[Federal Register Volume 63, Number 2 (Monday, January 5, 1998)]
[Notices]
[Pages 211-219]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-114]
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DEPARTMENT OF ENERGY
Office of Energy Research and Office of Environmental Management
Energy Research Financial Assistance Program Notice 98-08;
Environmental Management Science Program: Research Related to High
Level Radioactive Waste
AGENCY: Office of Energy Research and Office of Environmental
Management. U.S. Department of Energy (DOE).
ACTION: Notice inviting grant applications.
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SUMMARY: The Offices of Energy Research (ER) and Environmental
Management (EM), U.S. Department of Energy, hereby announce their
interest in receiving grant applications for performance of innovative,
fundamental research to support specific activities for high level
radioactive waste; which include, but are not limited to,
characterization and safety, retrieval of tank waste and tank closure,
pretreatment, and waste immobilization and disposal.
DATES: Potential applicants are strongly encouraged to submit a brief
preapplication. All preapplications, referencing Program Notice 98-08,
should be received by DOE by 4:30 P.M. E.S.T., January 27, 1998. A
response encouraging or discouraging a formal application generally
will be communicated to the applicant within three weeks of receipt.
The deadline for receipt of formal applications is 4:30 P.M., E.D.T.,
April 16, 1998, in order to be accepted for merit review and to permit
timely consideration for award in Fiscal Year 1998.
ADDRESSES: All preapplications, referencing Program Notice 98-08,
should be sent to Dr. Roland F. Hirsch, ER-73, Mail Stop F-240, Office
of Biological and Environmental Research, U.S. Department of Energy,
19901 Germantown Road, Germantown, MD 20874-1290.
Preapplications will be accepted if submitted by U. S. Postal
Service, including Express Mail, commercial mail delivery service, or
hand delivery, but will not be accepted by fax, electronic mail, or
other means.
After receiving notification from DOE concerning successful
preapplications,
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applicants may prepare and submit formal applications. Applications
must be sent to: U.S. Department of Energy, Office of Energy Research,
Grants and Contracts Division, ER-64, 19901 Germantown Road,
Germantown, MD 20874-1290, Attn: Program Notice 98-08. The above
address for formal applications must also be used when submitting
formal applications by U.S. Postal Service Express Mail, any commercial
mail delivery service, or when hand carried by the applicant.
FOR FURTHER INFORMATION CONTACT: Dr. Roland F. Hirsch, ER-73, Mail Stop
F-240, Office of Biological and Environmental Research, Office of
Energy Research, U.S. Department of Energy, 19901 Germantown Road,
Germantown, MD 20874-1290, telephone: (301) 903-5349, fax: (301) 903-
0567, E-mail: [email protected], or Mr. Mark Gilbertson, Office
of Science and Risk Policy, Office of Science and Technology, Office of
Environmental Management, 1000 Independence Avenue, SW, Washington,
D.C. 20585, telephone: (202) 586-7150, E-mail:
[email protected]. This Notice is also available on the World
Wide Web at http://www.er.doe.gov/production/grants/fr98__08.html.
SUPPLEMENTARY INFORMATION: The Office of Environmental Management, in
partnership with the Office of Energy Research, sponsors the
Environmental Management Science Program (EMSP) to fulfill DOE's
continuing commitment to the cleanup of DOE's environmental legacy. The
program was initiated in Fiscal Year 1996. We are soliciting ideas for
basic scientific research which promotes the broad national interest of
a better understanding of the fundamental characteristics of highly
radioactive chemical wastes and their effects on the environment.
The DOE Environmental Management program currently has ongoing
applied research and engineering efforts under its Technology
Development Program. These efforts must be supplemented with basic
research to address long-term technical issues crucial to the EM
mission. Basic research can also provide EM with near-term fundamental
data that may be critical to the advancement of technologies that are
under development but not yet at full scale nor implemented. Proposed
basic research under this Notice should contribute to environmental
management activities that would decrease risk for the public and
workers, provide opportunities for major cost reductions, reduce time
required to achieve EM's mission goals, and, in general, should address
problems that are considered intractable without new knowledge. This
program is designed to inspire ``breakthroughs'' in areas critical to
the EM mission through basic research and will be managed in
partnership with ER. ER's well-established procedures, as set forth in
the Energy Research Merit Review System, as published in the Federal
Register, March 11, 1991, Vol. 56, No. 47, pages 10244-10246, will be
used for merit review of applications submitted in response to this
Notice. This information is also available on the World Wide Web at
http://www.er.doe.gov/production/grants/merit.html. Subsequent to the
formal scientific merit review, applications that are judged to be
scientifically meritorious will be evaluated by DOE for relevance to
the objectives of the Environmental Management Science Program.
Additional information can be obtained at http://www.em.doe.gov/
science.
Additional Notices for the Environmental Management Science Program
may be issued during Fiscal Year 1998 covering other areas within the
scope of the EM program.
Purpose
The need to build a stronger scientific basis for the Environmental
Management effort has been established in a number of recent studies
and reports. The FY 1998 Conference Report for Appropriations for
Energy and Water Development, Report 105-271, dated September 26, 1997,
on page 92 states the following:
``The conferees are pleased with the progress to date in
implementing the environmental science program * * *''
The Environmental Management Advisory Board Science Committee
(Resolution on the Environmental Management Science Program, May 2,
1997) made the following observations:
``EMSP results are likely to be of significant value to EM'' * *
* ``Early program benefits include: improved understanding of EM
science needs, linkage with technology needs, and expansion of the
cadre of scientific personnel working on EM problems'' * * *
``Science program has the potential to lead to significant
improvement in future risk reduction and cost and time savings.''
The objectives of the Environmental Management Science Program are
to:
Provide scientific knowledge that will revolutionize
technologies and clean-up approaches to significantly reduce future
costs, schedules, and risks;
``Bridge the gap'' between broad fundamental research that
has wide-ranging applicability such as that performed in DOE's Office
of Energy Research and needs-driven applied technology development that
is conducted in EM's Office of Science and Technology; and
Focus the Nation's science infrastructure on critical DOE
environmental management problems.
