[Federal Register Volume 77, Number 54 (Tuesday, March 20, 2012)]
[Proposed Rules]
[Pages 16175-16183]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-6665]
========================================================================
Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
========================================================================
Federal Register / Vol. 77, No. 54 / Tuesday, March 20, 2012 /
Proposed Rules
[[Page 16175]]
NUCLEAR REGULATORY COMMISSION
10 CFR Part 50
[NRC-2011-0299]
RIN 3150-AJ08
Station Blackout
AGENCY: Nuclear Regulatory Commission.
ACTION: Advance notice of proposed rulemaking.
-----------------------------------------------------------------------
SUMMARY: The U.S. Nuclear Regulatory Commission (NRC or the Commission)
is issuing this Advance Notice of Proposed Rulemaking (ANPR) to begin
the process of considering amendments of its regulations that address a
condition known as station blackout (SBO). SBO involves the loss of all
onsite and offsite alternating current (ac) power at a nuclear power
plant. The NRC seeks public comment on specific questions and issues
with respect to possible revisions to the NRC's requirements for
addressing SBO conditions to develop new SBO requirements and a
supporting regulatory basis. This regulatory action is one of the near-
term actions based on lessons-learned stemming from the March 2011
Fukushima Dai-ichi accident in Japan.
DATES: Submit comments by May 4, 2012. Comments received after the
comment period deadline will be considered if it is practical to do so,
but the NRC is only able to ensure consideration of comments received
on or before the end of the public comment period. Due to priority of
this regulatory action and the associated effort on the part of the
Commission to expedite the action, the Commission will not accept
requests for extensions of the public comment period unless
extraordinary circumstances exist.
ADDRESSES: Please include Docket ID NRC-2011-0299 in the subject line
of your comments. For additional instructions on submitting comments
and instructions on accessing documents related to this action, see
``Submitting Comments and Accessing Information'' in the SUPPLEMENTARY
INFORMATION section of this document. You may submit comments by any
one of the following methods:
Federal Rulemaking Web Site: Go to http://www.regulations.gov and search for documents filed under Docket ID NRC-
2011-0299. Address questions about NRC dockets to Carol Gallagher;
telephone: 301-492-3668; email: [email protected].
Mail comments to: Secretary, U.S. Nuclear Regulatory
Commission, Washington, DC 20555-0001, ATTN: Rulemakings and
Adjudications Staff.
Email comments to: [email protected]. If you do
not receive a reply email confirming that we have received your
comments, contact us directly at 301-415-1677.
Hand deliver comments to: 11555 Rockville Pike, Rockville,
Maryland 20852, between 7:30 a.m. and 4:15 p.m. Federal workdays.
(Telephone: 301-415-1677.)
Fax comments to: Secretary, U.S. Nuclear Regulatory
Commission at 301-415-1101.
FOR FURTHER INFORMATION CONTACT: Timothy A. Reed, Office of Nuclear
Reactor Regulation, U. S. Nuclear Regulatory Commission, Washington, DC
20555-0001; telephone: 301-415-1462, or email: [email protected].
SUPPLEMENTARY INFORMATION:
I. Submitting Comments and Accessing Information
II. Fukushima Dai-ichi Event and the NRC Regulatory Response
III. Background
A. General Design Criteria 2 and 17
B. Station Blackout Rule
C. Petition for Rulemaking on Station Blackout Due to Coronal
Mass Ejection
D. Mitigating Strategies
IV. Discussion and Request for Public Comment
A. Advance Notice of Proposed Rulemaking Purpose
B. Rulemaking Scope
C. Rulemaking Objectives/Success Criteria
D. Functional Considerations and Requirements for Supporting
Structures, Systems, and Components and Procedures
E. Applicability to NRC Licenses and Approvals
F. Relationship Between Existing Station Blackout Requirements
in Title 10 of the Code of Federal Regulations Section 50.63 and the
New Station Blackout Requirements
G. Advisory Committee on Reactor Safeguards Recommendations
V. Public Meeting
VI. Rulemaking Process
VII. Availability of Supporting Documents
I. Submitting Comments and Accessing Information
Comments submitted in writing or in electronic form will be posted
on the NRC Web site and on the Federal rulemaking Web site, http://www.regulations.gov. Because your comments will not be edited to remove
any identifying or contact information, the NRC cautions you against
including any information in your submission that you do not want to be
publicly disclosed.
The NRC requests that any party soliciting or aggregating comments
received from other persons for submission to the NRC inform those
persons that the NRC will not edit their comments to remove any
identifying or contact information, and therefore, they should not
include any information in their comments that they do not want
publicly disclosed.
You can access publicly available documents related to this
document using the following methods:
NRC's Public Document Room (PDR): The public may examine
and have copied for a fee, publicly available documents at the NRC's
PDR, Room O-1F21, One White Flint North, 11555 Rockville Pike,
Rockville, Maryland 20852.
NRC's Agencywide Documents Access and Management System
(ADAMS): Publicly available documents created or received at the NRC
are available online in the NRC Library at http://www.nrc.gov/reading-rm/adams.html. From this page, the public can gain entry into ADAMS,
which provides text and image files of NRC's public documents. If you
do not have access to ADAMS or if there are problems in accessing the
documents located in ADAMS, contact the NRC's PDR reference staff at 1-
800-397-4209, or 301-415-4737, or by email to [email protected].
Federal Rulemaking Web Site: Public comments and
supporting materials related to this advance notice of proposed
rulemaking can be found at http://www.regulations.gov by searching on
Docket ID NRC-2011-0299.
[[Page 16176]]
II. Fukushima Dai-ichi Event and the NRC Regulatory Response
On March 11, 2011, a magnitude 9.0 earthquake struck off the coast
of the Japanese island of Honshu. The earthquake resulted in a large
tsunami that is estimated to have exceeded 14 meters (45 feet) in
height, which inundated the Fukushima Dai-ichi Nuclear Power Plant
site. The earthquake and tsunami produced widespread devastation across
northeastern Japan, and significantly affected the infrastructure and
industry in the northeastern coastal areas of Japan.
When the earthquake occurred, Fukushima Dai-ichi Units 1, 2, and 3
were in operation, and Units 4, 5, and 6, were shut down for routine
refueling and maintenance activities. The Unit 4 reactor fuel had been
offloaded into the Unit 4 spent fuel pool (SFP) to facilitate
maintenance activities in the reactor pressure vessel. Following the
earthquake, the three operating units automatically shut down and
offsite power was lost to the entire facility. The emergency diesel
generators started at all six units, providing ac electrical power to
critical systems at each unit. The facility response to the earthquake
appears to have been normal.
