[Federal Register Volume 90, Number 87 (Wednesday, May 7, 2025)]
[Rules and Regulations]
[Pages 19247-19250]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-07899]
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NUCLEAR REGULATORY COMMISSION
10 CFR Part 50
[NRC-2011-0069]
Long-Term Cooling and Unattended Water Makeup of Spent Fuel Pools
AGENCY: Nuclear Regulatory Commission.
ACTION: Discontinuation of rulemaking activity; denial of petition for
rulemaking.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is discontinuing
a rulemaking activity, ``Long-Term and Unattended Water Makeup of Spent
Fuel Pools,'' and denying a petition for rulemaking. The petitioner
requested that the NRC amend its regulations to require that nuclear
power plant licensees ensure long-term cooling and unattended water
makeup of spent fuel pools (SFPs). The purpose of this action is to
inform members of the public that this rulemaking activity is being
discontinued and to provide a brief discussion of the NRC's decision to
discontinue the rulemaking and deny the aspects of the petition not
previously addressed by the NRC.
DATES: Effective May 7, 2025.
ADDRESSES: Please refer to Docket ID NRC-2011-0069 when contacting the
NRC about the availability of information for this action. You may
obtain publicly available information related to this action by any of
the following methods:
Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC-2011-0069. Address
questions about NRC dockets to Helen Chang; telephone: 301-415-3228;
email: [email protected]. For technical questions, contact the
individuals listed in the FOR FURTHER INFORMATION CONTACT section of
this document.
NRC's Agencywide Documents Access and Management System
(ADAMS): You may obtain publicly available documents online in the
ADAMS Public Documents collection at https://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``Begin Web-based ADAMS
Search.'' For problems with ADAMS, please contact the NRC's Public
Document Room (PDR) reference staff at 1-800-397-4209, at 301-415-4737,
or by email to [email protected]. For the convenience of the reader,
instructions about obtaining materials referenced in this document are
provided in the ``Availability of Documents'' section.
NRC's PDR: The PDR, where you may examine and order copies
of publicly available documents, is open by appointment. To make an
appointment to visit the PDR, please send an email to
[email protected] or call 1-800-397-4209 or 301-415-4737, between 8
a.m. and 4 p.m. eastern time, Monday through Friday, except Federal
holidays.
FOR FURTHER INFORMATION CONTACT: Christopher Prescott, Office of
Nuclear Material Safety and Safeguards, telephone: 301-287-9452; email:
[email protected]; or Jason Paige, Office of Nuclear Reactor
Regulation, telephone: 301-415-1474; email: [email protected]. Both
are staff of the U.S. NRC, Washington, DC 20555-0001.
SUPPLEMENTARY INFORMATION:
I. Background
The NRC received a petition for rulemaking (PRM), dated March 14,
2011, submitted by Thomas Popik on behalf of the Foundation for
Resilient Societies. On March 15, 2011, the petition was docketed by
the NRC as PRM-50-96. The petitioner requested that the NRC amend its
regulations to require facilities licensed by the NRC under part 50,
``Domestic Licensing of Production and Utilization Facilities,'' of
title 10 of the Code of Federal Regulations (10 CFR) to address
concerns about the effects of a long-term commercial grid outage on the
long-term cooling and unattended water makeup of SFPs. The petitioner
asserted that the North American commercial electric power grids are
vulnerable to a prolonged outage caused by extreme space weather, such
as coronal mass ejections and associated geomagnetic disturbances and
therefore cannot be relied on to provide continual power for active
cooling and/or water makeup of SFPs. Moreover, the petitioner stated
that existing means of onsite backup power are designed to operate for
only a few days, while spent fuel requires active cooling for several
years after removal of the fuel rods from the reactor core. The
petitioner suggested the following rule language for 10 CFR part 50:
[[Page 19248]]
Licensees shall provide reliable emergency systems to provide
long-term cooling and water makeup for spent fuel pools using only
on-site power sources. These emergency systems shall be able to
operate for a period of two years without human operator
intervention and without offsite fuel resupply. Backup power systems
for spent fuel pools shall be electrically isolated from other plant
electrical systems during normal and emergency operation. If
weather-dependent power sources are to be used, sufficient water or
power storage must be provided to maintain continual cooling during
weather conditions which may temporarily constrict power generation.
On May 6, 2011, the NRC published a notice of receipt and request
for public comment for this petition in the Federal Register (76 FR
26223). The public comment period closed on July 20, 2011, and the NRC
received 97 public comments. After reviewing public comments and
evaluating other ongoing activities, the NRC performed a preliminary
review and analysis to ascertain the validity, accuracy, and efficacy
of the petitioner's technical assertions and proposed amendment of 10
CFR part 50.
