steady-state
plasmas
A continuously burning plasma that behaves
predictably and is highly efficient is needed for
economical fusion reactors
Taming the plasma-material interface
Magnetic confinement sharply reduces the contact
between the plasma and the containment vessel walls,
but such contact cannot be entirely eliminated.
Advanced wall materials and magnetic field structures
that can prevent both wall erosion and plasma
contamination are required.
Harnessing Fusion Power
Fusion energy from deuterium-tritium (D-T) reactions
appears in the form of very energetic neutrons. The
understanding of the effects of these neutrons on the
surrounding materials and the fusion plasma, and the
means of capturing this energy, while simultaneously
breeding the tritium atoms needed to maintain the
reaction, must be developed.
The first two challenges are addressed by research focused on
understanding the high-temperature plasma properties in the hot central
core region of these magnetically confined plasmas. This research has
been very successful, and will remain a vibrant field well into the
future.
However, the scientific frontiers of fusion are inexorably moving
to examine the critical issues of the plasma interactions with the
material chamber, and methods of extracting the energy from the fusion
process. These topics are the focus of the last two challenges. For
example, it is now clear that the processes in the edge plasma region,
where the hot plasma interacts with the surrounding material chamber,
profoundly influence the overall behavior of the plasma in the central
hot region. The processes that occur in the plasma-chamber-energy
conversion systems increase in number and complexity in the presence of
a high-energy neutron flux, where the properties of the materials and
their interactions with the plasma edge, can be significantly altered.
This interacting plasma-chamber-energy conversion system will
eventually need to be examined in integrated tests. This will encompass
the entire fusion system, and complement the burning plasma studies to
address all four fusion challenges.
It is no secret that there is skepticism on the credibility or
timeline of fusion as an energy source, and much of it can be traced to
the fact that this full range of challenges is not being addressed.
Nevertheless, in those areas that have been addressed in detail (mainly
concerning 1 and 2 above), the progress has been steady, impressive,
and acknowledged. Outside evaluations of the science developed by the
fusion research program have affirmed the high quality and integrity of
that scientific enterprise. However, few resources have been focused on
addressing the last two fusion challenges listed above, and hence
progress there has been slow, which in turn undermines the argument for
accelerating the development of fusion energy.
With the entry into the era of burning and ignited plasmas, it is
time to broaden the fusion research enterprise to address, at
appropriate levels, the full range of fusion challenges. ITER will
provide us unique tests of the physics of the high-temperature core of
a fusion system and some reactor-relevant technology. An emphasis on
the complex processes occurring in the plasma-material interfaces,
their integration with the systems that extract energy from the fusion
system, and the effects of neutrons on those processes, should be the
focus of the domestic U.S. program in the ITER era. These two efforts
together will address most of the critical issues underlying the
credibility of fusion energy. This will then provide the government and
industry the information needed to decide any future commitment to
fusion energy development as soon as possible.
Most present fusion-energy related research is in the portfolio of
the Office of Fusion Energy Sciences in the Office of Science of DOE,
and is concentrated on the magnetic confinement approach. It is
establishing the scientific basis for fusion energy, but it is natural
to expect that at some time in the future this program will evolve to a
dedicated fusion energy development program, either inside or
presumably outside of the Office of Science. This evolution will occur
as the credibility of fusion energy is established through focused
research activities that address in part all of the fusion challenges
above. Continuing basic science studies to support this focused energy
development program would continue in the Office, similar to other
programs there. Indeed, this is precisely what the National Academics
recent Decadal Study for Plasma Physics suggested will be the natural
evolution of this program.
A major challenge of the present fusion research program is to
establish the credibility of fusion energy to expedite this transition
to an energy development program. To that end, DOE and the research
community soon need to develop a long-range strategy to both justify
and smoothly effect this transition towards an energy development
program, assuming success in the present science program. Moving in
this direction can be done within reasonable funding levels and will
attract a new generation of researchers.
BROADENING THE FUSION PORTFOLIO IN THE NEAR-TERM
While one can anticipate the future fusion energy development
program, the ability to move the present fusion science program forward
within realistic budget constraints is hampered by both externally and
internally imposed constraints.
The program is strongly focused on the underlying plasma science of
the fusion plasma core. It does not address the rich array of
scientific and engineering challenges that arise in the entire fusion
system, and that must be addressed in the quest to demonstrate the
viability of fusion power. Practically, this resulted from an external
constraint on the program that there could be little research into the
engineering sciences, material sciences, and technologies relevant to
fusion energy until the whole range of underlying plasma physics issues
is addressed.
While this constraint may have reflected priority setting in a
resource-limited program and been used as a means of restraining the
appetite for significantly increased budgets without clear priority
setting, it is increasingly anachronistic. Without removing this
constraint, we will miss the opportunity to develop the knowledge and
skills in precisely those areas of the fusion problem that will lead to
economic advantages from our long investments in fusion research. In
considering the next phase of fusion research, I assume that this
constraint is lifted and the Office of Fusion Energy Sciences will be
free to allocate resources across the relevant broad range of issues to
optimize the path to a fusion energy development program within
available resources.
The fusion research community imposes another constraint on itself
by seeing its resources as locked and concluding that there is little
opportunity to move forward to new frontiers, which often means new
facilities to access new physical states. This sense of insurmountable
limits arises from real constraints on the amount of funding available,
but also from an unwillingness to acknowledge clearly focused goals and
make hard priority choices to achieve those goals.
This can be addressed by developing a plan for fusion R&D in the
next decade and beyond that makes the hard choices needed to regain
U.S. leadership in selected areas that focus on the credibility and
eventual economic exploitation of fusion as an energy source. In
particular, an eight- to ten-year plan that includes a growing activity
in the critical fusion nuclear science and engineering issues that are
relevant to exploitation of the energy-producing plasma should be
developed and pursued. The goal of this plan would be to move smoothly
over the next decade during ITER construction to include in the U.S.
fusion program a world-leading fusion nuclear science program, with
access to the requisite tools and resources to address the critical
issues during the ITER era.
As mentioned above, the U.S. fusion science research program is
addressing mainly the first two of the four main fusion challenges.
However, the next-generation, state-of-the-art facilities and
capabilities to address both of these challenges are being developed
and located outside the U.S. The burning plasma program is now centered
on ITER in France, and the large major tokamaks that are cited as
necessary for ITER preparation and operation are located in the EU and
Japan. Likewise, tokamaks with superconducting coils and world-class
stellarator experiments will lead the research to resolve the issues
inherent in steady-state plasma operations. The new superconducting
tokamaks are located in China, South Korea, and Japan, while the large
stellarator experiments reside in Germany and Japan. U.S. scientists,
using older facilities, have certainly made seminal contributions to
these various concepts--indeed, some of these facilities have benefited
directly from U.S. developments. However, it is inevitable that
research on these new facilities will guide fusion energy science
developments in these areas in the future. Hopefully, our scientists
will collaborate on these international facilities, but the net
consequence is that the U.S. is off-shoring its ability to lead in the
first two of the four challenges of fusion energy development.
This, however, puts the U.S. community in the position of being
able to address more aggressively the last two elements of the fusion
challenge. In particular, we have a unique opportunity to pursue world
leadership in the new frontiers of fusion: plasma-wall interactions,
materials, and harnessing fusion energy. These areas cover the problems
inherent in handling, capturing, and converting fusion neutrons and
heat created by the fusing plasma to useful power. The problems
include: plasma, atomic, molecular, and nuclear physics; material
sciences; neutron sciences; and associated engineering challenges.