Representative Research Areas
Basic research is solicited in areas of science with the potential
for addressing problems in the cleanup of high level radioactive waste.
Relevant scientific disciplines include, but are not limited to,
chemistry (including actinide chemistry, analytical chemistry and
instrumentation, interfacial chemistry, and separation science),
computer and mathematical sciences, engineering science (chemical and
process engineering), materials science (degradation mechanisms,
modeling, corrosion, non-destructive evaluation, sensing of waste
hosts, canisters), and physics (fluid flow, aqueous-ionic solid
interfacial properties underlying rheological processes).
Program Funding
Up to a total of $4,000,000 of Fiscal Year 1998 Federal funds is
expected to be available for new Environmental Management Science
Program awards resulting from this Notice. Multiple-year funding of
grant awards is anticipated, contingent upon the availability of funds.
Award sizes are expected to be on the order of $100,000-$300,000 per
year for total project costs for a typical three-year grant.
Collaborative projects involving several research groups or more than
one institution may receive larger awards if merited. The program will
be competitive and offered to investigators in universities or other
institutions of higher education, other non-profit or for-profit
organizations, non-Federal agencies or entities, or unaffiliated
individuals. DOE reserves the right to fund in whole or part any or
none of the applications received in response to this Notice. DOE is
under no obligation to pay for any costs associated with the
preparation or submission of applications. A parallel announcement with
a similar potential total amount of funds will be issued to DOE
Federally Funded Research and Development Centers (FFRDCs). All
projects will be evaluated using the same criteria, regardless of the
submitting institution.
Collaboration and Training
Applicants to the EMSP are strongly encouraged to collaborate with
researchers in other institutions, such as universities, industry, non-
profit
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organizations, federal laboratories and FFRDCs, including the DOE
National Laboratories, where appropriate, and to incorporate cost
sharing and/or consortia wherever feasible.
Applicants are also encouraged to provide training opportunities,
including student involvement, in applications submitted to the
program.
Collaborative research applications may be submitted in several
ways:
(1) When multiple private sector or academic organizations intend
to propose collaborative or joint research projects, the lead
organization may submit a single application which includes another
organization as a lower-tier participant (subaward) who will be
responsible for a smaller portion of the overall project. If approved
for funding, DOE may provide the total project funds to the lead
organization who will provide funding to the other participant via a
subcontract arrangement. The application should clearly describe the
role to be played by each organization, specify the managerial
arrangements and explain the advantages of the multi-organizational
effort.
(2) Alternatively, multiple private sector or academic
organizations who intend to propose collaborative or joint research
projects may each prepare a portion of the application, then combine
each portion into a single, integrated scientific application. A
separate Face Page and Budget Pages must be included for each
organization participating in the collaborative project. The joint
application must be submitted to DOE as one package. If approved for
funding, DOE will award a separate grant to each collaborating
organization.
(3) Private sector or academic applicants who wish to form a
collaborative project with a DOE FFRDC may not include the DOE FFRDC in
their application as a lower-tier participant (subcontract). Rather,
each collaborator may prepare a portion of the proposal, then combine
each portion into a single, integrated scientific proposal. The private
sector or academic organization must include a Face Page and Budget
Pages for its portion of the project. The FFRDC must include separate
Budget Pages for its portion of the project. The joint proposal must be
submitted to DOE as one package. If approved for funding, DOE will
award a grant to the private sector or academic organization. The FFRDC
will be funded, through existing DOE contracts, from funds specifically
designated for new FFRDC projects. DOE FFRDCs will not compete for
funding already designated for private sector or academic
organizations. Other Federal laboratories who wish to form
collaborative projects may also follow guidelines outlined in this
section.
Preapplications
A brief preapplication may be submitted. The original and five
copies must be received by January 27, 1998, to be considered. The
preapplication should identify on the cover sheet the institution,
Principal Investigator name, address, telephone, fax and E-mail
address, title of the project, and the field of scientific research
(using the list in the Application Categories section). The
preapplication should consist of up to three pages of narrative
describing the research objectives and the plan for accomplishing them,
and should also include a paragraph describing the research background
of the principal investigator and key collaborators if any.
Preapplications will be evaluated relative to the scope and
research needs of the DOE's Environmental Management Science Program by
qualified DOE program managers from both ER and EM. Preapplications are
strongly encouraged but not required prior to submission of a full
application. Please note that notification of a successful
preapplication is not an indication that an award will be made in
response to the formal application.
Application Format
Applicants are expected to use the following format in addition to
following instructions in the Office of Energy Research Application
Guide. Applications must be written in English, with all budgets in
U.S. dollars.
ER Face Page (DOE F 4650.2 (10-91))
Application classification sheet (a plain sheet of paper
with one selection from the list of scientific fields listed in the
Application Categories Section)
Table of Contents
Project Abstract (no more than one page)
Budgets for each year and a summary budget page for the
entire project period (using DOE F 4620.1)
Budget Explanation
Budgets and Budget explanation for each collaborative
subproject, if any
Project Narrative (recommended length is no more than 20
pages; multi-investigator collaborative projects may use more pages if
necessary up to a total of 40 pages):
Goals
Significance of Project to the EMSP
Background
Research Plan
Preliminary Studies (if applicable)
Research Design and Methodologies
Literature Cited
Collaborative Arrangements (if applicable)
Biographical Sketches (limit 2 pages per senior
investigator)
Description of Facilities and Resources
Current and Pending Support for each senior investigator
Application Categories
In order to properly classify each preapplication and application
for evaluation and review, the documents must indicate the applicant's
preferred scientific research field, (please use only the designation
on this list and please select only one field of scientific research)
from the following list of Field of Scientific Research:
1. Actinide Chemistry
2. Analytical Chemistry and Instrumentation
3. Interfacial Chemistry
4. Separations Science
5. Computer and Mathematical Sciences
6. Engineering Sciences
7. Materials Science
8. Physics
9. Other
Application Evaluation and Selection
Scientific Merit. The program will support the most scientifically
meritorious and relevant work, regardless of the institution. Formal
applications will be subjected to scientific merit review (peer review)
and will be evaluated against the following evaluation criteria listed
in descending order of importance as codified at 10 CFR 605.10(d):
1. Scientific and/or Technical Merit of the Project
2. Appropriateness of the Proposed Method or Approach
3. Competency of Applicant's Personnel and Adequacy of Proposed
Resources
4. Reasonableness and Appropriateness of the Proposed Budget.
External peer reviewers are selected with regard to both their
scientific expertise and the absence of conflict-of-interest issues.