On December 18, 2012, the NRC closed the docket for PRM-50-96 by
publishing a document in the Federal Register (77 FR 74788) stating
that the NRC would, in a phased approach, consider the PRM issues in
the NRC rulemaking process. This document also stated that the NRC
would monitor the progress of the rulemaking efforts that would
eventually become the ``Mitigation of Beyond-Design-Basis Events''
(MBDBE) final rule to determine whether the requirements established
therein would address the issues raised in PRM-50-96.
On August 9, 2019, the NRC published the MBDBE final rule (84 FR
39684), which partially resolved this PRM because it requires, in part,
that licensees have plans to acquire and use offsite assistance and
resources to support the functions of maintaining or restoring core
cooling, containment, and SFP cooling capabilities during an extended
loss of alternating current power. Furthermore, in the preamble for the
MBDBE final rule, the Commission stated that the NRC would address the
remaining issues in PRM-50-96 following the completion of the MBDBE
rulemaking. A discussion of the NRC's decision to discontinue this
rulemaking activity and deny PRM-50-96 is provided in section II of
this document.
II. Discussion
A. Basis for Denying the Petition and Discontinuing Rulemaking Activity
The NRC will discontinue rulemaking activities associated with PRM-
50-96 and deny aspects of the petition related to the two issues that
were not fully addressed by the MBDBE final rule. The first such issue
was that current NRC regulations do not require power reactor licensees
to undertake mitigating efforts for prolonged grid failure scenarios
that could be caused by geomagnetically induced currents resulting from
an extreme solar storm. The second issue was the petitioner's request
that licensees be required to have emergency systems to assure long-
term cooling and water makeup of SFPs capable of operating for a period
of 2 years without human intervention and without offsite fuel
resupply. These concerns not resolved by the MBDBE final rule have been
addressed by other industry and government action, as described below.
Since 2012, there have been improvements in electrical grid
resilience to geomagnetic disturbances and overall knowledge regarding
the potential impacts of geomagnetic disturbances that address, in
large part, the unresolved aspects of the PRM. The current
understanding is that geomagnetic disturbances may cause localized grid
failures but are unlikely to cause a widespread, long-term grid
failure. This is demonstrated by improvements in space weather induced
geoelectric field modeling through research sponsored by the United
States Geological Survey, National Oceanic and Atmospheric
Administration (NOAA), and the National Aeronautics and Space
Administration (see examples listed in section III of this document),
in conjunction with industry efforts to quantify the associated risk to
the power grid such as the 2017 Electric Power Research Institute
(EPRI) report, ``Magnetohydrodynamic Electromagnetic Pulse Assessment
of the Continental U.S. Electric Grid: Voltage Stability Analysis.''
Additionally, the Federal Energy Regulatory Commission has worked to
improve the resiliency of the grid to geomagnetic disturbances by
implementing improved standards such as the North American Electric
Reliability Corporation (NERC) TPL-007-4, ``Transmission System Planned
Performance for Geomagnetic Disturbance Events.'' Currently, more than
80 percent of extra high voltage transformers are resistant against the
effects of geomagnetically induced currents. With TPL-007-4 in effect,
a widespread, long-term grid failure is unlikely because such grid
failure is largely driven by failure of extra high voltage transformers
that are now subject to standards for vulnerability assessments and
associated corrective action plans.
Moreover, improvements in space weather monitoring allow grid
operators to take actions that can protect grid equipment. Grid
operators are directly engaged with NOAA--Space Weather Prediction
Center (SWPC). For example, the SWPC provides grid operators with
timely notification of impending geomagnetic storms, forecasts, and
real-time onset, strength, and duration information. This information
allows active mitigation of potential space weather impacts. As such,
damage to transformers and other vital equipment is less likely to
occur. In 2014, the White House Office of Science and Technology Policy
established the Space Weather Operations, Research, and Mitigation
(SWORM) Subcommittee to address operations, research, and mitigation of
space weather issues. The first National Space Weather Strategy and
Action Plan (NSW-SAP) in 2015 established the framework for a
government-wide approach to space weather. In 2019, building on this
coordinated effort and supported by Executive Order 13744,
``Coordinating Efforts to Prepare the Nation for Space Weather
Events,'' the SWORM developed a revised NSW-SAP that improved and
clarified ongoing and future space weather activities. The 2023
Implementation Plan of the National Space Weather Strategy serves as a
roadmap for implementing the 2019 NSW-SAP over the following 5 years
and supports continued grid management activities. Therefore, the
petitioner's concerns of a potential geomagnetic disturbance resulting
in 2-year grid failure have been addressed.