Starting to move the U.S. program in the direction of addressing these
integrated problems complements the planned research on ITER and
directly confronts major points of criticism of fusion power. Most
importantly, it starts to position the U.S. to benefit economically
from its long-term investments in fusion science research. Indeed, the
intellectual property rights that accrue from fusion development will
concentrate in these areas, since the plasma science knowledge to
address the first two elements is openly developed and available.
A CONSTRAINED, AGGRESSIVE FUSION ENERGY RESEARCH PLAN
A fusion program with a properly expanded scope to include a
growing focus on the underlying nuclear and energy science issues can
be readily envisioned. One such scenario is outlined here, but it is
only conceptual. Wide variations of this approach could emerge as
planning goes forward. In any case, it must be constrained to realistic
budgets, include milestone commitments, and contain sometimes-painful
priority decisions.
I assume that the ITER construction will be supported, and U.S.
domestic research funds will include the present level, with inflation
escalation, and any increases that the program can successfully compete
for as the Office of Science budget increases though pursuit of the
goals of the America COMPETES Act. This funding profile will require
that specific programs and facilities in the U.S. program be completed
to provide resources for new directions of research.
The central activities addressing the first two elements of the
fusion challenge will migrate to collaborative research on
international facilities. That is, the research addressing the burning
plasma and steady-state issues for fusion plasmas will be pursued
overseas, and major U.S. facilities will be transitioned out as their
programs are completed. As the new superconducting and steady-state
plasma facilities come into full operation overseas, collaborative
agreements will need to be developed or expanded to provide our
scientists access to those capabilities that are not available in the
U.S. Participation in ITER burning plasma studies will eventually
require the development of a U.S. ITER science team. This team could
also execute that collaborative research on other state-of-the-art
tokamaks in anticipation of the ITER collaborations.
The stellarator (mentioned earlier) is a magnetic confinement
concept that is similar to the tokamak but in a sense offers simpler
plasma properties at the expense of more complex mechanical systems. It
may provide a potential breakout concept for a fusion reactor concept,
and international collaboration is also critical here. However, there
may be a world-leading role for the US to pursue modest facilities to
resolve critical issues. The domestic program in the U.S. should retain
a viable research activity in this area to support informed decisions
on future reactor concepts.
Domestically, the U.S. fusion science program should now begin to
address the pending nuclear and energy-related issues that fusion will
present. The scientific challenges of plasma-wall interactions can be
addressed initially in present tokamaks, move to dedicated test stands
to understand underlying physics, and eventually be a focus in the
first phases of a central U.S. facility dedicated to fusion nuclear
science issues. The fusion nuclear science program should ramp up over
time to at least include: elemental material science studies and
development of materials conducive to deployment in the fusion
environment; materials tests using fission reactor irradiation; a
materials test station to allow initial tests of small materials
samples under intense energetic neutron bombardment; small-scale
supporting test facilities as needed; and computational modeling of the
integrated fusion system.
This effort should culminate in a national integrated fusion
nuclear science test facility as the central fusion experimental
facility in the U.S. It will provide the needed integrated tests and
development of our understanding of the coupled plasma-wall-energy
conversion systems. While the actual form that the fusion nuclear
science test facility takes will depend on detailed development of its
mission requirements and comparison of competing concepts, this next
major confinement experiment in the U.S. should be a DT (deuterium-
tritium) facility to access the full range of fusion nuclear issues.
Such a facility would likely attract a substantial investment from
other countries should the U.S. seek to lead this effort and pursue
such partnerships. A phased development of the capabilities of this
experiment will restrain costs and coincidently mitigate the impacts of
our off-shoring our abilities to address the first two fusion
challenges above.
The transition of the domestic program elements from the present
configuration to one including the second two fusion challenges is
required. It is important to recognize that this transition will take
time, both to bring existing activities to successful closure and
transition people and resources to new directions. Generally, the
transition can be executed over the next decade or so, concurrent with
the construction and initial operation of ITER.
As the ITER construction winds down, those roll-off funds should be
applied to the new national facility to meet the challenges I have
mentioned above. Some augmentation of those funds will be required to
support a full DT implementation, but foreign collaborations might be
solicited to help make up this gap.
To prepare moving in this direction, the planning of scientific
programs and conceptual designs of requisite facilities to match chosen
scientific missions must begin immediately. These will inform decisions
needed in a few years. In the meantime, the near-term activities of the
program will center on completing missions for existing facilities and
programs as needed to begin a wedge of growth of a Fusion Nuclear
Science Program component to the U.S. fusion program. There is
especially an immediate need for initiating related materials research
and developing trained fusion engineering science personnel.
Executing this transition of the program, and eventually deploying
an integrated fusion nuclear science experiment, would vault the U.S.
program into leadership of critical areas of the overall fusion
challenge. In the ITER era, the research activities on ITER and this
U.S. program would arguably define the centers of gravity of fusion
science and engineering development, and will expedite the decision on
proceeding to the development of a demonstration fusion reactor,
whether by the U.S. Government, industry, or some combination thereof.
There are substantial risks to pursuing this program, and they must
be recognized and managed. There is a real potential for loss of
expertise and momentum as major U.S. facilities roll off and
international collaboration becomes the norm for access to leadership-
class facilities. If all or almost all of the major confinement
experiments in the U.S. were terminated well before a new national
experiment was initiated, there would likely be a loss of specialized
machine designers. This in turn would make it increasingly difficult to
start world-class programs in the U.S. as the international community
moves forward. This has already happened in individual laboratories in
the fusion community.
There is the danger of loss of interest by new young scientists
without world-class U.S. facilities while waiting for a new national
facility. There will inevitably be displacement of personnel, and long-
term planning and scheduling will be required so that scientists and
engineers know what is coming and can adjust accordingly. These changes
will not necessarily be welcomed by the research community because they
will almost inevitably include some reduction of the activities
presently being pursued, and everyone can legitimately claim there is
much more to do in any given area. Indeed, an additional risk is that
many underlying science issues will receive less emphasis than may be
called for. Finally, there is the risk that collaborations with U.S.
scientists may be seen to be less valuable to foreign hosts when the
U.S. has a decreasing number of world-class facilities and likely some
declining domestic research capabilities.
These are serious consequences to a vital research program, and
they are not suggested casually. They follow directly from the funding
levels expected for the program and the scientific demands of the
fusion enterprise. The program could be fatally damaged if these
transitions are not managed adroitly.
However, there are corresponding risks to not evolving from the
present program while our international partners and competitors
aggressively advance their programs. We will either further, or
possibly indefinitely, delay a decision on developing fusion energy. We
would not be competitive as fusion energy and it commercial
applications are developed elsewhere.
Thus, the program must focus and move forward to make the case for
a breakout into a fusion energy development program as soon as it can.
To that end, it may be useful to develop a technical contract among the
fusion research community and DOE managers to define what minimal
knowledge base is needed to establish the credibility of fusion and
then confront the question of whether society wants to make the next
level of investment for the development of commercial fusion energy.
This contract should reflect the views of energy policy professionals
on the criteria for the credibility of fusion as an energy source.
A COMMENT ON INERTIAL FUSION ENERGY RESEARCH
This discussion has focused on the direction of the magnetic
confinement fusion research, given its prominence in the present OFES
program. As mentioned earlier, the campaign to demonstrate ignition of
fusion plasmas via inertial confinement with laser compression of solid
fuel pellets on the National Ignition Facility is imminent. At present,
there is no established program in the U.S. with a focus on developing
the science and technology of inertial fusion energy (IFE). There is a
modest research program in the related area of High Energy Density
Physics, but it is quite broad and addresses some points of interest to
IFE.
The achievement of ignition in NIF will be exciting and historic.