Non-federal reviewers may be used, and submission of an application
constitutes agreement that this is acceptable to the investigator(s)
and the submitting institution.
Relevance to Mission. Subsequent to the formal scientific merit
review, applications which are judged to be scientifically meritorious
will be evaluated by DOE for relevance to the objectives of the
Environmental Management Science Program. These objectives were
established in the Conference Report for the Fiscal Year 1996 Energy
and Water Development Appropriations Act, and are published in the
Congressional Record--House, October 26, 1995, page H10956.
[[Page 214]]
DOE shall also consider, as part of the evaluation, program policy
factors such as an appropriate balance among the program areas,
including research already in progress. Research funded in the
Environmental Management Science Program in Fiscal Year 1996 and Fiscal
Year 1997 can be viewed at http://www.doe.gov/em52/science-grants.html.
Application Guide and Forms
Information about the development, submission of applications,
eligibility, limitations, evaluation, the selection process, and other
policies and procedures may be found in 10 CFR Part 605, and in the
Application Guide for the Office of Energy Research Financial
Assistance Program. Electronic access to the Guide and required forms
is made available via the World Wide Web at http://www.er.doe.gov/
production/grants/grants.html.
Major Environmental Management Challenges
This research announcement has been developed for Fiscal Year 1998,
along with a development process for a long-term program within
Environmental Management, with the objective of providing continuity in
scientific knowledge that will revolutionize technologies and clean-up
approaches for solving DOE's most complex environmental problems. The
following is an overview of the technical challenge facing the
Environmental Management Program in the area of High Level Radioactive
Waste which is the focus of this announcement. More detailed
descriptions of the specific technical needs and areas of emphasis
associated with this problem area can be found in the Background
section of this Notice.
High-level Radioactive Waste Tanks. The Department is the guardian
of over 300 large storage tanks containing over 90 million gallons of
highly radioactive wastes, which include organic and inorganic chemical
compounds, in solid, colloidal, slurry, and liquid phases. The
environment within the tanks is highly radioactive and chemically
harsh. A few of the tanks have leaked to the environment while others
are corroding.
Specific areas of emphasis in technology needs and research
challenges related to high level waste (HLW) tank problems include, but
are not limited to:
Characterization and Safety
Retrieval of Tank Waste and Tank Closure
Pretreatment and Separation Processes for Tank Waste
Waste Immobilization and Disposal
Historically, characterization of tank waste has been very
expensive, has failed to obtain representative data for many tanks, and
has generated safety concerns from worker exposure to radioactive
waste. Within the Characterization and Safety area there is the need to
develop systems to identify chemical and physical characteristics of
the waste in situ, improve data quality and timeliness, and reduce
safety concerns.
In the Retrieval of Tank Waste and Tank Closure area, there is the
need to develop cost-efficient methods to remove saltcake, sludge, and
waste heels and close a high-level waste tank that may contain a
flammable gas environment. Some sites have numerous tanks that contain
saltcake so that the potential cost savings of less expensive saltcake
retrieval methods is very large.
Pretreatment and Separation Processes for Tank Waste will separate
tank wastes into low-and high-level fractions, thereby significantly
reducing the volumes of high-level waste requiring disposal. These
separations include not only chemical separations, but also physical
separations.
Low level waste (LLW) immobilization will reduce waste volumes and
produce waste forms that are chemically and physically durable. EM is
applying two technologies (grout and glass) to the same waste stream to
allow an unbiased appraisal of the true costs and risks associated with
implementing each technology for full-scale tank waste remediation.
Both technologies must be robust enough to handle the range of
constituents found in the tank wastes.
The aforementioned areas of emphasis do not preclude, and DOE
strongly encourages, any innovative or creative ideas contributing to
solving EM HLW challenges mentioned throughout this Notice.
Background
Environmental Management (EM) is responsible for the development,
testing, evaluation, and deployment of remediation technologies within
a system architecture to characterize, retrieve, treat, concentrate,
and dispose of radioactive waste stored in the underground storage
tanks at DOE facilities and ultimately stabilize and close the tanks.
The goal is to provide safe and cost-effective solutions that are
acceptable to both the public and regulators.
Within the DOE complex, 335 underground storage tanks have been
used to process and store radioactive and chemical mixed waste
generated from weapon materials production and manufacturing.
Collectively, these tanks hold over 90 million gallons of high-level
and low-level radioactive liquid waste in sludge, saltcake, and as
supernate and vapor. Very little has been treated and/or disposed of in
final form.
Tanks vary in design from carbon or stainless steel to concrete,
and concrete with carbon steel liners. Two types of storage tanks are
most prevalent: the single-shell and double-shell concrete tanks with
carbon steel liners. Capacities vary from 5,000 gallons
(19m3) to 1,300,000 gallons (4920m3). The tanks
are covered with a layer of soil ranging from a few feet to tens of
feet thick.
Most of the waste is alkaline and contains a diverse portfolio of
chemical constituents including nitrate and nitrite salts
(approximately half of the total waste), hydrated metal oxides,
phosphate precipitates, and ferrocyanides. The 784 MCi of radionuclides
are distributed primarily among the transuranic (TRU) elements and
fission products, specifically strontium-90, cesium-137, and their
decay products yttrium-90 and barium-137. In-tank atmospheric
conditions vary in severity from near ambient to temperatures over
93 deg.C. Tank void-space radiation fields can be as high as 10,000
rad/h.
EM is focusing attention on four DOE locations:
Hanford Site near Richland, Washington.
Idaho National Engineering and Environmental Laboratory
near Idaho Falls, Idaho.
Oak Ridge Reservation near Oak Ridge, Tennessee.