Approximately 40 minutes following the earthquake and shutdown of
the operating units, the first large tsunami wave inundated the site,
followed by additional waves. The tsunami caused extensive damage to
site facilities and resulted in a complete loss of all ac electrical
power at Units 1 through 5, a condition known as SBO. In addition, all
direct current (dc) electrical power was lost early in the event on
Units 1 and 2, and after some period of time at the other units. Unit 6
retained the function of one air-cooled emergency diesel generator.
Despite their actions, the operators lost the ability to cool the fuel
in the Unit 1 reactor after several hours, in the Unit 2 reactor after
about 70 hours, and in the Unit 3 reactor after about 36 hours,
resulting in damage to the nuclear fuel shortly after the loss of
cooling capabilities.
In the days following the Fukushima Dai-ichi nuclear accident in
Japan, the NRC Chairman directed the staff to establish a senior-level
agency task force to conduct a methodical and systematic review of the
NRC's processes and regulations to determine whether the agency should
make additional improvements to its regulatory system and to make
recommendations to the Commission for its policy direction. This
direction was provided in a tasking memorandum dated March 23, 2011,
from the NRC Chairman to the NRC Executive Director for Operations
(COMGBJ-11-0002). In SECY-11-0093, ``The Near-Term Report and
Recommendations for Agency Actions Following the Events in Japan,''
dated July 12, 2011, the Near-Term Task Force (NTTF) provided its
recommendations to the Commission regarding SBO and the need for
revising the NRC's SBO rule (Title 10 of the Code of Federal
Regulations (10 CFR) section 50.63). The staff requirements memorandum
(SRM) for SECY-11-0093, dated August 19, 2011, directed the staff to
``identify and make recommendations regarding any NTTF recommendations
that can, and in the staff's judgment, should be implemented, in part
or in whole, without unnecessary delay.''
The NTTF provided a specific proposal for SBO mitigation that was
subsequently endorsed by the National Resources Defense Council in a
petition for rulemaking (PRM), PRM-50-101 (76 FR 58165) as a way to
address SBO mitigation. The approach for SBO mitigation put forth by
the NTTF as NTTF Recommendation 4.1 was:
Initiate rulemaking to revise 10 CFR 50.63 to require each
operating and new reactor licensee to: (1) Establish a minimum
coping time of 8 hours for a loss of all ac power, (2) establish the
equipment, procedures, and training necessary to implement an
``extended loss of all ac'' coping time of 72 hours for core and
spent fuel pool cooling and for reactor coolant system and primary
containment integrity as needed, and (3) preplan and prestage
offsite resources to support uninterrupted core and spent fuel pool
cooling, and reactor coolant system and containment integrity as
needed, including the ability to deliver the equipment to the site
in the time period allowed for extended coping, under conditions
involving significant degradation of offsite transportation
infrastructure associated with significant natural disasters.
In SECY-11-0124 and SECY-11-0137, the staff provided for Commission
consideration its recommendations on those NTTF action items that
should be initiated, in part or in whole, without unnecessary delay,
and the associated prioritization for each item. Regarding SBO
mitigation actions the staff recommended that the NRC, as a near-term
action:
Engage stakeholders in support of rulemaking activities to
enhance the capability to maintain safety through a prolonged SBO.
These activities will include the development of the regulatory
basis, a proposed rule, and implementing guidance.
In SRM-SECY-11-0124, dated October 18, 2011, the Commission
approved the staff's proposed actions to implement without unnecessary
delay the NTTF recommendations as described in SECY-11-0124.
Subsequently, in SRM-SECY-11-0137, dated December 15, 2011, the
Commission approved the staff's proposed prioritization of the NTTF
recommendations and supported action on the recommendations subject to
the direction in the SRM.
Regarding regulatory actions to address SBO, the Commission
directed the staff to initiate a rulemaking on NTTF Recommendation 4.1
in the form of an ANPR. This document is responsive to that Commission
direction.
In November 2011, the Institute of Nuclear Power Operations (INPO)
issued INPO-11-005, ``Special Report on the Nuclear Accident at the
Fukushima Dai-ichi Nuclear Power Station.'' In SRM-SECY-11-0137, the
Commission directed the staff to use INPO-11-005 as an input to its
development of technical bases for any proposed regulatory changes.
Much of the technical information regarding the Fukushima Dai-ichi
accident discussed in this document has been derived from INPO-11-005.
III. Background
A. General Design Criteria 2 and 17
As defined in 10 CFR 50.2, ``design bases'' means that information
which identifies the specific functions to be performed by a facility
structure, system, or component (SSC), and the specific values or
ranges of values chosen for controlling parameters as reference bounds
for design. The actual detailed design of facility SSCs must reflect
the assigned design basis functions and assure performance of those
functions within the reference bounds for design. An applicant for a
construction permit or combined license for a facility is required,
pursuant to 10 CFR 50.34(a)(3) or 52.79(a)(4)(i), respectively, to
describe the principal design criteria (PDC) for the proposed facility.
The PDC generally identify facility SSCs and their functions, which is
part of the design bases described above. U.S. facilities for which
construction permits were issued before 1971 had plant-specific PDC,
since the Atomic Energy Commission (AEC), the authority that was the
predecessor to the NRC, had yet to develop generic requirements for
facility design criteria at that time.
On July 11, 1967, the AEC published for comment a proposed
amendment to 10 CFR part 50 entitled ``General Design Criteria for
Nuclear Power Plant Construction Permits'' (32 FR 10213). Subsequently,
on February 20, 1971, the AEC published the final general design
[[Page 16177]]
criteria (GDC) and added appendix A, ``General Design Criteria for
Nuclear Power Plants,'' to 10 CFR part 50 (36 FR 3255). The GDC provide
minimum requirements for facility PDC, and form part of the facility
design basis since they identify SSCs and their required functions at a
high level. NRC regulations, including the GDC and plant-specific PDC,
set general minimum standards for the values or ranges of values chosen
for controlling parameters as reference bounds for design, which is the
second element of the design bases defined in 10 CFR 50.2. These values
or ranges of values are determined in accordance with detailed NRC
guidance applicable to the particular SSCs found in nuclear power
facilities. The GDC relevant to this ANPR are GDC 2, which governs
consideration of natural phenomena, and GDC 17, which governs
electrical system design. For facilities with construction permits
issued before 1971, plant-specific PDC, which differ in certain
respects from GDC 2 and 17, are also relevant to this ANPR.