The second issue raised in the PRM regarding licensees' capability
to have adequate fuel supply to provide continual power for active
cooling and/or water makeup of SFPs during a grid failure resulting
from a geomagnetic disturbance has also been addressed. The NRC has
reasonable assurance of an onsite 7-day fuel supply to maintain safe
shutdown; that offsite diesel fuel can be obtained in the event of such
a grid failure through existing industry contracts; and that Federal,
State, and local organizations have the capability to provide fuel
supplies, if needed. The NRC's regulations in 10 CFR part 50, appendix
A, establish the minimum requirements for the principal design criteria
for water-cooled nuclear power plants. Criterion 17, ``Electric Power
Systems,'' requires that onsite electric power supplies, and the onsite
electric distribution system, to have sufficient independence,
redundancy, and testability to perform their safety
[[Page 19249]]
functions, eliminating any single points of failure. The general design
criteria in 10 CFR part 50, appendix A, are considered to be generally
applicable to other types of nuclear power units and are intended to
provide guidance for the development of principal design criteria for
such other units. The NRC guidance in Regulatory Guide 1.137, Revision
2, ``Fuel Oil Systems for Emergency Power Supplies,'' and industry
standards such as American National Standards Institute/American
Nuclear Society 59.51, ``Fuel Oil Systems for Safety-Related Emergency
Diesel Generators,'' recommend that sites should maintain onsite a
minimum of a 7-day fuel supply. Most sites include additional fuel
storage capacity. The Federal Emergency Management Agency's National
Response Framework identifies roles and responsibilities in the
Emergency Support Function #12--Energy, and the Emergency Support
Function #7--Logistics, to ensure adequate planning and subsequent
support to jurisdictions, citizens, nongovernmental organizations, and
businesses in the case of energy emergencies and disruptions. Both
Federal and State emergency response organizations use the National
Response Framework and have the organizational structure and authority
to ensure that nuclear power plants receive fuel resupplies.
Furthermore, onsite equipment to provide makeup water to the SFP would
not be affected by a grid failure resulting from a geomagnetic
disturbance because emergency equipment like stand-alone diesel pumps
do not run on electricity.
The NRC concludes that there is no safety concern necessitating the
changes requested by the petitioner.
B. Discussion of Public Comments Received
The NRC received 97 comment submissions on PRM-50-96. The NRC
considered all the comments on the PRM and the comments from the MBDBE
rulemaking that were not addressed by the final rule. Of the 97 comment
submissions, 58 were form letter submissions. One comment came from an
industry group, and the remainder were either anonymous submissions or
from individuals.
For PRM-50-96, the only comment submission recommending the denial
of the petition came from the Nuclear Energy Institute. The majority of
comments supporting the petition were in a form letter format and did
not provide additional technical information. The common concerns
raised included long-term grid failure, loss of operators, inadequate
or unreliable emergency generator fuel supply, SFP fires, solar flares,
electromagnetic pulse (EMP) attack, and cyberattack.
Since the events of September 11, 2001, the NRC has actively
addressed cybersecurity threats by establishing requirements in 2009 to
protect safety, security, and emergency preparedness (SSEP) functions
at commercial nuclear power plants. Specifically, 10 CFR 73.54,
``Protection of digital computer and communication systems and
networks,'' requires commercial nuclear power plant licensees to
protect digital computer and communication systems and networks
associated with SSEP functions against cyberattacks. Commercial nuclear
power plant licensees submitted cybersecurity plans and an
implementation schedule that were reviewed and approved by the NRC in
2010. Since then, licensees completed full implementation of their
cybersecurity programs from 2017 to 2020. During this period, the NRC
conducted inspections verifying compliance with the requirements and
the implementation schedule. Cybersecurity inspections are still
ongoing to make sure those systems required for SSEP are protected,
protections are maintained, and that upgrades are analyzed to ensure
that adequate protections are in place prior to installation. Licensee
cybersecurity programs are required to provide defense-in-depth
protective strategies to ensure the capability to detect, respond to,
and recover from cyberattacks, and these aspects are verified every 2
years via inspections.
Multiple comments raised the issue of the impacts of geomagnetic
disturbances from solar flare activity or an EMP attack on transmission
system protections. As described in section II.A of this document, this
issue has been addressed through the implementation of the National
Space Weather Action Plan, improved grid reliability standards, and
other activities required by the 2019 Executive Order 13865,
``Coordinating National Resilience to Electromagnetic Pulses,'' as well
as close coordination between the utilities, grid operators, and the
SWPC.
Additionally, several commenters were concerned with the safety of
SFPs and potential risks from fires, malicious attacks, and the
compromise of structural integrity. These comments did not introduce
any new information that has not been previously considered and
addressed by the NRC. The NRC has a long history of evaluating SFP
safety and security and has taken action to enhance safety and
security, when necessary. The NRC's responses to public comments on the
MBDBE proposed rule, dated July 31, 2019, include a description of some
of the more important NRC actions involving SFPs.
