[Federal Register Volume 77, Number 54 (Tuesday, March 20, 2012)]
[Proposed Rules]
[Pages 16175-16183]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-6665]


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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.

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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: Carol.Gallagher@nrc.gov.
     Mail comments to: Secretary, U.S. Nuclear Regulatory 
Commission, Washington, DC 20555-0001, ATTN: Rulemakings and 
Adjudications Staff.
     Email comments to: Rulemaking.Comments@nrc.gov. 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: Timothy.Reed@nrc.gov.

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 PDR.Resource@nrc.gov.
     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