GDC 2
General Design Criterion 2 currently requires nuclear power plants
designed in accordance with appendix A to 10 CFR part 50 to be
protected against natural phenomena. Specifically, SSCs important to
safety shall be designed to withstand the effects of natural phenomena
such as earthquakes, tornadoes, hurricanes, floods, tsunami, and
seiches without loss of capability to perform their safety functions.
The design bases for these structures, systems, and components shall
reflect: (1) Appropriate consideration of the most severe of the
natural phenomena that have been historically reported for the site and
surrounding area, with sufficient margin for the limited accuracy,
quantity, and period of time in which the historical data have been
accumulated; (2) appropriate combinations of the effects of normal and
accident conditions with the effects of the natural phenomena; and (3)
the importance of the safety functions to be performed. Severe natural
phenomena may be reflected in a facility design basis through selection
and appropriate consideration of severe events that will then be the
basis for establishing the reference bounds for the design.
Accordingly, the questions in this ANPR will refer to the specific
values or ranges of values chosen for controlling parameters as
reference bounds for design associated with natural phenomena as ``the
bounding events selected for design purposes.''
GDC 17
General Design Criterion 17 governs electric power systems for
nuclear power plants designed in accordance with appendix A to 10 CFR
part 50. The draft version of this GDC published for comment in 1967
was proposed GDC 39, ``Emergency Power for Engineered Safety Features
(Category A)'' (32 FR 10213). Proposed GDC 39 read as follows:
Alternate power systems shall be provided and designed with
adequate independency, redundancy, capacity, and testability to
permit the functioning required of the engineered safety features.
As a minimum, the onsite power system and the offsite power system
shall each, independently, provide this capacity assuming a failure
of a single active component in each power system.
The public comments on proposed GDC 39 stated that the requirement
that offsite power must satisfy the ``single failure criterion'' was
impractical and asked the Commission to eliminate all reference to
offsite power. The resolution to the comment stated the following:
The criterion has been rewritten to make it clear that the
offsite power system need not meet the ``single failure criterion.''
Reference to offsite power has not been deleted because we believe
that offsite power is required to provide adequate assurance of
safety (see New Criterion 17). New Criterion 17 has been discussed
with the IEEE [Institute of Electrical and Electronics Engineers]
Subcommittee which is developing criteria for power requirements for
nuclear power units. The members of the subcommittee indicated that
the new criterion is acceptable and consistent with their
requirements.
Therefore, the Commission promulgated GDC 17 in appendix A to 10
CFR part 50 to state as follows:
An onsite electrical power system and an offsite electrical
power system shall be provided to permit functioning of structures,
systems, and components important to safety. The safety function for
each system (assuming the other system is not functioning) shall be
to provide sufficient capacity and capability to assure that (1)
specified acceptable fuel design limits and design conditions of the
reactor coolant pressure boundary are not exceeded as a result of
anticipated operational occurrences and (2) the core is cooled and
containment integrity and other vital functions are maintained in
the event of postulated accidents.
The onsite electrical power sources, including the batteries,
and the onsite electrical distribution system, shall have sufficient
independence, redundancy, and testability to perform their safety
functions assuming a single failure.
Electrical power from the transmission network to the switchyard
shall be supplied by two physically independent transmission lines
(not necessarily on separate rights of way) designed and located so
as to suitably minimize the likelihood of their simultaneous failure
under operating and postulated accident and environmental
conditions. Two physically independent circuits from the switchyard
to the onsite electrical distribution system shall be provided. Each
of these circuits shall be designed to be available in sufficient
time following a loss of all onsite alternating current power
sources and the other offsite electrical power circuit, to assure
that specified acceptable fuel design limits and design conditions
of the reactor coolant pressure boundary are not exceeded. One of
these circuits shall be designed to be available within a few
seconds following a loss-of-coolant accident to assure that core
cooling, containment integrity, and other vital safety functions are
maintained.
Provisions shall be included to minimize the probability of
losing electrical power from any of the remaining sources as a
result of, or coincident with, the loss of power generated by the
nuclear power unit, the loss of power from the transmission network,
or the loss of power from the onsite electrical power sources.
Section 8.2, ``Offsite Power System,'' of NUREG-75/087, ``Standard
Review Plan for the Review of Safety Analysis Reports for Nuclear Power
Plants: LWR Edition'' (SRP), published May 1980, and NUREG-0800,
originally published November 1975 with the most current revision
published May 2010, provide the review guidelines and acceptance
criteria for the offsite power system. Similarly, Section 8.3 of the
SRP provides the review guidelines and acceptance criteria for the
onsite ac power system. For nuclear power plants that were licensed
before GDC 17 applied, the plant-specific PDC, which are set forth in
the Updated Final Safety Analysis Report, provide the applicable design
criteria. A significant fraction of currently operating nuclear power
facilities were licensed in accordance with plant-specific PDC rather
than the GDC.
B. Station Blackout Rule
The availability of ac electrical power is essential for the safe
operation and accident recovery of commercial nuclear power plants. The
plant itself or offsite power sources normally supply this power
through the plant switchyard, through which the plant is connected to
the electrical grid. The term SBO is defined in 10 CFR 50.2 as follows:
Station blackout (SBO) means the complete loss of alternating
current (ac) electric power to the essential and nonessential
switchgear buses in a nuclear power plant (i.e., loss of offsite
electric power system concurrent with turbine trip and
unavailability of the onsite emergency ac power system). Station
blackout does not include the loss of available ac power to buses
fed by station
[[Page 16178]]
batteries through inverters or by alternate ac sources as defined in
10 CFR 50.2, nor does it assume a concurrent single failure or
design basis accident (DBA). At single unit sites, any emergency ac
power source(s) in excess of the number required to meet minimum
redundancy requirements (i.e., single failure) for safe shutdown
(non-DBA) is assumed to be available and may be designated as an
alternate power source(s) provided the applicable requirements are
met. At multi-unit sites, where the combination of emergency ac
power sources exceeds the minimum redundancy requirements for safe
shutdown (non-DBA) of all units, the remaining emergency ac power
sources may be used as alternate ac power sources provided they meet
the applicable requirements. If these criteria are not met, station
blackout must be assumed on all the units.
Because many of the safety systems relied upon for reactor core
decay heat removal and containment heat removal are dependent on ac
power, the consequences of an SBO could be significant. In the event of
an SBO, the capability to cool the reactor core is dependent on the
availability of systems that do not rely upon ac power from the
essential or nonessential switchgear buses for a specified time, and on
the ability to restore ac power within the specified time.