It will rightly demand a reassessment of our national position on IFE.
When ignition is demonstrated, there naturally will be increased
interest in this approach to fusion production as an energy source.
However, the challenges expected to move from this accomplishment to an
energy source are as at least comparable to those in the magnetic
fusion approach. While first concentrating on increasing the fusion
gain to levels of interest to energy production, the issues of target
development, laser development, and fusion chamber development will
rise in interest. In addition, many of the materials and nuclear
science issues to be addressed in the proposed fusion nuclear science
program are common to both approaches to fusion energy.
As the ideas for moving forward towards an IFE program evolve after
data is obtained from NIF, it would be valuable to have a disinterested
expert panel evaluate the prospects and requirements for inertial
fusion energy to inform any decision to embark on an inertial fusion
science program or an inertial fusion energy development program.
SUMMARY
Significant progress in fusion science has been made in the past
decade, and a solid scientific basis now exists to plan towards a
fusion energy mission. The recognition that magnetic fusion energy
research is at a mature stage for exploring burning plasmas and the
expected achievement of high fusion gain in NIF for inertial fusion
energy presage new eras for fusion research and development.
There is a pressing need to broaden the range of fusion research in
the U.S. to prepare to explore the new frontier of fusion science,
i.e., the integrated plasma-chamber-energy conversion system. To
address this issue and position the U.S. as a world-leading source of
expertise in the developing and harnessing of fusion power in the post-
ITER era, it is timely to begin building a fusion nuclear science
program. This will complement the advances made in magnetic confinement
plasma sciences. It will start with modest activities in materials
research and development of a new cadre of fusion engineers, and
progress to the deployment of a new national fusion science research
facility as the cornerstone of the U.S. fusion experimental effort in
magnetic fusion.
The transition to these new efforts should be gradual and supported
during ITER construction in large part by completing existing programs
and out-sourcing many of our near-term activities to new facilities and
programs presently being developed in partner states. Strategic plans
should be developed to map the next decade or more to point to the
initiation of a national fusion nuclear science test facility and to
map the present fusion science program to a future fusion energy
development program, with priority given to expediting that transition.
This will necessarily be a very focused program, and hence contain
risks of disrupting the existing infrastructure and missing other
profitable avenues of research and development.
The highly anticipated success of the ignition campaign on NIF will
rightly increase interest in evaluating the potential of inertially
confined plasmas for energy applications, and should motivate a high-
level review of proposals for a new program in IFE science and/or
engineering.
Finally, support of the H.R. 3177, the Fusion Engineering Science
and Fusion Energy Planning Act of 2009, would provide a modest level of
funding to start this transformation in the program.
Biography for Raymond J. Fonck
Raymond John Fonck is a professor in the Department of Engineering
Physics and the Steenbock Professor in the Physical Sciences at the
University of Wisconsin-Madison. He received his Ph.D. in Physics from
the University of Wisconsin-Madison in 1978 (atomic physics and laser
spectroscopy). He has been involved in fusion energy science research
for almost 30 years in the university and at national laboratories. He
has also been involved in fusion science research policy, serving in
several capacities for national advisory committees and for committees
of the National Academies of Sciences and Engineering. He recently
served as Associate Director of the DOE Office of Science for Fusion
Energy Sciences.
Specifically, he was at the Princeton University Plasma Physics
Laboratory from 1978 through 1989, where he was Deputy Head of the PBX-
M Tokamak project and head of the spectroscopy group on the TFTR
experimental team. He joined the Department of Nuclear Engineering and
Engineering Physics at Wisconsin in 1989. He headed the Pegasus
Toroidal Experiment and directed collaborative experiments on the DIII-
D National Fusion Facility. He is a Fellow of the American Physical
Society (APS), and served as President of the University Fusion
Association for 1999-2000. He was chair of the Organizing Committee for
the 2002 APS Topical Conference on High Temperature Plasma Diagnostics,
and has served on APS Division of Plasma Physics organizing committees.
He has served as a member of the Executive Committee of the Division of
Plasma Physics. He has been a member of several Program Advisory
Committees for large fusion science experiments, and is presently Chair
of the Fusion Simulation Program Advisory Committee. He served on the
Fusion Energy Sciences Advisory Committee sub-panel for U.S.
participation in ITER. He also was a member on the Fusion Science
Assessment Committee of the National Academies' National Research
Council (NRC), and was co-chair of the NRC Burning Plasma Assessment
Committee. He was a member of the NRC Board on Physics and Astronomy
from 2003 to 2007, and was appointed a National Associate of the
National Research Council of the National Academies in 2008. He
presently is a member of the Fusion Advisory Board of the United
Kingdom. Recently, he served as Associate Director of the Fusion Energy
Sciences Program of the U.S. Department of Energy Office of Science. In
that role, he led the fusion science program as it moves to exploring
the burning plasma regime in the ITER international experiment. The
program also supports investigations of magnetically confined plasmas,
basic plasma science, high energy density laboratory physics, and
fusion engineering sciences. Prior to his appointment to DOE, he was
serving as the Director of the U.S. Burning Plasma Organization and
Chief Scientist of the ITER Project Office. His research has been in
experimental studies of high-pressure plasmas in toroidal geometries,
plasma turbulence, and high-temperature plasma diagnostic development.
He was awarded the 1999 APS Award for Excellence in Plasma Physics
Research for his work on measurements of turbulence in high temperature
plasmas. He was also awarded the Fusion Power Associates 2004 Fusion
Leadership Award. He is the author of over 180 articles in publications
on plasma turbulence, plasma confinement and stability, atomic physics,
applied optics, and plasma measurement techniques.
Discussion
Chairman Baird. I thank all the panelists for not only your
testimony today but for your very distinguished careers and
your service to our country as scientists, and I want to ask a
number of questions and will recognize myself for five minutes
to do so.
I want to put my questions into context. The context is
known, and I often mention it regardless of the topic of this
hearing, but it is worth putting forward. The hearing is in the
context of a time when our country faces an $11 trillion debt,
a $1.4 trillion deficit over the last fiscal year. That is our
fiscal situation. Our energy situation is that we, if as I
believe the evidence is compelling that we face global
overheating and acidification of our oceans, the pace at which
we need to make significant cuts in CO2 and other
greenhouse gases is much more rapid than any of the proposals
currently moving through the Congress, and I think more
ambitious than any of the proposals in terms of our reduction
of greenhouse gases. That puts a budgetary constraint and a
timeline constraint, and so with that as context, let me ask a
series of questions so I can understand the sort of timeframe
we are dealing with.
How Fusion Energy Becomes a Usable Resource
Just first of all, how--when we speak of ignition, which I
understand is when more energy is put out than put in, in
layman's terms, what is the longest period of ignition achieved
so far in any of our modalities in terms of time, how much
time?
Dr. Synakowski. Today actually no plasma has ignited. We
have had plasmas with controlled fusion reactions. An analog I
like to use is that it has been like burning wet wood. We have
created a fire, we have controlled the fire, when we take away
the external flame, the fire goes out.
Chairman Baird. Okay. Let us suppose we achieve ignition,
so the challenge, I think once ignition is achieved--this is
not an easy thing and you folks have dedicated your careers as
brilliant as you are to this, and many others before you and I
am sure after. So once we--if and when we actually achieve
ignition, that is a eureka moment in a way but it is not like
all our problems are solved because now we have got more energy
coming out. The challenge is capturing that energy. You have
got to somehow capture it. My understanding is that, and
correct me if I am wrong, and this is not meant in any way
pejoratively, but basically the way we are going to actually
capture that energy is the good old-fashioned way of making
water hot and turning turbines. Is that the model we are doing?