Savannah River Site near Aiken, South Carolina.
Hanford has 177 tanks that contain approximately 55 million gallons
of hazardous and radioactive waste. There are 149 single-shell tanks
that have exceeded their life expectancy. Sixty-seven of these tanks
have known or suspected leaks. Due to several changes in the production
processes since the early 1940s, some of the tanks contain incompatible
waste components, generating hydrogen gas and excess heat that further
compromise tank integrity.
The 11 stainless steel tanks at Idaho store approximately 2 million
gallons of acidic radioactive liquids. Additionally, approximately 4000
m3 of calcined waste solids are stored in seven stainless
steel bins enclosed in massive underground concrete vaults.
Dilute low-level waste (LLW) supernatants and associated sludge at
Oak Ridge are stored in the inactive
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Gunite and associated tanks, the old hydrofracture tanks, and other
tanks. The wastes from underground collection systems are currently
being retrieved and consolidated in the stainless steel central
treatment/storage tanks, including eight Melton Valley Storage Tanks.
Tank waste at Savannah River consists of 33 million gallons of
salt, salt solution, and sludge containing waste stored in 51
underground storage tanks, two of which have been closed (emptied of
all waste and filled with grout). Twenty-three tanks are being retired,
because they do not have full secondary containment. Nine tanks have
leaked detectable quantities of waste from the primary tank to
secondary containment.
Most of the participant sites share four problem areas. These areas
are:
Characterization and Safety.
Retrieval of Tank Waste and Tank Closure.
Pretreatment and Separation Processes for Tank Waste.
Waste Immobilization and Disposal.
Characterization and Safety
DOE, contractors, and stakeholders have committed to a safe and
efficient remediation of HLW, mixed waste, and hazardous waste stored
in underground tanks across the DOE complex.
Currently, there are only limited fully developed or deployed in
situ techniques to characterize tank waste. In situ characterization
can eliminate the time delay between sample removal and sample analysis
and aid in guiding the sampling process while decreasing the cost
(approximately $1 million is spent for one tank core extrusion) of
waste analysis. Most importantly, remote analysis eliminates sample
handling and safety concerns due to worker exposure. However, analysis
of extruded tank samples allows a more complete chemical and physical
characterization of the waste when needed. Knowledge of the chemical
and radioactive composition and physical parameters of the waste is
essential to safe and effective tank remediation.
There are three primary drivers for the development of new chemical
analysis methods to support tank waste remediation: (1) provide
analyses for which there are currently no reliable existing methods,
(2) replace current methods that require too much time and/or are too
costly, and (3) provide methods that evolve into on-line process
analysis tools for use in waste processing facilities.
Characterization of the elemental and isotopic chemical
constituents in DOE tank waste is an important function in support of
DOE tank waste operation and remediation functions. Proper waste
characterization enables: safe operation of the tank farms; resolution
of tank safety questions; and development of processes and equipment
for retrieval, pretreatment, and immobilization of tank waste. All of
these operations are dependent on the chemical analysis of tank waste.
Moisture is one of the key elements influencing the safety status
of some of Hanford's HLW tanks. Ferrocyanides were added to tank wastes
to increase the available storage space when production outstripped the
ability to provide adequate storage space. Organics from some of the
extraction processes used at Hanford ended up in tanks because of
inefficient reagent recovery processes. Moisture provides a thermal
buffer for the prevention of ignition and propagation of thermal
reactions in waste containing ferrocyanides or organics. Insufficient
moisture level raises the possibility of explosion. The conditions for
a thermal event are reduced by the presence of water in the wastes. A
method is needed to measure and quantify tank waste water
concentrations in situ.
The need for chemical characterization of the tank wastes is driven
by both safety and operational considerations. Safety drivers include
the monitoring of organic chemicals and oxidizers to address
flammability and energetics, nitrate and nitrite levels to address
corrosion concerns, plutonium levels to address criticality prevention
considerations, and detection of organic and inorganic species to
identify chemical incompatibility hazards associated with
ferrocyanides, nitrates, sulfates, carbonates, phosphates, and other
oxyanions. Operational concerns include the monitoring of phosphate
levels driven by the potential formation of sodium phosphate crystals,
thereby increasing the viscosity of the waste by formation of a
gelatinous matrix which will reduce the ability of pumps to transfer
and retrieve waste.
Current techniques of tank waste analysis involve the removal of
core samples from tanks, followed by costly and time consuming wet
analytical laboratory testing. Savings in both cost and time could be
realized in techniques that involve in situ probes for direct analysis
of tank materials.
Single-shell and double-shell waste tank construction is common
across the DOE complex. The single-shell tanks present potential
environmental hazards because only a single barrier contains the
liquids and any breach in the barrier will cause contaminant spillage.
A sluicing method being considered to retrieve the waste requires
thousands of gallons of water, raising the possibility of HLW leakage
into the surrounding environment. In other tanks, water is added to
prevent the waste matrix from drying and provides a deterrent from
possible ignition due to flammable gases. There is a need to develop
instrumentation to determine the location of a leak, the amounts of
materials that were exposed, and the quantity of the contaminant
material.
Assessments of the long-term performance of waste forms is rare;
performance assessments of radionuclide containment rely primarily on
the geologic barriers (e.g., long travel times in hydrologic systems or
sorption on mineral surfaces). The physical and chemical durability of
the waste form, however, can contribute greatly to the successful
isolation of radionuclides; thus the effects of radiation on physical
properties and chemical durability of waste forms are of great
importance. The changes in chemical and physical properties occur over
relatively long periods of storage, up to a million years, and at
temperatures that range from 100 to 300 degrees Celsius, depending on
waste loading, age of the waste, depth of burial, and the repository-
specific geothermal agent. Thus, a major challenge is to effectively
simulate high-dose radiation effects that will occur over relatively
low-dose rates over long periods of time at elevated temperatures. Thus
there is a paramount need for improved understanding and modeling of
the degradation mechanisms and behavior of primary radioactive waste
hosts and/or their containment canisters, corrosion mechanisms and
prevention in aqueous and/or alkali halide containing environments, and
remote sensing and non-destructive evaluation.