Unavailability of power can have a significant adverse impact on a
plant's ability to achieve and maintain safe-shutdown conditions. In
fact, risk analyses performed for nuclear power plants indicate that
the loss of all ac power can be a significant contributor to the risk
associated with plant operation, contributing more than 70 percent of
the overall risk at some plants. Therefore, the frequency of a loss of
offsite power (LOOP) and the time for subsequent restoration of offsite
power are important inputs to plant risk models, and these inputs must
reflect current industry performance in order for plant risk models to
accurately estimate the risk associated with LOOP-initiated scenarios.
One important subset of LOOP-initiated scenarios involves SBO
situations in which the affected plant achieves safe shutdown by
relying on components that are not ac powered, such as turbine- or
diesel-driven pumps. Thus, the reliability of such components, dc
battery depletion times, and characteristics of offsite power
restoration are important in determining risk from an SBO.
The SBO rule was developed based on insights gained from several
plant-specific probabilistic safety studies; operating experience; and
reliability, accident sequence, and consequence analyses completed
between 1975 and 1988. One such study, WASH-1400, ``Reactor Safety
Study,'' issued in 1975, indicated that SBO could be an important
contributor to the total risk from nuclear power plant accidents. In
1980, the Commission designated the issue of SBO as Unresolved Safety
Issue A-44, ``Station Blackout.'' The technical findings of the staff's
studies of the SBO issue are presented in NUREG-1032, ``Evaluation of
Station Blackout Accidents at Nuclear Power Plants, Technical Findings
Related to Unresolved Safety Issue A-44,'' June 1988.
The final rule containing SBO requirements was published in the
Federal Register (53 FR 23203) on July 21, 1988. The Commission issued
the SBO rule based on operating experience suggesting that both onsite
emergency ac power systems and offsite power from the transmission
network might be less reliable than originally anticipated, even for
plants designed to meet GDC 17 of appendix A to 10 CFR part 50. The
objective of the rule is to reduce the risk of severe accidents
resulting from SBO by maintaining highly reliable ac electric power
systems and, as additional defense-in-depth, assuring that plants can
cope with an SBO for a specified duration. NRC guidance for
implementing the SBO rule can be found in Regulatory Guide 1.155,
``Station Blackout,'' August 1988 (RG 1.155), which endorses Nuclear
Management and Resources Council (NUMARC) 8700, ``Guidelines and
Technical Bases for NUMARC Initiatives Addressing Station Blackout at
Light Water Reactors,'' November 1987. Additional background regarding
the SBO rule, its basis, and NRC guidance relating to SBO is referenced
within RG 1.155.
The SBO rule requires that nuclear power plants have the capability
to withstand an SBO and maintain core cooling and containment integrity
for a specified duration. The specified SBO duration for a plant is
determined based on (1) the redundancy of the onsite emergency ac power
sources, (2) the reliability of the onsite emergency ac power sources,
(3) the expected frequency of LOOP at the particular site, and (4) the
probable time needed to restore offsite power. The assumption used for
a LOOP at a plant site was an initiating event resulting from a
switchyard-related or grid-related event due to random faults, or an
external event, such as a grid disturbance, or weather events such as
high winds, snow, and ice loading that affects the offsite power system
either throughout the grid or at the plant. During the development of
the current SBO rule, it was concluded that there was a sufficiently
low likelihood of a LOOP generated by a fire, flood, or seismic
activity and that preexisting licensing requirements specified
sufficient protective measures such that LOOPs from such causes need
not be considered under the SBO rule requirements (see NUREG-1032 and
NUREG/CR-3226 for further detail).
In order to meet the requirements of the SBO rule and depending on
the station's existing capability, some stations were modified (i.e.,
by adding an alternate ac power source or increasing the capacity of
the station batteries, plant/instrument air system, or condensate
storage tank) in order to cope with the longer station blackout
duration. In addition, licensees enhanced station procedures and
training for restoring both offsite and onsite ac power sources. The
NRC and its licensees also increased their emphasis on establishing and
maintaining high reliability of onsite emergency power sources. The SBO
rule does not require systems and equipment used to cope with SBO to
meet 10 CFR part 50 quality assurance requirements for safety-related
equipment; instead, Appendix A of RG 1.155 provides the applicable
quality assurance guidance for non-safety systems and equipment used to
meet the SBO rule requirements.
Once the NRC has approved the ``specified duration'' of an SBO and
the coping analysis for a particular facility, the SBO rule does not
require licensees to update either the specified duration or the coping
analyses. However, the parameters that were used for inputs into both
the determination of the specified duration and the SBO coping analysis
are subject to change over time. These parameters include the number of
LOOP events expected at a particular site, recovery time for offsite
power, frequency of grid blackout events, and diesel generator
reliability. Changes to these parameters may have a significant effect
on the SBO duration and coping analyses originally performed by the
licensees. Nonetheless, if the NRC determines that a licensee's plans
for coping with an SBO are no longer adequate, the NRC could require a
licensee to modify its SBO plans or related equipment as necessary, so
long as the NRC satisfies the requirements of the Backfit Rule (10 CFR
50.109).
C. Petition for Rulemaking on Station Blackout Due to Coronal Mass
Ejection
The NRC has received a petition for rulemaking (PRM-50-96) from
Thomas Popik (the petitioner) that deals with long-term cooling and
unattended water makeup of SFPs due to potential long term grid loss
stemming from extreme
[[Page 16179]]
solar activity (76 FR 26223, dated May 6, 2011). The petitioner
believes that a widespread and prolonged grid outage of a year or
longer is possible and could result in degradation of societal
infrastructure to the extent that normal, commercial deliveries of
diesel fuel to reactor sites could not be relied upon. In this
scenario, grid failure might lead to a delayed SBO when onsite fuel for
emergency diesel generators was exhausted. The NRC has not yet
completed its evaluation of PRM-50-96 and it is unclear whether there
are any implications for the SBO rulemaking activity which is the
subject of this ANPR. Persons interested in the NRC action on PRM-50-96
may follow the NRC activities at the regulations.gov Web site under the
docket heading NRC-2011-0069. Pending further evaluation of PRM-50-96,
the SBO rulemaking activity will proceed independently.