And it is really great that we are still doing steam engines. I
just love this. I don't mean that critically but it just kind
of blows your mind that we are going to all this trouble to
heat water up.
Dr. Synakowski. It is a remarkable thing to go from E =
MC2 to boiling water in a turbine. That is
essentially the train you are talking about.
Chairman Baird. So it is really important for this
committee and I think for Americans and taxpayers to understand
that just because we get ignition doesn't mean we can now
expect that oh, then next week we are going to turn the lights
on with energy produced by fusion energy, right? We have got to
somehow then find a way to actually harness that energy, and
the current model is again through steam-driven turbines,
right? Is that--Dr. Betti?
Dr. Betti. Yes, but there are two aspects. Ignition will
prove the physics of fusion. Making energy after ignition
requires the development of the technology, and often the
development of the technology is faster than development of the
physics. So that is why it is so hard, because we haven't
proved the physics yet, and then we count on the technology to
move a lot faster and turn the physics success into making
electricity.
Chairman Baird. But there are some real challenges there,
in terms of----
Dr. Betti. Major challenges.
Chairman Baird. The material science of what kind of
material can contain these reactions and sustain the
bombardment of the neutrons, et cetera, right? And then so we
have got some challenges ahead. Dr. Prager.
Dr. Prager. I think you are exactly correct, and a lot of
the suggestions you have been hearing from the panel members
get exactly at the questions you are pointing out need to be
resolved. How one harnesses the fusion power is sometimes the
expression used. So there are ideas to set up a research
program to deal exactly with that question in addition to the
remaining physics questions.
Potential Consumer Prices for Fusion Energy
Chairman Baird. Then there is the next question. Okay, so
let us suppose theoretically we can do it. We have solved the
physics problem. We demonstrate that ignition is possible. We
contain it with magnetic fields. We heat the water up. Then
there is this little nagging problem of cost per kilowatt-hour.
This seems to be a bit of a challenge. Any thoughts about cost
per kilowatt-hour?
Dr. Mason. I don't want to offer up a number but I would
sort of characterize it a little bit in the sense that with
fusion the--you know, no one is talking about electricity too
cheap to meter. I think everyone has learned the lesson that
you shouldn't confuse fuel cost with what things actually cost.
Fusion will be a fuel source that is dominated by capital costs
because there is no ongoing substantial fuel cost, and of
course, capital costs have to do with financing models and
lifetimes and things that go well beyond the realm of physics
and engineering. But if you look at the scale of plants that
are being contemplated and the complexity of them, I would say
it is not fundamentally different than the kind of cost model
you see associated with fission. And what we have seen is that
fission power is actually very cost-competitive, but because of
the large upfront capital costs, it is difficult for risk
markets to handle, and that is why things like the loan
guarantee programs and so forth are very important. And so I
think with the right sort of policy framework, it can be very
cost-competitive, understanding that things like the programs
that are in place now that are hopefully going to get us going
with new starts in fission are likely models that would have to
be explored, particularly at the outset when the risk is much
higher.
Fusion as an Alternative to Other Energy Sources
Chairman Baird. Which leads to the question, you know, for
me one of the challenges we face is, we have this imminent
problem of global overheating and ocean acidification. We have
this tremendous budget debt and deficit right now, and we have
alternative technologies that today you can buy off the shelf
that produce net energy output with the existing fusion energy
thing called the sun at a known kilowatt-per-hour generation
that if you invest, you know, with money being both finite and
fungible, if we invest X amount of dollars now, we can lower
our carbon output, et cetera. And so I think it is just really
important for us to understand the win of this. So I have been
talking costs and how and stuff. The win seems to me to be a
good bit down the road. By win, when I say win, we could
actually generate significant replacement of existing energy
sources. I would be shocked if any of you would say less than
20 years and I guess it is more like 50. I may be wrong.
Dr. Mason. I alluded to this a bit when I talked about the
portfolio of energy choices, and I would kind of divide it into
three categories. In the very near-term, the most fruitful
sorts of investments we can make are in energy efficiency.
There are a lot of things that we know how to do that can
immediately reduce demand, and the cheapest form of energy is
the energy you don't need. In fact, most of the energy
efficiency steps which represent about a third of what you need
to achieve the types of CO2 emissions that people
are talking about cost you a negative amount of money. In other
words, you save money by doing it. And so there is no question
in the very near-term that is the low-hanging fruit that we
need to go after aggressively. Things like renewables, wind and
solar are--we know we can make them work but they are not yet
cost-effective, although there are a lot of promising research
directions that will improve that. And scaling up will bring
down the cost. But these are intermittent, and so certainly
when the sun is shining and the wind is blowing, we will want
to be harnessing that energy and the environmental benefit that
goes with it, but it is not a baseload generating capacity. We
do need baseload capacity that we know will be on when people
switch on the light switch and will allow us to buffer the
intermittent renewables, and fusion has the possibility to
offer a baseload generating capacity that does not have a fuel
constraint. Right now most of our baseload capacity comes from
coal, and in terms of timeline and risk, I would say our
chances of being able to sequester CO2 from coal-
fired plants at the scale we need to is not greatly different
from the challenge we face in fusion.
Chairman Baird. I don't dispute that.
Dr. Mason. And we can't be sure that either one will work.
Chairman Baird. I think that is a good point.
My time is up, past up, but I wanted to establish that line
of evidence and questioning, and Mr. Inglis is recognized for
five minutes.
Mr. Inglis. Thank you, Mr. Chairman.
Arguments for Promoting Fusion Research
I wonder if others on the panel agree with Dr. Mason's
assessment, that fusion is in the league of fission in terms of
the capital costs and the involvement that we would have. Do
you agree with that, Dr. Prager?
Dr. Prager. Yes, I would. One of the guiding principles,
almost too much so, of the fusion program over the decades has
been economic attractiveness. It has guided the kinds of
plasmas we try to produce and has set goals for us, and
throughout the years there have been many, many system studies
of fusion systems in the future that as best can be done assess
the cost, and the cost of electricity comes out to be
competitive. There is a big ``however.'' Those studies assume
certain success in physics and technology so assuming that the
physics and the technology research missions are accomplished,
then they calculate that the costs are competitive. So I think
what Dr. Mason says has been backed up by studies, and another
caveat is of course when you try to project the cost of
anything several decades into the future, it is fairly
theoretical.
Mr. Inglis. Does anybody else want to comment about that,
about equivalency between the--are we in the ballpark of a
fission kind of investment when we go to fusion if we make
electricity that way?
Dr. Fonck. I will just back up what Dr. Prager said. There
have been a lot of studies, and the answer is generally yes,
these are large power plants. These are multi-gigawatt power
plants typically to get the most efficiency out, and so you are
in that ballpark in terms of the scale of the plant. Of course,
the issues are different. Fission and fusion are quite
different so the radioactive materials and the things you have
to worry about are quite different, but the magnitude of the
plant is about the same.
Mr. Inglis. Let me make sure I understand that. What is the
difference in terms of radioactivity in that?
Dr. Fonck. Well, fusion works with just deuterium and
tritium. Tritium is just a gaseous fuel. There is not a lot in
the plant and the radioactive waste you produce in fusion is
mainly the structure that holds the plasma. There is no long-
term highly radioactive waste that you get in a fission plant.
Now, the fission people have ways to, if we ever get there, to
transmute those wastes. But at the moment you are looking at
very long-term, hundreds of thousands of years kinds of waste.
Fusion doesn't have that. It has essentially a short-lived,
hundreds of years, waste issue. You can imagine that, in a
generation or two, it would decay away. And so it is a
different radioactive profile. And that is one of the big
advantages of fusion.