Examples of specific science research challenges include but are
not limited to: basic measurement science and sensor development
required for remote detection of low concentrations of hydrogen inside
tanks and in containers; basic analytical studies needed to develop new
methods for chemical and physical characterization of solid and liquids
in slurries and for development of advanced processing methodologies;
basic instrument development needed to perform in situ radiological
measurements and collect spatially resolved species and concentration
data; basic materials and engineering science needed to develop
radiation hardened instrumentation.
Retrieval of Tank Waste and Tank Closure
Underground tanks throughout the DOE in Hanford, Savannah River,
Oak
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Ridge, and Idaho have stored a diverse accumulation of wastes during
the past fifty years of weapons and fuel production. If these tanks
were entrapped in a manner that would preclude the escape into the
environment for hundreds of years, there would be no reason to disturb
them. However, a number of the storage tanks are approaching the end of
their design life. At the four sites, 90 tanks have either leaked or
are assumed to have leaked waste into the soil and sediments near the
tanks.
Recently, dewatering processes have removed much of the free liquid
from the alkaline waste tanks. The tanks now contain wastes ranging in
consistency from remaining supernate and soft sludge to concrete-like
saltcake. Tanks also contain miscellaneous foreign objects such as
Portland cement, measuring tapes, samarium balls, and in-tank hardware
such as cooling coils and piping. Unlimited sluicing, adding large
quantities of water to suspend solids, is the baseline method for
sludge removal from tanks. This process is not capable of retrieving
all of the material from tanks. Besides dealing with aging tanks and
difficult wastes, retrieval also faces the problem of the tank design
itself. Retrieval tools must be able to enter the tanks, which are
under an average of 10 feet of soil, through small openings called
risers in the tops of the tanks.
Retrieval of tank waste and tank closure requires tooling and
process alternative enhancements to mixing and mobilizing bulk waste as
well as dislodging and conveying heels. Heel removal is linked to tank
closure. The working tools and removal devices being developed include
suction devices, rubblizing devices, water and air jets, waste
conditioning devices, grit blasting devices, transport and conveyance
devices, cutting and extraction tools, monitoring devices, and various
mechanical devices for recovery or repair of waste dislodging and
conveyance tools.
The areas directly below the access risers are often disturbed or
contain a significant amount of discarded debris. Therefore, evaluation
of tank waste characteristics by measurements taken at these locations
may not be representative of the properties of the waste in other areas
of the tanks.
To monitor current conditions and plan for tank remediation, more
information on the tank conditions and their contents is required.
Current methods used at DOE tank sites are limited to positioning
sensors, instruments, and devices to locations directly below access
penetrations or attached to a robotic arm for off-riser positioning.
These systems can only deploy one type of sensor, requiring multiple
systems to perform more than one function in the tank.
Currently, decisions regarding necessary retrieval technologies,
retrieval efficiencies, retrieval durations, and costs are highly
uncertain. Although tank closure has been completed on only two HLW
tanks (at Savannah River), the tank contents proved amenable to waste
retrieval using current technology. DOE has just begun to address the
issue of how clean a tank must become before it is closed. Continued
demonstration that tank closure criteria can be developed and
implemented will provide substantial benefit to DOE.
A related problem that retrieval process development is examining,
is the current lack of a retrieval decision support tool for the end
users. As development activities move forward toward collection of
retrieval performance and cost data, it has become very evident that
the various sites across the complex need to have a decision tool to
assist end users with respect to waste retrieval and tank closure. Tank
closure is intimately tied to retrieval, and the sensitivity of closure
criteria to waste retrieval is expected to be very large.
All the existing processes and technologies that could be used as a
baseline for tank remediation have not yet been identified. Identifying
these processes is one of EM's major issues in addressing the tank
problems. The overall purpose of retrieval enhancements is to continue
to lead the efforts in the basic understanding and development of
retrieval processes in which waste is mobilized sufficiently to be
transferred out of tanks in a cost-effective and safe manner. From that
basic understanding, data are provided to end users to assist them in
the retrieval decisionmaking process. The overall purpose of retrieval
enhancements is to identify processes that can be used to reduce cost,
improve efficiency, and reduce programmatic risk.
The hermetic sealing and closure of containment vessels and the
long term resistance to corrosion and stress corrosion cracking and
failure of such seals and closures warrants attention. Routine or
conventional welding and joining procedures, while adequate to form
hermetic seals in a non-hostile environment, may result in local
composition gradients across weld or join interfaces and heat-affected-
zones that create local electrochemical cells that are vulnerable to
galvanic degradation and/or corrosion related cracking. Research is
needed to establish reliable welding or joining procedures that will
not result in either the establishment of local gradients in chemical
composition or in grain-boundary depletion of passivating chemical
elements at welding or joining closures.
Basic engineering and separation science studies are needed to
support tank remediation of liquids which contain high concentrations
of solids.
Pretreatment and Separation Processes for Tank Waste
DOE has about 90 million gallons of HLW and LLW stored in tanks at
four primary sites within the DOE complex. It is neither cost-effective
nor practical to treat and dispose of all of the tank waste to meet the
requirements of the HLW repository program and the Nuclear Waste Policy
Act.
The current baseline technology systems for waste pretreatment at
DOE's tank waste sites are expensive. Technology gaps exist. Large
volumes of HLW will be generated, while there is limited space in the
planned Nuclear Waste Repository for HLW from DOE. Even if adequate
space were made available, treatment and disposal of HLW is still very
expensive, estimated to be about $1 million for each canister of
vitrified HLW.
Only a small fraction of the waste, by weight, is made up of
radionuclides. The bulk of the waste is chemical constituents
intermingled with, and sometimes chemically bonded to, the
radionuclides. However, the chemicals and radionuclides can be
separated into HLW and LLW fractions for easier treatment and disposal.
Most of the waste stored in tanks was put there as a result of
nuclear fuel processing for weapons production. In that process,
irradiated fuel and its cladding were first dissolved, uranium and
plutonium were recovered as products, and the highly radioactive
fission product wastes were concentrated and sent to tanks for long-
term storage.