D. Mitigating Strategies
Following the terrorist attacks of September 11, 2001, the NRC
ordered licensees to develop and implement specific guidance and
strategies to maintain or restore core cooling, containment, and SFP
cooling capabilities using existing or readily available resources that
can be effectively implemented under the circumstances associated with
loss of large areas of the plant due to explosions or fire. After
further development, these requirements were imposed as license
conditions for individual licensees and formalized in the rulemaking of
March 27, 2009, in 10 CFR 50.54(hh)(2) (74 FR 13969). Events at the
Fukushima Dai-ichi Nuclear Power Station following the March 11, 2011,
earthquake and tsunami highlighted the further potential benefits for
these same strategies to mitigate the effects of prolonged SBOs or
other events that may challenge core cooling, containment, and spent
fuel pool cooling.
IV. Discussion and Request for Public Comment
A. Advance Notice of Proposed Rulemaking Purpose
In its SRM on SECY-11-0124, the Commission directed the staff to
initiate a rulemaking to address SBO by means of an ANPR. Accordingly,
this ANPR's objective is to solicit external stakeholder input to
support the staff's efforts to assemble a regulatory basis for a rule
that amends SBO requirements. The Commission also encouraged the staff
to craft recommendations that continue to realize the strengths of a
performance-based system as a guiding principle. The Commission
indicated that, to be effective, approaches should be flexible and able
to accommodate a diverse range of circumstances and conditions. The
Commission stated that for consideration of events beyond the design
basis, a regulatory approach founded on performance-based requirements
will foster development of the most effective and efficient site-
specific mitigation strategies, similar to how the agency approached
the approval of licensee response strategies for the ``loss of large
area'' event addressed in 10 CFR 50.54(hh)(2).
The NRC is open to flexible, performance-based strategies to
address SBO mitigation. The following questions are intended to solicit
information that will support development of such a framework and
assembly of a complete and adequate regulatory basis for any rule
changes that are ultimately determined to be justified. In this
context, commenters are encouraged to provide information on any aspect
of SBO mitigation that would support this regulatory objective, whether
in response to an ANPR question or not.
B. Rulemaking Scope
The NRC would like external stakeholders to respond to the
following questions to support the NRC's efforts to define the scope of
the regulatory framework.
1. Recognizing the uncertainties associated with natural phenomena
and in the context of establishing a set of events upon which to base
reference bounds for design, should SBO equipment be designed to
withstand natural phenomena which the facility is not already designed
to withstand, and should SBO mitigation strategies consider such
natural phenomena? What severity of natural phenomena should be
considered (e.g., length of return period or duration of the
phenomena)? For example, flooding risks are of concern due to a
``cliff-edge'' effect, in that the safety consequences of a flooding
event may increase sharply with only a small increase in the flooding
level. Therefore, to address uncertainties for SBO events and to build
in additional defense-in-depth margin to mitigate SBO for such events,
should analysis of an SBO consider a flood elevation at some prescribed
level above the level for which the plant is designed? If so, what
criteria should be used to establish the prescribed level? What is the
basis for your position?
2. If such an analysis (per the above question) is warranted, what
margin in addition to that included in the reference bounds for design
should be considered? For existing facilities, should such an analysis
include factors such as the existence of nearby dams or water sources?
3. For events that do not fall within the reference bounds for
design, but may result in SBO conditions, it may be necessary for
licensees to take early action in order to increase the potential for
successful mitigation. Recognizing that there are several actions that
take time during such events that include, but are not limited to (1)
the need to properly identify and diagnose the event or situation, (2)
the need to make the decision to implement actions or strategies to
mitigate existing or imminent SBO conditions, and (3) the time for
licensees to implement the strategies once the decision is made; what
time constraints do stakeholders understand to be important in
developing SBO mitigation requirements? For example, what should be the
coping time with no mitigation for SBO conditions given time
constraints that include the time to (1) identify and determine the
need to take mitigative actions and (2) implement these strategies
under worst case conditions? How long should mitigation strategies be
expected to be deployed before the receipt of offsite assistance? If
certain mitigation actions must be taken early in the event to avert
core damage, how should those actions be determined and how should the
time when they must be performed be determined?
4. Similar to question B.2, but from a broader perspective of
establishing all the new SBO mitigation requirements: Different regions
of the United States have different natural phenomena that are more
significant in terms of potentially creating SBO conditions. Should the
NRC construct a new regulatory framework containing criteria that
enable licensees to establish the set of natural phenomena of concern
for their sites? If so, what criteria should be used to determine
whether an event needs to be considered at a particular site? Please
provide the basis for your position.
5. The current requirements in 10 CFR 50.63 for SBO are ``unit-
specific,'' meaning that the total loss of all ac is not assumed to
extend to all the power reactors at a given site. Based on the lessons
learned from the Fukushima Dai-ichi event, the NRC believes the SBO
requirements may need to be expanded to consider an SBO for the entire
site (i.e., assume the SBO condition occurs to all the units for multi-
unit sites). What are stakeholder views on this matter, and how should
it
[[Page 16180]]
be addressed in the new SBO rule? Please provide the basis for your
position.
6. The current provisions in 10 CFR 50.63 require a facility to
withstand, for a specified duration, and recover from an SBO as defined
in 10 CFR 50.2. Should the new SBO rule require long-term cooling and
water makeup to SFPs during an SBO? Please provide the basis for your
position.
7. Should the SBO rule address how external events would affect the
``specific duration'' of the SBO and the associated coping time?
Specifically:
a. Should the NRC require consideration of the likelihood of
external events that fall outside the bounding events selected for
design purposes in the determination of SBO specified duration, or the
capability to cope with an SBO for the specified duration, or both? If
so, what should the rule require? What is the basis for your position?
b. Should the NRC require consideration of additional margin in the
probability or magnitude (or both) of bounding events selected for
design purposes with respect to natural phenomena (e.g., design basis
external flood plus 10 additional feet or extending the ability to
withstand the total loss of ac power for longer durations) in the
determination of SBO specified duration or the capability to cope with
an SBO during the specified duration, or both? Provide any proposed
rule provisions and a discussion that supports your position.
c. Should the SBO rule require applicants and licensees to address
a more challenging condition such as the total loss of all ac,
including ac from the dc batteries through inverters? Please provide
the basis for your position.
8. If new requirements as discussed in this section should be
imposed for existing licensees or with respect to existing certified
designs, what sort of benefits or costs do stakeholders estimate could
be incurred?