Mr. Inglis. What are the other advantages? Why should the
United States pursue fusion?
Dr. Fonck. I will throw in a few, and I am sure everybody
else has their favorite. Well, there is one. The other of
course is the ready availability of fuel. It is right out of
seawater. All you need is deuterium and lithium. Lithium breeds
the tritium. There is no danger of catastrophic failure of a
fusion plant. The plasma state is essentially quite fragile. If
anything happens, you get a leak in the chamber or something
like that, the system just extinguishes itself. So it is quite
safe, passively safe, if you will. The other thing of course is
that it can be anywhere. It is a baseload energy source. I
think to back up what Dr. Mason said, if you look into the
future, not myself but energy experts, you only see two or
three baseload possibilities in the future and it is fusion,
fission, if you want to be carbon-free, of course, and possibly
solar with storage, but that is a very hard proposition.
Mr. Inglis. Anybody else want to add a reason to pursue
fusion?
Dr. Betti. I concur with my colleagues on both issues. In
relation to your question, yes, fusion is clean and the fuel is
basically unlimited. In the case of deuterium-tritium fuel is
only limited by the supply of lithium. Of course, deuterium is
abundant in seawater and it is unlimited. On the issue of cost,
there have been several studies both about magnetic fusion
energy power plants and inertial fusion energy. There have more
studies on magnetic side than inertial side. The United States
had a program until last year, the High Average Power Lasers
Program, that were developing the technology of an inertial
fusion energy- based power plant and so they were doing
technology development, the cost estimates of this sort. To the
best of my knowledge, the cost is competitive with fission-
based nuclear power.
Dr. Mason. I would offer as an attribute of fusion that I
think we in the United States should find attractive, the
comment that I made about, you know, we talked about the fuel
but another way to look at the fuel for fusion is that it is
intellectual property and high-end manufacturing. The fuel is
not something that you import from the Middle East. It is not
something that you run out of and it is actually the essence of
what our economy is built around, which is smart people and
competitive industry, and so not only as a domestic supply of
energy but as a possibly significant export market. If we can
position our industry to lead in this field, there would be, I
think, economic value for the United States.
Dr. Prager. Just getting into maybe a softer reason, since
the fuel comes from the ocean's water and that should be
accessible to all nations and you might speculate that the
conflict over natural resources for energy between nations
would be decreased with fusion driving the energy sector. So
that is another reason. I mean, it is interesting, when most of
us entered the field, what drew us in in terms of the
application was that we were running out of energy. In the
1970s we were running out of energy, there were gas lines, an
energy crisis, and now perhaps really what drives it, the
dominant reason probably is no contribution to global climate
change. So fusion somehow is almost the ideal and the
dominating reason maybe just changes with the times as the
problems that we confront become more clear.
Mr. Inglis. Thank you.
Thank you, Mr. Chairman.
Chairman Baird. Dr. Ehlers.
National Security and Technical Elements of Plasmas in Reactors
Mr. Ehlers. Thank you, Mr. Chairman. Unfortunately, all the
good questions have been asked already. But let me add one
other item to our list, Dr. Prager, and that is national
security. We are treading very tenderly in some treacherous
waters with our current energy policies, and I really suspect
that far too many people who should know that don't know it,
and I am not just talking about gas lines, I am talking about
the whip that other nations can hold over our nation just
because we do not have the energy resources that we would like
to have, and it continues to concern me. There are endless
conversations that I get into both inside and outside the
Congress. People say oh, well, you know, we have these new
sources of natural gas, and in Pennsylvania we can get this new
gas, we are all set for years and years and years. Yes, we are
set for years but not years and years. And this inability to
deal with reality is just fascinating to me. People just assume
that somehow the scientists, the physicists, the engineers will
find a way out of these shortages. And I have taken the
opposite point of view. I have often said that natural gas is
too valuable to burn. It is an incredibly useful feedstock for
the petrochemical industry. I don't know of anything that is
going to be as easy and cheap to use, and we are burning it. So
there is a multitude of issues here, not just energy issues but
resource issues, security issues, et cetera, and I don't think
that we as a Nation are confronting them as adequately as we
should. Having said that, I do wonder--I am just asking
questions, things that I really haven't kept up with the field
at all. How are we going to contain the plasmas and how easy or
how difficult is that going to be to actually extract useful
energy out of a fusion reactor? And I know it depends on the
different types of reactors but can one or more of you just
give me a quick summary of where you see this field going?
Dr. Synakowski. That is a great and deep question. I think
we have many elements of the solutions to both questions in
hand, a much more mature understanding with respect to how are
we going to contain the plasma and control it. There has been
tremendous progress since actually the late 1960s, when there
was a transformative event in the invention of the tokamak,
which is a kind of magnetic bottle, if you will. It's twirly
shaped. Just a little bit of science here. The plasma, if you
can imagine a donut-shaped magnetic field, this is the heart of
magnetic fusion with the plasma which is charged particles,
ions and electrons. They do a very good job of moving along the
magnetic field lines but have a very tough time crossing the
magnetic field lines. But there are lots of subsidiary
processes that go on in the plasma that can force the plasma,
the hot fuel to make that migration across the magnetic field.
What you are trying to do with that magnetic field is confine
it for long enough so that you can heat it rapidly to get up to
fusion conditions where the plasma pressure is such that the
fusion between the nuclei takes place.
What has happened as the United States has really turned
towards the science of the plasma I think has been a tremendous
set of advances in understanding the basic physics of how the
plasma is confined in this magnetic bottle, and what levers we
can apply to the plasma to optimize that confinement. And I
want to make two points. One, this is a very deep intellectual
exercise, which is I think worthy of investment to obtain U.S.
capital. These are great scientific challenges but they are not
empty challenges, they are the best kind. They are the ones
that are directed towards a purpose because the answers that we
are finding with respect to the science, for example, of
optimizing the confinement in this magnetic field, enables one
perhaps to make a fusion reactor smaller which enables then for
the vision of a fusion reactor to be more economically
attractive. The science is intimately linked to the final
product and so I think for those who are interested more
directly in the final product, it is a compelling enterprise.
The United States aesthetic I think has been extremely strong
in terms of understanding that plasma science. It has been
emphasized here though we think a major frontier resides in
crossing that bridge from that magnetic bottle to boiling the
water and generating the steam, and that is the material
science question and the challenge of harnessing a fusion
power.
And just as a footnote to all of this, a significant
alternate approach that has been mentioned, especially by Dr.
Betti, is that of inertial fusion. It is a fundamentally
different process where you take a small pellet of fusion fuel.
There are no magnetic fields in most versions of the vision.
And you compress it very suddenly on relying on the inertia of
the fuel itself to kind of tame itself long enough for the
fusion to take place. But external to that, the transition to
the fusion power and getting the power on the grid looks quite
similar. Both of them again represent very deep scientific
challenges but again I think they are the best kind of
scientific challenges because they have direct bearing on the
output and the attractiveness.
Mr. Ehlers. Thank you.