Fuel processing at Savannah River did not change substantially from
the beginning of operations in about 1955 to the present. While these
wastes are fairly uniform, they still require pretreatment to separate
the LLW from HLW prior to immobilization. Waste at Idaho is stored at
acidic pH in stainless steel tanks. Much of it has already been
calcined at high temperature to a dry powder. Tank wastes at Oak Ridge
are small in volume (less than 1 million gallons) and radionuclide
inventory (0.16 MCi) compared to other sites (33
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million gallons and 534 MCi at Savannah River and 55 million gallons
and 198 MCi at Hanford).
At Hanford, several processes were used over the years (beginning
in 1944), each with a different chemical process. This resulted in
different waste volumes and compositions. Wastes at Hanford and
Savannah River are stored as highly alkaline material so as not to
corrode the carbon steel tanks. The process of converting the waste
from acid to alkaline resulted in the formation of different physical
forms within the waste.
The primary forms of waste in tanks are sludge, saltcake, and
liquid. The bulk of the radioactivity is known to be in the sludge
which makes it the largest source of HLW. Saltcake is characteristic of
the liquid waste with most of the water removed. Saltcake is found
primarily in older single-shell tanks at Hanford.
Saltcake and liquid waste contain mostly sodium nitrate and sodium
hydroxide salts. They also contain soluble radionuclides such as
cesium. Strontium, technetium, and transuranics are also present in
varying concentrations. The radionuclides must be removed, leaving a
large portion of waste to be treated and disposed of as LLW and a very
small portion that is combined with HLW from sludge for subsequent
treatment and disposition.
Waste in tanks has been blended and evaporated to conserve space.
Although sludge contains most of the radionuclides, the amount of HLW
glass produced (vitrification is the preferred treatment of HLW) could
be very high without pretreatment of the sludge. Pretreatment of the
sludge by washing with alkaline solution can remove certain
nonradioactive constituents and reduce the volume of HLW. Pretreatment
can also remove constituents that could degrade the stability of HLW
glass. If the alkaline sludge washing is not effective, some sludge may
need to be dissolved in acid and treated by extraction techniques to
make a suitable feed to HLW vitrification. This option is currently
outside the sites baseline.
The pretreatment functional area seeks to address multiple needs
across the DOE complex. The primary objectives are to reduce the volume
of HLW, reduce hazards associated with treating LLW, and minimize the
generation of secondary waste.
The concentration of certain chemical constituents such as
phosphorus, sulfur, and chromium in sludge can greatly increase the
volume of HLW glass produced upon vitrification of the sludge. These
components have limited solubility in the molten glass at very low
concentrations. Some sludge has high concentrations of aluminum
compounds which can also be a controlling factor in determining the
volume of HLW glass produced. Aluminum above a threshold concentration
in the glass must be balanced with proportional amounts of other glass-
forming constituents such as silica. There are estimated to be 25
different types of sludge at Hanford distributed among more than 100
tanks. Samples from 49 tanks would represent approximately 93 percent
sludge in Hanford tanks. Testing of enhanced sludge washing, the
combination of caustic leaching and water washing of sludge, on all of
these samples is needed to determine whether enhanced sludge washing
will result in an acceptable volume of HLW glass destined for the
repository and will allow processing in existing carbon steel tanks at
Hanford and Savannah River.
The efficiency of enhanced sludge washing is not completely
understood. Inadequate removal of key sludge components could result in
production of an unacceptably large volume of HLW glass. Improvements
are needed to increase the separation of key sludge constituents from
the HLW.
Enhanced sludge washing is planned to be performed batchwise in
large double-shell tanks of nominal one million gallon capacity. This
will generate substantial volumes of waste solutions which require
treatment and disposal as LLW. Settling times for suspended solids may
be excessive and the possibility of colloid or gel formation could
prohibit large-scale processing. Alternatives are needed that will
reduce the amount of chemical addition required and prevent the
possibility of colloid formation. Sludge at Savannah River, Hanford,
and Oak Ridge will be washed to remove soluble components prior to HLW
vitrification. Removing suspended solids from the wash solutions is
inherently inefficient due to long intervals required for the solids to
settle out. The baseline process for sludge washing at Savannah River
and Hanford is done batchwise in large, one-million gallon underground
storage tanks. This requires large volumes of wash solution, powerful
mixing pumps, and long settling times. Retrieval of waste using large
volumes of dilution water is planned at Hanford. To consider the
benefits of flocculent addition and the possibility of using
countercurrent decantation to help optimize sludge washing, the
settling characteristics of the solids need to be determined.
Baseline sludge washing processes at both Hanford and Savannah
River call for large volumes of caustic (sodium hydroxide) solution.
The supernatant from sludge washing then becomes feed to LLW treatment.
The added caustic can be recovered after washing and recycled to
subsequent sludge washing steps. In addition, the HLW sludge at Hanford
and Savannah River contains large quantities of sodium salts that can,
in principle, be recovered as sodium hydroxide and also be recycled.
Approximately 1.8 million gallons of acidic liquid waste are stored
in single-shell, stainless steel, underground storage tanks at Idaho.
In 1992 a Notice of Noncompliance was filed stating that the tanks did
not meet secondary containment requirements of the Resource
Conservation and Recovery Act. Subsequently, an agreement was reached
between DOE, the Environmental Protection Agency, and the Idaho
Department of Health and Welfare that commits DOE to remove the liquid
waste from all underground tanks by the year 2015. Recent discussions
with the state of Idaho have accelerated this date to 2012.
The baseline treatment for Idaho liquid wastes produced after 2012
is the full treatment option, wherein actinides and fission products
will be removed from the liquid waste and HLW calcine.
The depleted stream will be processed to Class A LLW standards and
the radionuclides will be immobilized in an HLW fraction.
The transuranic extraction process for removal of actinides, or
transuranics, from acidic wastes has been tested on actual Idaho waste
in continuous countercurrent process equipment. The strontium
extraction process shows promise for co-extraction of strontium and
technetium and also has been demonstrated on Idaho waste in continuous
countercurrent operation.