C. Rulemaking Objectives/Success Criteria
The NRC is considering whether enhancements to current SBO
requirements are advisable in order to consider natural phenomena
beyond the plant-specific events selected as bounding for design
purposes, even if the plant's design basis meets the NRC requirements
and guidance for natural phenomena that are applicable to new plant
applications. The NRC would like stakeholder views on specific
regulatory objectives and success criteria for the potential
rulemaking, as follows:
1. What specific objectives should the SBO rule be designed to
achieve?
a. For example, should the objective of the SBO rule be to
significantly reduce the frequency of core damage from a prolonged SBO,
or would it be better to focus on the reduction of the frequency of
large early release of radiation for low probability external events
that result in SBO conditions? Please provide the basis for your
position.
b. Alternatively, should the SBO rule be designed to achieve a more
qualitative safety objective such as increasing, as a defense-in-depth
measure, requirements for the mitigating strategies to cope with
prolonged SBO conditions stemming from events that do not fall within
the reference bounds for the design, assuming GDC 2 (or the
corresponding PDC) is satisfied? Please provide the basis for your
position.
c. Should the SBO rule provide increased assurance that the
facility can achieve and maintain a safe shutdown condition under SBO
conditions for a set of initiating events that lead to SBO conditions,
and as one way of doing this, enable licensees to use a criterion for
determining the set of conditions that apply to their plants or sites?
Please provide the basis for your position.
d. Should the NRC adopt an SBO rule that is more performance-based
and which would not specify the events that must be considered in
determining the SBO duration or the capability for coping with an SBO
of specified duration? Specifically should the NRC structure an SBO
rule as follows:
(1) Require each applicant and licensee to develop, implement, and
maintain SBO procedures that describe how the licensee will address the
following areas if the plant experiences an event that exceeds the
values or does not fall within the ranges of values chosen for the
reference bounds for the design of the facility:
(i) Communication with onsite personnel and offsite entities
providing support to mitigate the event;
(ii) Onsite actions necessary to enhance the capability of the
facility to mitigate the consequences of the loss of all ac power and
other equipment damage;
(iii) Dispersal of equipment and personnel, as well as rapid entry
into site protected areas for essential onsite personnel and offsite
responders who are necessary to mitigate the event; and
(iv) Recall of site personnel.
(2) Require each applicant and licensee to develop and implement
guidance and strategies intended to maintain or restore core cooling,
containment, and SFP cooling capabilities under the circumstances
associated with the loss of all ac power, from an event that does not
fall within the reference bounds chosen for the design of the facility,
including:
(i) Station blackout coping and power restoration activities;
(ii) Operations to mitigate fuel damage; and
(iii) Actions to minimize radiological release.
Please provide the basis for your position.
e. Recognizing that the SBO mitigation requirements could address a
set of events that fall outside the reference bounds for design of the
plant and may lead to SBO conditions, success criteria might be more
readily established. Should the rule establish success criteria or
requirements that apply as a function of the probability of the events?
For example, for the more probable/common SBO events, such as those
that 10 CFR 50.63 currently addresses, the current 10 CFR 50.63
requirements could largely remain in place. For the low probability,
high consequence, hazard-driven SBOs, a different set of success
criteria could be established that recognize the lower probabilities of
occurrence of these types of SBOs. Please provide the basis for your
position.
2. How should actions taken to address the staff's recommended
approach for NTTF Recommendation 4.2 be used to support the development
of SBO mitigation requirements within a coherent, integrated regulatory
framework? Provide a discussion that supports your position.
3. The NRC would like stakeholder's views on a regulatory approach
to SBO mitigation that conceptually follows the NTTF proposal in NTTF
Recommendation 4.1. Specifically, do stakeholders believe that the best
conceptual approach for SBO mitigation is to establish requirements for
an initial coping period (no ac power available), during which time
licensees establish mitigation strategies; followed by an interim
period during which time the mitigation strategies are employed for a
duration sufficient to enable offsite relief to arrive; followed by a
final phase where offsite relief has arrived and a stable shutdown
condition is established? Alternatively, if stakeholders have
alternative approaches or suggested changes to this conceptual
approach, please provide the basis for them.
The NRC notes that there is a close relationship between the SBO
mitigation requirements under consideration in this regulatory effort
and several other near-term actions
[[Page 16181]]
stemming from the Fukushima Dai-ichi event (and identified in SECY-11-
0124 and SECY-11-0137). Regulatory actions taken in response to these
other activities may have an impact on any regulatory actions taken to
address SBO. In this regard, the NRC would like stakeholder views on
the following:
4. Recognizing that SBO mitigation may rely upon Emergency
Operating Procedures (EOPs) and Severe Accident Management Guidelines
(SAMGs), how should regulatory actions taken to address NTTF
Recommendation 8 with regard to coordination of EOPs, SAMGs, and
Extensive Damage Mitigation Guidelines be best integrated with SBO
mitigation requirements to ensure that actions to address each of these
NTTF recommendations do not unduly overlap or inadvertently introduce
unnecessary redundancy, inconsistency, or other unintended
consequences?
5. Recognizing that the containment function is a key defense-in-
depth measure for SBO events, how should regulatory actions to address
NTTF Recommendation 5.1, which discusses installation of reliable
hardened containment vent systems for boiling water reactors with Mark
I and II containments designs, be integrated with potential SBO load-
shedding mitigation activities to ensure that actions to address each
of these NTTF recommendations do not unduly overlap or inadvertently
introduce unnecessary redundancy, inconsistency, or other unintended
consequences?
6. Recognizing the importance of SFP cooling and the need to
understand the condition of the SFP, how should regulatory actions
taken to address NTTF Recommendation 7.1, which addresses SFP
instrumentation, be integrated into SBO mitigation plans to ensure that
actions to address each of these NTTF recommendations do not unduly
overlap or inadvertently introduce unnecessary redundancy,
inconsistency, or other unintended consequences?
D. Functional Considerations and Requirements for Supporting
Structures, Systems, and Components and Procedures
An important element of a new set of SBO requirements would be
identifying the functions that need to be performed under SBO
conditions, since performance of these functions relates directly to
achieving the objectives of the rulemaking. Additionally, establishing
the functions that must be performed enables the identification of the
set of SSCs (SBO mitigation equipment) and supporting procedures,
guidelines, and strategies that would need to be employed. The NRC
considers the key safety functions identified below to be the essential
functions for SBO mitigation, and would like stakeholder's views on
whether this is the correct set:
1. Reactor core cooling;
2. Spent fuel pool cooling; and
3. Containment.
With regard to the requirements that would stem from identification
of the SBO mitigation functions, the NRC would like stakeholder views
on:
1. What requirements (e.g., design, inspection, testing, quality
assurance, corrective action) should be applied to the SBO mitigation
SSCs that perform the key safety functions to provide increased
assurance that the functions can be performed? What constitutes
increased assurance (i.e., what must be achieved with the additional
treatment requirements) for the mitigation of SBO conditions stemming
from either design basis events or from external events that exceed the
events chosen as bounding for design purposes? Please provide the basis
for your position.