Dr. Mason. I could maybe add a little bit about the
materials because I think that is a very important aspect is
how you transition from the environment where fusion is
happening, whatever form of containment you have and the
environment where you are, you know, holding a vacuum and
boiling water and so forth. It is a very challenging materials
problem that falls into the general category that we like to
refer to as materials under extreme conditions, and fusion is
perhaps the most extreme of extreme conditions in terms of the
temperatures, the radiation damage that the material is
subjected to, the presence of hydrogen and the effect that it
can have on materials. My background is materials science, so
while I can't say too much in depth about fusion, in terms of
materials, these are difficult problems, and they are a
different sort of problem than some of the areas that we focus
on right now. We at Oak Ridge and around the world are very
excited about nanotechnology and things we can do with that and
thin films for photovoltaics. The materials we are talking
about here are different types of steel. It is the materials of
heavy industry, and to be honest, the development of new steels
is not something that as a nation we have been doing a lot of
in recent times. In fact, you know, many of the materials we
have now were developed decades or even in some cases centuries
ago. They have served us very well, but they don't necessarily
have the characteristics to survive under the conditions that
we need, and that is why many of us have talked about the need
to look at these materials issues, even as we resolve the
remaining physics questions of the plasma, and many of those
materials issues are the same whether it is inertial or
magnetic confinement. In some cases, they may even be the same
or similar to those faced by fast reactors that might be used
in closing the fuel cycle. It is maybe not as sexy as
nanoscience but getting better alloys is an important part of
this equation.
Mr. Ehlers. Thank you very much. I would like to move on.
Chairman Baird. I know Dr. Fonck and others want to add but
I want to recognize Dr. Bartlett for his line of questions.
Fusion vs. Wind and Solar Energy
Mr. Bartlett. Thank you very much. Whether or not we are
successful in getting fusion power, and I am skeptical, I am
still enormously supportive of this work because I think that
we may find a lot of very other interesting things as we pursue
this leading edge of scientific inquiries.
Dr. Mason, you mentioned efficiency as a major interest. I
would like to suggest that before efficiency we can get huge
gains from conservation. Conversation is two people getting in
a car instead of one. Efficiency is getting in a Prius instead
of an SUV. And we have enormous opportunities for gains in
conservation, which could be immediate and free, really, really
simple. You know, we have a huge reactor in the sun and I know
that we disparage the use of solar and wind as baseload but I
think it would be less technically challenging to make that
baseload than it would be to produce fusion power. Wherever you
have a topography difference, doesn't pump storage work very
well for storing the excess energy you have when the wind is
blowing and the sun is shining? And I suspect that creating
huge banks of capacitors or enormous flywheels would be
technically easier to do than trying to do what we are doing
with fusion. By the way, I am a huge supporter. If the
capability were out there, two and three times the amount of
money that we appropriate for that, I would be happy to
recommend that to the appropriators. But aren't there enormous
opportunities for making solar and wind baseload?
Dr. Mason. Energy storage has huge leverage. If we could
store even a small fraction of the grid for 24 hours, it
would----
Mr. Bartlett. You can store it all in pump storage, sir.
Just pump it up to the mountain and a lake up there and then
run it down when the sun is not shining, wind is not blowing
through a turbine. It is really simple.
Dr. Mason. And in fact, in Tennessee TVA has something
called Raccoon Mountain where they do exactly that, so it does
work, but if you look at the capacity and efficiency of it, it
is hard to see it scaling to the level that we would need. Now,
if you push renewables as we should, you can probably get up to
about 20 percent and still handle the intermittency. And you
could push that farther if you had better energy storage,
whether it is electrical energy storage in the form of
batteries or compressed air. So I think there is tremendous
leverage in storage. It is an area we should be and are
investigating. But on grid scales, I believe it is a very
challenging problem, and it is one that is maybe not quite as
difficult as fusion but it is in the same league.
Electrifying Transportation
Mr. Bartlett. Dr. Betti, you mentioned something else that
I think most people don't understand. You said that we should
be electrifying our transportation, and you know, we use two
kinds of energy. One is electrical energy, and I think the
future for electrical energy is okay with nuclear, whether it
is fission or fusion, with wind, with solar, with microhydro,
for which there is considerable potential, and for true
geothermal where we are tapping into the molten core of the
Earth, I think that we can make about as much electricity as we
ought to be using. But it is not true for liquid fuels because
there is just no combination of substitutes out there for
liquid fuels, and when gas and oil and coal are gone, and they
will be, we are going to be living on electrical energy and so
I think that too few appreciate the concern that you have that
we need to be electrifying transportation because that is one
essential use of liquid fuels. Some of the use of liquid fuels
we can use electricity for, but for that one now, it is tough.
We just tore up all our streetcars. We were proud that we were
doing away with these antique things and we tore them all up.
Now we need to be putting them back. Thank you for your
recognition that we need to be doing that.
I welcome a second line of questioning, Mr. Chairman. I
yield back.
Chairman Baird. Thank you, Dr. Bartlett. It looks like we
are all going to probably not be able to do the second line
with the votes being called, so I recognize Dr. Rohrabacher--
Mr. Rohrabacher.
Mr. Rohrabacher. Dr. Rohrabacher. That was quite a----
Chairman Baird. It is a frightening thought.
Skeptical Arguments
Mr. Rohrabacher. Let me just note, Mr. Chairman, that we
heard that before back in the 1970s. We saw the gas lines and
we were told that there was an imminent situation where there
would be this massive shortage of energy and that was proven
false, and now we are using an excuse of greenhouse gases which
will cause global warming as an excuse to move forward on
certain things, and quite frankly, none of the predictions of
those people who have been advocating global warming have come
true. In the last nine years there has been cooling, and in
fact, there are now reports that the polar ice cap, the one
pole or the other--the Antarctic was never contracting but the
polar ice caps are now expanding. So this idea of greenhouse
gases causing global warming is the basis of a lot of things
but I would not use it if I was in the scientific community as
an excuse for moving forward with fusion energy research
because that I think is becoming something that again is
another theory that will be proven false and it is being proven
false by the way the world is acting.
When I was a young child, and I was actually in I think
fifth or sixth grade, I saw a wonderful movie about fusion
energy, and Mr. Science, I don't know if you remember those
things, it was wonderful, and fusion energy was the energy of
the future, and you know what? I am 62 years old now and I take
it from what you have told us today that we haven't even had
ignition yet after all of these years of research, and my
calculation is that we have had $40 billion worth of research
and we don't have ignition yet. Dr. Bartlett's observation is
that research money--there is limited research money in this
country--might well be put to better use in finding out how we
can utilize the heat from the core of the Earth or the pumping
technologies.
Mr. Bartlett. I want to do both.
Mr. Rohrabacher. Both. I do too. But we have limited
research dollars. Why is it that fusion after all of these
years and all of this money and with so little actual progress,
meaning we haven't even had ignition yet, even for a second, I
believe, why should we continue? Why shouldn't we transfer this
money to some of these other technologies that perhaps would be
cheaper? And one last thought, Mr. Chairman, and that is--and
then I would like the panel to go to that question--and that
is, I do believe that we should have at least one skeptic on
the panel for every subject that we look at, and it is okay, I
mean, all of you gentlemen have incredible credentials, a lot
more than I do, that is for sure. But some of the issues that I
am raising should be raised by people who have got Ph.D.s in
this and be able to have a dialogue so that we will have
something to decide here on the panel rather than just
accepting one point of view.
I have made a couple points. Please feel free. I know you
have got some things to counter there.\1\
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\1\ See response from Dr. Prager in Appendix.
---------------------------------------------------------------------------
Dr. Synakowski. If I may, I think there are probably many
facets that people might comment on. I think--actually I have a
view that the urgent things and the opportunity we have is in
fact to address the questions of credibility that you raise.
Our science basis is such that I believe we have good
confidence in what is required of our next step to get to the
stage of what we call burning plasmas in magnetic fusion. I
think that is what you are referring to when you are talking
about ignition, where we are getting more energy out than we
are putting in to heat it and control it. I think our
understanding, the scientific basis for getting there is quite
strong. And we understand it, and I will oversimplify it a
little bit by saying it is a question of scale. We understand
that the present devices that we have invested in are not
appropriately scaled and don't have the control technologies
that we need to reach the scientific regime that you are
talking about. Having said that, in the early part of, I think
it was in 2001, there was a technical assessment of several
options in magnetic fusion that we could pursue to
understanding this burning plasma state.