DOE's underground storage tanks contain liquid wastes with high
concentrations of radioactive cesium. The various processes for
retrieving and redissolution of HLW calcine for pretreatment are not
fully demonstrated.
DOE's underground storage tanks at Hanford, Savannah River, Oak
Ridge, and Idaho contain liquid wastes with high concentrations of
radioactive cesium. Cesium is the primary radioactive constituent found
in alkaline supernatant wastes. Since the primary chemical components
of alkaline supernatants are sodium nitrate and sodium hydroxide, the
majority of the waste could be disposed of as LLW if the radioactivity
could be reduced below Nuclear Regulatory Commission limits. Processes
have been
[[Page 218]]
demonstrated that removed cesium from alkaline supernatants and
concentrate it for eventual treatment and disposal as HLW.
At Hanford, cesium must be removed to a very low level (3 Ci/m3) to
allow supernatant waste to be treated as LLW and disposed of in a near-
surface disposal facility. The revised Hanford Federal Facility
Agreement and Consent Order, or Tri-Party Agreement (between DOE,
Environmental Protection Agency and the Washington State Department of
Ecology) also recommends treatment of LLW in a contact-maintained or
minimally shielded vitrification facility to speed remediation and
reduce costs. Cesium removal performance data are needed to estimate
dose rates for this process and provide input to the design of an LLW
pretreatment facility for Hanford supernatants.
At Savannah River, cesium removal by ion exchange may be needed as
an alternative to the current in-tank precipitation process. Cesium ion
exchange may also be needed to separate cesium from Defense Waste
Processing Facility recycle, or offgas condensate, to greatly reduce
the amount of cesium that is routed back to the waste storage tanks.
Technetium (Tc)-99 has a long half-life (210,000 years) and is very
mobile in the environment when in the form of the pertechnetate ion.
Removal of Tc from alkaline supernatants and sludge washing liquids is
expected to be required at Hanford to permit treatment and disposal of
these wastes as LLW. The disposal requirements are being determined by
the long-term performance assessment of the LLW waste form in the
disposal site environment. It is also expected that Tc removal will be
required for at least some wastes to meet Nuclear Regulatory Commission
LLW criteria for radioactive content. To meet these expected
requirements, there is a need to develop technology that will separate
this extremely long-lived radionuclide from the LLW stream and
concentrate it for feed to HLW vitrification.
A number of liquid streams encountered in tank waste pretreatment
contain fine particulate suspended solids. These streams may include
tank waste supernatant, waste retrieval sluicing water, and sludge wash
solutions. Other process streams with potential for suspended solids
include evaporator products and ion exchange feed and product streams.
Suspended solids will foul process equipment such as ion exchangers.
Radioactive solids will carry over into liquid streams destined for LLW
treatment, increasing waste volume for disposal and increasing the need
for shielding of process equipment. Streams with solid/liquid
separation needs exist at all of the DOE tank waste sites.
Some examples of specific science research challenges include but
are not limited to: fundamental analytical chemical studies needed for
improvement of separation processes; materials science of waste forms
germane to their performance; elucidation of technetium chemistry;
basic engineering and separation science studies required to support
pretreatment activities and the development of solid/liquid
separations; fundamental separations chemistry of precipitating agent
and ion exchange media needed to support the development of improved
methods for decontamination of HLW; fundamental physical chemistry
studies of sodium nitrate/nitrite needed for HLW processing; basic
materials science studies concerned with the dissolution of mixed oxide
materials characteristic of calcine waste needed to design improved
pretreatment processes; basic chemistry of sodium when mixed with rare
earth oxides needed for the development of alternative HLW forms;
fundamental chemical studies associated with high temperature
(500 deg.C) calcination of nitrate solutions using agents others than
sugar needed for advanced HLW calcination processing.
Waste Immobilization and Disposal
Waste immobilization technology converts radioactive waste into
solid waste forms which will last in natural environments for thousands
of years. Wastes requiring immobilization at DOE sites include LLW such
as the pretreated liquid waste from waste tanks and HLW such as the
tank sludge. There are also a number of secondary wastes requiring
immobilization that result from tank waste remediation operations, such
as resins from cesium and technetium removal operations.
The baseline technologies to immobilize radioactive wastes from
underground storage tanks at DOE sites include converting LLW to either
grout or glass and converting HLW to borosilicate glass. Grout is a
cement-based waste form that is produced in a mixer tank and then
poured into canisters or pumped into vaults. Glass waste forms are
created in a ceramic-lined metal furnace called a melter. Tank waste
and dry materials used to form glass are mixed and heated in the melter
to temperatures ranging from 1,800 deg.F to 2,700 deg.F. The molten
mixture is then poured into log-shaped canisters for storage and
disposal. The working assumption is that the LLW will be disposed of on
site, or at the Waste Isolation Pilot Plant if transuranic elements are
present. The HLW will be shipped for off-site disposal in a licensed
HLW repository, such as the one proposed at Yucca Mountain, Nevada.
Methods are needed to immobilize the LLW fraction resulting from
the separation of radionuclides from the liquid and high-level calcine
wastes at Idaho. LLW is to be mixed with grout, poured into steel
drums, and transferred to an interim storage facility, but alternatives
are being considered. Tests must be conducted with surrogate and actual
wastes to support selection of a final waste form. Savannah River has
selected saltstone grout (pumped to above ground concrete vaults and
solidified) as the final waste form. Savannah River would like to
evaluate LLW glass as an alternative to saltstone disposal.
DOE sites at Hanford, Savannah River, Idaho and Oak Ridge will
remove cesium from the hazardous radioactive liquid waste in the
underground storage tanks. If cesium is removed, it costs less to treat
the rest of the waste. However, cesium removal from tank waste, while
cost-effective, creates a significant volume of solid waste that must
be turned into a final waste form for ultimate disposal. The plan is to
separate cesium from the liquid waste using ion exchange or other
separations media, treat the cesium-loaded separations media to prepare
it for vitrification, and convert the cesium product into a glass waste
form suitable for final disposal. Personnel exposures during processing
and the amount of hazardous species in the offgases must be kept within
safe limits at all times.