2. What requirements for supporting procedures, guidelines,
strategies, and training should be included within the SBO rule (also
refer to question C.6)? Please provide the basis for your position.
3. Should the SBO rule address licensee staffing requirements for
SBO mitigation for an event involving more than a single unit (for
multi-unit sites)? Please provide the basis for your position.
4. Should the NRC require surveillance testing and limiting
conditions for operation for some or all equipment credited for
mitigating an SBO event? Alternatively, should the NRC use a different
approach for testing of SBO equipment, such as either specific testing
requirements in a new rule, use of 10 CFR 50.65 (Maintenance Rule), or
other existing plant processes? Please provide the basis for your
position.
5. Should the NRC require applicants and licensees to describe the
SSCs, supporting procedures, and programs used to implement the new SBO
requirements in the Final Safety Analysis Report? Alternatively, should
the NRC consider a special change control requirement for these SSCs,
procedures, and programs? If stakeholders agree that such a requirement
would be valuable, what criteria would be used to determine when
changes could be made without prior NRC review and approval?
6. If new requirements under the items above were to be imposed for
existing licensees or with respect to existing certified designs, what
sort of benefits and costs do stakeholders estimate could be incurred?
E. Applicability to NRC Licenses and Approvals
The NRC would apply any new SBO requirements to power reactors,
both currently operating and new reactors, and would like stakeholder
input on this aspect of the rule. Accordingly, the NRC envisions that
this would include (but not be limited to):
1. Nuclear power plants currently licensed under 10 CFR parts 50 or
52;
2. Nuclear power plants currently being constructed under
construction permits issued under 10 CFR part 50, or whose construction
permits may be reinstated;
3. Current and future applications for standard design
certification and standard design approval under 10 CFR part 52;
4. Future nuclear power plants whose construction permits and
operating licenses are issued under 10 CFR part 50;
5. Future nuclear power plants whose combined licenses are issued
under 10 CFR part 52, and
6. Future nuclear power plants that are manufactured under 10 CFR
part 52.
F. Relationship Between Existing Station Blackout Requirements in Title
10 of the Code of Federal Regulations, Section 50.63 and the New
Station Blackout Requirements
The NRC is considering how any new SBO requirements would relate to
the existing SBO requirements in 10 CFR 50.63, and has identified three
approaches:
1. Approach 1 (Base Case--Supplementary SBO Requirements): The new
SBO requirements would 1) address SBO issues which are separate from,
and address scenarios which go beyond, the existing 10 CFR 50.63
requirements; and 2) be added to the existing 10 CFR 50.63 SBO
requirements, possibly in a new section (e.g., 10 CFR 50.XX). This
approach would not change the existing 10 CFR 50.63 requirements, with
the exception of some conforming changes needed to ensure coordination
between the existing, unchanged 10 CFR 50.63 requirements, and the
newly-added SBO requirements.
2. Approach 2 (Unified SBO Requirements): The new SBO requirements
would: (1) Address SBO issues which are separate from, and address
scenarios which go beyond, the existing 10 CFR 50.63 requirements (same
as Element 1 of Approach 1); and (2) be integrated into a single rule,
[[Page 16182]]
representing a unified overall approach to SBO. This differs from
Approach 1 in that the NRC would develop new rule language that
presents a single, unified approach to SBO covering the full spectrum
of issues, accidents, plant conditions, and performance objectives that
each nuclear power plant must meet. The new rule would include the
current 10 CFR 50.63 requirements.
3. Approach 3 (Superseding SBO Requirements): The new SBO
requirements would envelope the full spectrum of issues, accidents,
plant conditions, and performance objectives that each nuclear power
plant must meet, so that the existing SBO requirements in 10 CFR 50.63
would be subsumed in the new rule. This approach differs from Approach
1 in that the new SBO requirements would address SBOs whose
characteristics and scope may be more ``severe'' than originally
envisioned in 10 CFR 50.63. Under Approach 3, the new SBO requirements
would entirely supersede and displace the existing SBO requirements in
10 CFR 50.63. All existing SBO requirements would be removed from 10
CFR 50.63 and licensees would be required to change their SBO licensing
bases (e.g., change or remove a Final Safety Analysis Report
description, a technical specification, or a license condition) to
comply with the new requirements.
The NRC therefore seeks stakeholder views on which of these options
is best suited for implementing new requirements recommended in
response to ANPR Sections B, C, and D, above. What is the basis for
your position?
G. Advisory Committee on Reactor Safeguards Recommendations
By letter dated October 13, 2011, the Advisory Committee on Reactor
Safeguards (ACRS) provided its recommendations concerning near-term
actions that should be taken without delay. With regard to the
mitigation of SBO, the ACRS recommended that:
Staff should also require licensees to provide an assessment of
capabilities to cope with an extended SBO, including system
vulnerabilities (e.g., reactor coolant pump seal qualifications) and
capabilities to mobilize and deliver offsite resources (e.g.,
portable generators, fuel supplies, water pumping equipment). This
information will inform staff interactions with the industry during
the rulemaking process and help develop guidance that can be applied
in the near term for enhanced confidence that each site has
identified their available options.
Accordingly, the NRC is interested in stakeholder feedback
regarding both current and projected future (i.e., considering other
actions that could stem from the staff's recommendation to address NTTF
Recommendation 4.2 as well as other relevant NTTF actions) capabilities
for coping with an extended SBO, including system vulnerabilities.
Additionally, the NRC would like stakeholder views concerning the
capabilities to mobilize and deliver offsite resources (e.g., portable
generators, fuel supplies, water pumping equipment) as contemplated by
both the NTTF and by the industry conceptual approach described in the
Nuclear Energy Institute (NEI) paper, ``An Integrated, Safety-Focused
Approach to Expediting Implementation of Fukushima Daiichi Lessons-
Learned,'' dated December 16, 2011.