Also with respect to credibility, I think if you burrow
down one more level, you get to the question that people had
been raising here, and that is the question of materials and
harnessing these fusion plasmas. I would be delighted, I would
view it as a major accomplishment collectively in our careers
to be able to point quite definitively to the answers to your
questions demonstrably. I believe the scientific understanding
is strong, that we have a confident and strong bridge to the
demonstrations that you are talking about. Understand also that
publicly there are many who desire exactly the sort of thing
that you are talking about. I think we are in reach of doing
that.
Mr. Rohrabacher. Well, I have supported nanotechnology and
these things, and I do support them, but they take research
money, and we have had $40 billion eaten up for fusion that
perhaps had we put into nanotechnology or some of the other
more that we have some actually demonstrations of progress,
perhaps some of the other issues you are dealing with would
have been solved.
Chairman Baird. My colleagues, we now have about eight and
a half minutes left to vote, and what I would like to do is, I
think rather than asking these gentlemen to wait 40-plus
minutes while we go vote and come back and sometimes don't come
back, what I would like to do is close, but Dr. Bartlett had
some questions earlier that I know folks wanted to respond to.
I would invite the witnesses, if you have additional responses,
I know there some eyebrows raised about whether $40 billion is
the correct number that has been spent, please feel free to
give us some written comment.\2\
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\2\ See response from Dr. Prager in Appendix.
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A Federal Agency Home for Inertial Fusion Research
I would just like to close with two questions. I want to
make sure we get one issue on the record real quickly. My
understanding is that the inertial fusion energy effort is, I
am not sure the proper way to say it but does not necessarily
have an official home within either NNSA or the Office of
Science Research, and I am wondering is that is something we
ought to consider addressing. I will give you a couple minutes.
We are down to about seven minutes to get over to the vote. So
any brief comments. Dr. Betti, you are in charge of that
operation.
Mr. Betti. Yes. So first I should just really briefly
mention the fact that the physics principles of inertial fusion
energy, what we call ignition, has actually already been
demonstrated because that is how hydrogen bombs work. Okay. The
problem is that to trigger ignition in hydrogen bombs----
Chairman Baird. It is a hell of a way to heat your house.
Dr. Betti. We use an atomic bomb. No, but this is
important. We use an atomic bomb. So what we are trying to do
is to replace the atomic bombs with a driver, a laser, okay,
but the physics principles have been demonstrated. What hasn't
been demonstrated is that we can reproduce this in a
laboratory. So that is an important distinction. In terms of
the inertial fusion not having a home, inertial fusion energy
doesn't have a home. Inertial fusion does have a home in NNSA
for weapons----
Chairman Baird. Good point.
Dr. Betti. Okay. So it is very important, I think, and very
cost-effective to use the facilities that have already been
built by the National Nuclear Security Administration for
billions of dollars that are already there including the
National Ignition Facility or mega laser and so on. We can use
this to study the energy applications of inertial fusion and so
that is why I think it is critical to have a home for fusion
energy, inertial fusion energy, and use these facilities. We
don't need a lot more facilities.
Chairman Baird. So you have got the physical home in terms
of the infrastructure.
Dr. Betti. The infrastructure.
Chairman Baird. Bureaucratically, where should the home be,
NNSA or DOE, or both?
Fusion as an Unacceptable Substitute for Conservation
Dr. Betti. Well, I mean, this is really not really for me
to answer the question. I mean, I would think that the fusion
energy development program should be within the Office of
Fusion Energy Sciences but that is my personal preference.
Chairman Baird. Let me ask one last question and my
colleagues are ready to go, quick question. If anybody were to
say hey, we don't need to conserve--I want to really put the
punctuation point on Dr. Bartlett's. If someone were to suggest
we don't need to engage in conservation or renewable energy
development because we have got fusion right around the corner,
anybody agree with that at all?
Dr. Mason. I think this is not an either/or. We absolutely
have to conserve and do energy efficiency, but we should not
fool ourselves to think that that by itself will get us----
Chairman Baird. I get that, but it would be foolish to say
that fusion is right is around the corner, it is going to solve
all our energy needs. Mr. Davis is here. I am going to
actually--very quick question. My colleagues are free to head
out. But if you have other questions to ask, we will not be
returning for this panel.
Mr. Davis. Just a comment and question, and Dr. Mason, I
will probably converse with you later today about the question
I am going to ask. There is a great deal of excitement about
when the solar and other renewables being discussed now, if in
fact as some believe that will supply our energy needs, why do
we bother with fusion at all?
Dr. Mason. I think that the challenge is that in order to
get to the sort of goals that I think we a nation have in terms
of energy independence and emissions, we are going to need
renewables, we are going to need storage, we are going to need
baseload carbon-free generating capacity as well. And so we
should certainly be using renewables as much and as quickly as
we can, but they will not scale to meet all of our needs, and
that is where a clean baseload generating capacity like fusion
has the potential to be very valuable as part of our longer-
term R&D portfolio, not to say that we shouldn't be pushing as
hard as we can and as fast as we can on the things that we can
do easily and quickly, like energy efficiency.
Mr. Davis. We get roughly 20 percent from fission nuclear
energy today. What would be a--what would you see as a possible
projection from fusion, nuclear fusion and the research we are
doing?
Dr. Mason. Fusion can play exactly the sort of role in our
electric grid that fission plays today and in fact in the end
fission has a fuel supply need, so in the very long-term
fission would be probably superseded by fusion.
Closing
Chairman Baird. Dr. Ehlers had a final comment.
Mr. Ehlers. I want to thank you for holding the hearing. It
has been very, very useful to me, but I also want to
congratulate you and the panel. I think this is the first
hearing we have had on fusion that didn't result in questions
about cold fusion. So we did have a little bit of disagreement
about climate change but maybe we are making progress here.
Thank you very much.
Chairman Baird. I want to echo Dr. Ehlers' comments. The
frankness and honesty about both the potential and the
limitations and the challenges have been very refreshing and
much appreciated by myself and I think by my colleagues as
well.
I again, thank the witnesses for their time and for their
many years of service, and we look forward to continuing the
dialogue. If you have additional comments, the record will
remain open for two weeks to offer those, and with that, the
hearing stands adjourned. Thank you very much.
[Whereupon, at 11:26 a.m., the Subcommittee was adjourned.]
Appendix 1:
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Answers to Post-Hearing Questions
Responses by Dr. Edmund J. Synakowski, Associate Director for
Fusion Energy Sciences, Office of Science, U.S.
Department of Energy
Questions submitted by Chairman Brian Baird
Trade-offs on building a new large U.S. facility
Q1. LAmong the three major magnetic fusion facilities in the
U.S., the youngest has operated for 10 years and the oldest for
about 25 years. At the same time we have heard testimony from
several of the witnesses for this hearing on the need for a new
large fusion facility in the U.S., parallel to ITER, that can
operate in a nuclear. environment for advanced materials
research. ITER is not designed to fully address this research
area, and you note that it would be critical for a future
fusion power plant. Do you envision. closing down any or all of
the major facilities we have today to achieve these new
capabilities within a realistic budget scenario?