The effectiveness of advanced oxidation technology for treating
organic cesium-loaded separations media prior to vitrification is not
proven. After a suitable melter feed is obtained, vitrification of the
cesium-loaded media must be demonstrated. Technology development is
needed because: (1) Compounds are in the separation media that must be
destroyed or they will cause flammability problems in the melter and
decrease the durability and waste loading of the final waste form, (2)
high beta/gamma dose rates are associated with handling cesium-
containing waste, and (3) cesium volatizes in the melter and becomes a
highly radioactive offgas problem.
Confidence and assurance that long-term immobilization will be
successful in borosilicate glass warrants research and improved
understanding of the
[[Page 219]]
structural and thermodynamic properties of glass (including the
structure and energetics of stable and metastable phases), systematic
irradiation studies that will simulate long-term self-irradiation doses
and spectra (including archived glasses containing Pu or Cm, and over
the widest range of dose, dose rate and temperature) and predictive
theory and modeling based on computer simulations (including ab initio,
Monte Carlo, and other methods).
Some examples of specific science research challenges include but
are not limited to: fundamental chemical studies needed to determine
species concentrations above molten glass solutions containing heavy
metals, cesium, strontium, lanthanides, actinides, with and without a
cold cap composed of unmelted material; materials science studies of
molten materials that simulate conditions anticipated during
vitrification and storage in vitrified form of HLW needed to develop
improved processes and formulations; fundamental physical chemistry
studies of sodium nitrate/nitrite mixtures needed for HLW
stabilization.
References for Background Information
Note: World Wide Web locations of these documents are provided
where possible. For those without access to the World Wide Web, hard
copies of these references may be obtained by writing Mark A.
Gilbertson at the address listed in the FOR FURTHER INFORMATION
CONTACT section.
DOE. 1997. Accelerating Cleanup: Focus on 2006, Discussion Draft.
http://www.em.doe.gov/acc2006
DOE. 1997. Radioactive Tank Waste Remediation Focus Area Technology
Summary (Rainbow Book). http://www.em-52.em.doe.gov/ifd/rbbooks/tanks/
tansrb.htm
DOE. 1997. Research Needs Collected for the EM Science Program--
June 1997. http://www.doe.gov/em52/needs.html
DOE. 1997. U.S. Department of Energy Strategic Plan. http://
www.doe.gov/policy/doeplan.htm
DOE. 1996. Estimating the Cold War Mortgage: The 1996 Baseline
Environmental Management Report. March 1996. U.S. Department of Energy
Office of Environmental Management, Washington, D.C. http://
www.em.doe.gov/bemr96/index.html
DOE. 1996. Office of Environmental Restoration EM-40. http://
www.em.doe.gov/er/index.html
DOE. 1996. Office of Nuclear Material and Facility Stabilization
EM-60. http://www.em.doe.gov/menu/?nucmat.html
DOE. 1996. Office of Science and Risk Policy EM-52 and
Environmental Management Science Program. http://www.em.doe.gov/
science/
DOE. 1996. Office of Science and Technology EM-50. http://em-
50.em.doe.gov/
DOE. 1996. Office of Waste Management EM-30. http://www.em.doe.gov/
menu/?wstmgmt.html
DOE. 1996. Spent Nuclear Fuel. DOE-Owned SNF Technology Integration
Plan. U.S. Department of Energy, Washington, DC. DOE/SNF-PP-002, May
1996. http://tikal.inel.gov/tip__int.htm
DOE. 1996. Taking Stock: A Look at the Opportunities and Challenges
Posed by Inventories from the Cold War Era. The U.S. Department of
Energy, Office of Environmental Management, Washington, DC. http://
www.em.doe.gov/takstock/index.html
DOE. 1995. Closing the Circle on the Splitting of the Atom: The
Environmental Legacy of Nuclear Weapons Production in the United States
and What the Department of Energy is Doing About It. The U.S.
Department of Energy, Office of Environmental Management, Office of
Strategic Planning and Analysis, Washington, D.C. http://
www.em.doe.gov/circle/index.html
``Radiation Effects in Glasses Used for Immobilization of High-
Level Waste and Plutonium Disposition'', W. J. Weber, R.C. Ewing, C. A.
Angell, G. W. Arnold, A. N. Cormack, J.M. Delaye, D. L. Griscom, L. W.
Hobbs, A. Navrotsky, D. L. Price, A. M. Stoneham, and M. C. Weinberg,
J. Mater. Res., Vol. 12, No. 8, August 1997, pp. 1946-1978.
National Research Council. 1997. Building an Environmental
Management Science Program: Final Assessment. National Academy Press,
Washington, DC. http://www.nap.edu/readingroom/books/envmanage/
National Research Council. 1995. Improving the Environment: An
Evaluation of DOE's Environmental Management Program. National Academy
Press, Washington, D.C. http://www.nap.edu/readingroom/books/doeemp/
Secretary of Energy Advisory Board. Alternative Futures for the
Department of Energy National Laboratories. February 1995. Task Force
on Alternative Futures for the Department of Energy National
Laboratories, Washington, D.C. http://www.doe.gov/html/doe/whatsnew/
galvin/tf-rpt.html
U.S. Congress, Office of Technology Assessment. Complex Cleanup:
The Environmental Legacy of Nuclear Weapons Production, February 1991.
U.S. Government Printing Office, Washington, D.C. NTIS Order number:
PB91143743. To order, call the NTIS sales desk at (703) 487-4650.
http://www.wws.princeton.edu:80ota/disk1/1991/9113__n.html
National Science and Technology Council. 1996. Assessing
Fundamental Science, Council on Fundamental Science. http://
www.nsf.gov/sbe/srs/ostp/assess/
The Catalog of Federal Domestic Assistance Number for this
program is 81.049, and the solicitation control number is ERFAP 10
CFR Part 605.
Issued in Washington, DC, December 24, 1997.
Ralph H. DeLorenzo,
Acting Associate Director for Resource Management, Office of Energy
Research.
[FR Doc. 98-114 Filed 1-2-98; 8:45 am]
BILLING CODE 6450-01-P