V. Public Meeting
The NRC plans to hold a category 3 public meeting with stakeholders
during the ANPR public comment period. The public meeting is intended
to provide a forum to discuss the ANPR with external stakeholders and
inform stakeholder views on SBO mitigation to enable stakeholders to
provide feedback. The meeting is not intended for the NRC to receive
comments and instead the NRC will encourage stakeholders to provide any
comments in written form. To support full participation of
stakeholders, the staff plans to provide teleconferencing and Webinar
access. The NRC does not intend to transcribe the meeting. The NRC will
issue the public meeting notice at least 10 days prior to the public
meeting. Stakeholders should monitor the NRC's public meeting Web site:
http://www.nrc.gov/public-involve/public-meetings/index.cfm.
VI. Rulemaking Process
The NRC does not intend to provide detailed comment responses for
information provided in response to this ANPR. The NRC will consider
timely comments on this ANPR in the rule development process. If the
NRC ultimately develops a proposed rule on SBO requirements, any notice
of proposed rulemaking will provide an opportunity to comment on the
proposed rule, and the NRC will document its responses to any comments
received in accordance with the notice. If supporting guidance is
developed for a proposed rule, stakeholders will have an opportunity to
provide feedback on the guidance as well.
VII. Availability of Supporting Documents
The following documents provide additional background and
supporting information regarding this rulemaking activity. The
documents can be found using any of the methods provided in the table.
Instructions for accessing ADAMS were provided under the ADDRESSES
section of this document.
------------------------------------------------------------------------
ADAMS Accession
No./Web link/
Date Document Federal Register
citation
------------------------------------------------------------------------
July 12, 2011................. SECY-11-0093, ``The ML111861807.
Near-Term Report and
Recommendations for
Agency Actions
following the Events
in Japan''.
August 19, 2011............... Staff Requirements-- ML112310021.
SECY-11-0093, ``The
Near-Term Report and
Recommendations for
Agency Actions
following the Events
in Japan''.
July 26, 2011................. PRM-50-101, Petition http://
for Rulemaking to www.regulations
Revise 10 CFR 50.63. .gov by
searching on
Docket ID NRC-
2011-0189.
September 9, 2011............. SECY-11-0124, ML11245A127,
``Recommended Actions ML11245A144.
to be Taken Without
Delay from the Near-
Term Task Force
Report''.
October 18, 2011.............. Staff Requirements-- ML112911571.
SECY-11-0124,
``Recommended Actions
to be Taken Without
Delay From The Near-
Term Task Force
Report''.
October 3, 2011............... SECY-11-0137, ML11272A203,
``Prioritization of ML11269A204.
Recommended Actions
to be Taken in
Response to Fukushima
Lessons Learned''.
December 15, 2011............. Staff Requirements-- ML113490055.
SECY-11-0137,
``Prioritization of
Recommended Actions
to be Taken in
Response to the
Fukushima Lessons
Learned''.
[[Page 16183]]
January 28, 1971.............. SECY-R-143, ML072420278.
``Amendment to Title
10 of the Code of
Federal Regulations
(10 CFR) Section 50--
General Design
Criteria for Nuclear
Power Plants''.
July 11, 1967................. General Design 32 FR 10213.
Criteria for Nuclear
Power Plant
Construction Permits.
May 1980...................... NUREG-75/087, Standard ML042080088.
Review Plan for the
Review of Safety
Analysis Reports for
Nuclear Power Plants:
LWR Edition.
May 2010...................... NUREG-0800, Standard ML100740246.
Review Plan for the
Review of Safety
Analysis Reports for
Nuclear Power Plants:
LWR Edition, Section
8.2, ``Offsite Power
System''.
October 1975.................. WASH-1400 (NUREG-75/ ML072350618.
014), Reactor Safety
Study: An Assessment
of Accident Risks in
U.S. Commercial
Nuclear Power Plants.
June 1988..................... NUREG-1032, Accessible from
``Evaluation of U. S.
Station Blackout Department of
Accidents at Nuclear Energy's
Power Plants, Information
Technical Findings Bridge at http:/
Related to Unresolved /www.osti.gov/
Safety Issue A-44''. bridge/
purl.cover.jsp?
purl=/5122568-
gvK0cy/
5122568.pdf.
March 21, 1986................ Notice of Proposed 51 FR 9829.
Rulemaking: Station
Blackout (10 CFR
50.63).
June 21, 1988, Sept. 22, 1998. Station Blackout (10 53 FR 23203, 63
CFR 50.63). FR 50480.
March 27, 2009................ 10 CFR 50.54(hh)(2)... 74 FR 13969.
March 23, 2011................ Tasking Memorandum ML110950110.
from Chairman Gregory
B. Jaczko to the
Executive Director
for Operations
(COMGBJ-11-0002): NRC
Actions Following the
Events in Japan.
November 2011................. INPO-11-005, ``Special ML11347A454.
Report on the Nuclear
Accident at the
Fukushima Dai-ichi
Nuclear Power
Station''.
March 15, 2011................ PRM-50-96............. http://www.regulations.gov by
searching on
Docket ID NRC-
2011-0069.
76 FR 26223.
February 20, 1971............. Amendment to 10 CFR 36 FR 3256.
Part 50--General
Design Criteria For
Nuclear Power Plants.
July 6, 1970.................. Status Report On ML003726549.
General Design
Criteria.
August 28, 2007............... Appendix A to Part 50-- 72 FR 49505.
General Design
Criteria for Nuclear
Power Plants.
April 1, 2002................. Staff Guidance on ML020920464.
Scoping of Equipment
Relied on to Meet the
Requirements of the
Station Blackout
(SBO) Rule (10 CFR
50.63) for License
Renewal (10 CFR
54.4(a)(3)).
August 28, 2007............... Final Rule: Licenses, 72 FR 49352.
Certifications, and
Approvals for Nuclear
Power Plants.
December 16, 2011............. NEI Submittal of An ML11353A008.
Integrated, Safety-
Focused Approach to
Expediting
Implementation of
Fukushima Daiichi
Lessons Learned.
October 13, 2011.............. Initial ACRS Review ML11284A136.
of: (1) the NRC Near-
Term Task Force
Report on Fukushima
and (2) Staff's
Recommended Actions
to be Taken Without
Delay.
August 1988................... NRC Regulatory Guide ML003740034.
1.155, ``Station
Blackout''.
November 1987................. ``Guidelines and ML12074A007.
Technical Bases for
NUMARC Initiatives
Addressing Station
Blackout at Light
Water Reactors,''
NUMARC 8700.
------------------------------------------------------------------------
Dated at Rockville, Maryland, this 12th day of March 2012.
For the Nuclear Regulatory Commission.
R.W. Borchardt,
Executive Director for Operations.
[FR Doc. 2012-6665 Filed 3-19-12; 8:45 am]
BILLING CODE 7590-01-P