A1. The programs carried out at the existing major facilities
are vigorous and strong; but, like all of our programs, they
are always being evaluated in the context of the evolving needs
of our national program. It is essential that the U.S. assert
leadership in the fusion sciences where we can make fusion
energy 'a reality as soon as possible. We have a clear
understanding of the science and technology issues that must be
resolved. So, upgrade, redirection, or orderly closeout of any
element of our program are always options in maintaining the
research portfolio necessary to make fusion energy a reality as
soon as possible.
Q2. LDo you see a point of diminishing returns for any of these
current facilities on the horizon?
A2. The intellectual return on research performed on the major
U.S. facilities is strong and puts the U.S. in a leadership
position in many aspects of the fusion sciences. We will,
however, continue to monitor these facilities as we go forward
and, as the global fusion research landscape evolves, we will
continue to assess their suitability for continuing to
contribute significantly to fusion energy research.
Inertial fusion energy
Q3. LRight now DOE's National Nuclear Security Administration
(NNSA) stewards all of this country's major inertial fusion
facilities for stockpile stewardship purposes, and your program
within the DOE. Office of Science supports basic science on
high energy density plasmas which may be relevant to inertial
fusion energy. Still, there is no bureaucratic home in the
Federal Government for inertial fusion research specifically
for the purposes of producing energy. Should DOE wait until NIF
achieves ignition to formulate a strategy to address this, or
would it be wiser to have worked out a comprehensive plan and
to have formally initiated a small, early-stage inertial fusion
technology program ahead of such an event in order to
immediately address the research opportunities it provides?
A3. It is reasonable and prudent to explore how inertial fusion
energy research might be most effectively managed ahead of NIF
ignition. While the details of such a plan will depend in
significant part on the results obtained on the path to
ignition, an in-depth strategic analysis of the challenges and
potential of an IFE program would be helpful.
As presently configured, the respective SC and NNSA fusion
offices have different technical strengths and different
missions. Each, however, would play a significant role in IFE
research.
It has been recently proposed that the National Academies
undertake a study regarding the path forward for IFE in the
event of NIF ignition. Such a study should highlight many of
the science and technology issues that need to be addressed for
an IFE program to succeed. This study, and our ongoing
experience in SC/NNSA joint management of the high energy
density laboratory plasma science program will help inform any
future discussions and decisions regarding governance of a
broader IFE science and technology mission.
Q4. LShould the Office of Science or NNSA have the lead role in
advancing this technology for energy?
A4. Both offices have expertise and resources needed to give
inertial fusion energy the best chances of success. The
advisability and governance of a possible future single program
are policy issues that need to be assessed and determined going
forward.
Q5. LIn view of the additional mission built into NNSA's
authorizing legislation ``to support United States leadership
in science and technology,'' would it be more appropriate for
that agency to continue stewarding advanced technologies that
spin out of its weapons program, even if the final application
is energy-related rather than weapons-related?
A5. The production of ignition will itself be a preeminent
demonstration of U.S. leadership in fusion science and
technology. Whether NNSA continues to steward advanced
technologies that are spin-offs from the weapons program is a
policy decision that needs to be fully considered and
determined in the future. The National Academies study noted
above should provide an initial framework for serious
discussion?
Q6. LRecently, in the Conference Report for the Energy and
Water Development Appropriations Act, 2010, DOE was directed to
review an inertial fusion energy research project at the Naval
Research Laboratory and report on its findings within 60 days.
The Conference Report also states: ``The conferees encourage
the Secretary to explore all possible opportunities to ensure
that this program, which offers unique potential for long-term
energy independence, is not abandoned for lack of a
bureaucratic home.'' Please describe the Department of Energy's
plans for this program, and what the impact to inertial fusion
energy research would be if this program were officially
terminated?
A6. A proposal for performing some of the Naval Research
Laboratory work was received in the fall. It was peer reviewed
in a process managed by my office. The proposal for funding was
declined based on this review. The Department of Energy is
currently analyzing the challenges and potential of an inertial
fusion energy program. A proposed National Academies study
should highlight the science and technology issues that need to
be addressed for a successful IFE program.
Small fusion experiments
Q7. LYour office manages an ``Innovative Confinement Concepts''
program that is essentially a collection of small facilities at
universities as well as national laboratories. These facilities
can be grouped into several smaller categories including: basic
science, support of major facilities, and alternative fusion
concepts of varying stages of development. Should all of these
facilities continue to be lumped into a single grant
competition within the Fusion Energy Sciences (FES) program
every few years when their applications can be so different?
Should these facilities be more explicitly aligned with FES's
other more clearly defined subprograms in the budget .process
as appropriate?
A7. As the new Associate Director for the Fusion Energy
Sciences program, I am taking a fresh look at all of our
programs, how they align with our overall mission, and how
proposals are solicited for the Innovative Confinement Concepts
(ICC) subprogram. As an important step, a recent ICC
solicitation issued by my office makes a shift compared to past
ICC calls. The current solicitation calls for proposals that
have demonstrable connections to the science of burning plasmas
in the laboratory, or that can enable this science to advance.
This is appropriate as we enter the burning plasma era. I am
fully committed to nurturing this scale of experiment so that
it has maximum scientific impact both for fusion in particular
and for the plasma and material sciences more generally. Our
Office also understands the inherent benefits of this scale of
research to students in building strong direct experiences with
experimental fusion and plasma science.
Appendix 2:
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Additional Material for the Record
Additional Testimony by
Dr. Stewart C. Prager
Director, Princeton Plasma Physics Laboratory
At the fusion energy hearing on October 29, 2009 Congressman
Rohrabacher raised three important issues that I wish to address
briefly.
First, Congressman Rohrabacher stated that the fusion energy
program has over the years acquired $40B in federal funding. This
statement is incorrect. The total funding provided for fusion energy in
the U.S. since 1953 is $11.5B (as spent) or $16.9B (inflation-adjusted)
[source: S. Dean, Fusion Power Associates]. Current annual funding for
fusion energy of $0.42B is close to, but slightly above the historical
average.
Second, Congressman Rohrabacher asserted that there has been little
progress in fusion energy. My response is confined to magnetic fusion
energy. By any measure, the progress in fusion energy has been
quantitatively enormous. Over the past thirty years, the fusion power
produced in experiments has increased by a factor of 10 million, from
0.1 Watts produced for one-thousandth of a second around 1970 to 15
million Watts produced for seconds currently (see attached graph).
Essentially every relevant scientific measure of progress, such as the
fusion gain, has experienced an equally steady and steep advance. We
routinely produce 100 million degree plasmas, and control them with
unanticipated precision. Underlying this demonstrable and quantitative
progress is the development of a new field of science--plasma physics.
Fusion energy has both required and driven the development of plasma
physics, which has had huge scientific and practical consequences
beyond fusion--from understanding the cosmos to fabricating computer
chips.
Third, Congressman Rohrabacher noted that despite large funding, we
have not yet achieved ignition. For magnetic fusion energy, the
approximate equivalent of ignition is attainment of a burning plasma. A
burning plasma is self-heated by the fusion power itself. ITER will
achieve this goal, as well as continue the advance of fusion power by
producing 500 million Watts of fusion power for long periods of time.
But, an historical note is also important here. About 20 years ago, the
U.S. fusion community proposed an experiment called BPX (the Burning
Plasma Experiment). BPX was endorsed by the DOE Fusion Policy Advisory
Committee, which recommended construction. It was not funded. About 10
years ago, the community produced a design called FIRE, a modern
experimental design for a burning plasma. Its mission and feasibility
were affirmed by the DOE Fusion Energy Sciences Advisory Committee. It
was not funded. Finally, ITER is funded to achieve this long-proposed
goal. Had any of these earlier proposals been realized, we would now be
studying burning plasmas. The scientific knowledge has existed for some
time to achieve this milestone.