Public comment submissions also echoed the concern of the
petitioner that emergency systems need to be able to run without human
intervention for up to 2 years and suggested that operators may be
unavailable to reach the site to perform their duties. As discussed in
part A of this section, the aspect of the PRM regarding licensees'
capability to provide continual power for active cooling and/or water
makeup of SFPs has been addressed. In addition, experience with past
natural disasters and emergency events has shown that the NRC and
licensees can respond to emergency situations affecting the ability of
operators to perform their duties. For example, during the COVID-19
public health emergency, licensees were restricted in their ability to
maintain an appropriate workforce to meet the NRC's minimum reactor
operator staffing requirements. Despite these personnel challenges,
public health and safety were maintained during continuous nuclear
power plant operations. Therefore, the NRC has reasonable assurance
that long-term disruptions to emergency systems will not occur and that
operators will be able to perform their duties.
Over two-thirds of the public comment submissions for PRM-50-96
were partially addressed by the MBDBE final rule as they included
concerns about the sufficiency of long-term cooling and offsite power
availability. The requirements in Sec. 50.155(b)(1) and (c) address,
in part, the issues raised by the comments because these regulations
require licensees to establish offsite assistance to support
maintenance of the key functions, including both reactor and SFP
cooling, following an extended loss of alternating current power.
Additionally, the NRC received multiple public comment submissions
on the MBDBE proposed rule that concerned the effects of geomagnetic
disturbances, and the Commission deferred these comments to the
resolution of the outstanding issues in PRM-50-96. Although the MBDBE
rule requires mitigation strategies that could be initially deployed
and used to address the effects of geomagnetic disturbances if such
disturbances lead to adverse impacts on the transmission system and an
associated loss of offsite power, the MBDBE rule's regulatory scope
does not address the issue of geomagnetic disturbances in its entirety.
The deferred comments were concerned about the long-term failure of
critical
[[Page 19250]]
grid infrastructure and SFP cooling equipment and adequate resupply of
licensees by outside resources. Section II.A of this document explains
how these concerns have been addressed.
III. Availability of Documents
The documents identified in the following table are available to
interested persons through one or more of the following methods, as
indicated.
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ADAMS Accession No./web
Document link/Federal Register
citation
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PRM-50-96--Foundation for Resilient ML110750145.
Societies Petition to Amend 10 CFR 50 ``To
Assure Long-Term Cooling and Unattended
Water Makeup of Spent Fuel Pools,'' March
14, 2011.
Federal Register Notice: Petition for 76 FR 26223.
rulemaking; receipt and request for
comment; PRM-50-96: ``Petition for
Rulemaking Submitted by Thomas Popik,''
May 6, 2011.
Federal Register Notice: Petition for 77 FR 74788.
rulemaking; consideration in the
rulemaking process; PRM-50-96: ``Long-Term
Cooling and Unattended Water Makeup of
Spent Fuel Pools,'' December 18, 2012.
Federal Register Notice: Final Rule, 84 FR 39684.
``Mitigation of Beyond-Design-Basis
Events,'' August 9, 2019.
NOAA SWPC Models........................... https://www.swpc.noaa.gov/models models.
NOAA SWPC Press Release, ``New Space https://www.swpc.noaa.gov/
Weather Model, the Geoelectric Field news/new-space-weather-
Model, Announced Today,'' June 27, 2017. model-geoelectric-field-
model-announced-today.
Cooperative Institute for Research in https://cires.colorado.edu/
Environmental Sciences (CIRES) Press recognition/noaa-and-cires-
Release, ``A NOAA and CIRES team, team-breakthrough-space-
Breakthrough Space Weather Model,'' 2022. weather-model.
EPRI Report ``Magnetohydrodynamic https://www.epri.com/
Electromagnetic Pulse Assessment of the research/products/
Continental U.S. Electric Grid: Voltage 3002011969.
Stability Analysis,'' December 20, 2017.
NERC TPL-007-4, ``Transmission System https://www.nerc.com/pa/
Planned Performance for Geomagnetic Stand/
Disturbance Events''. Reliability%20Standards/
tpl-007-4.PDF.
Presidential Document: Executive Order 81 FR 71573.
13744, ``Coordinating Efforts to Prepare
the Nation for Space Weather Events,''
October 18, 2016.
National Science and Technology Council https://
Report, ``Implementation Plan of the bidenwhitehouse.archives.g
National Space Weather Strategy and Action ov/ostp/news-updates/2023/
Plan,'' December 2023. 12/20/implementation-plan-
of-the-national-space-
weather-strategy-and-
action-plan/.
Regulatory Guide 1.137, Revision 2, ``Fuel ML12300A122.
Oil Systems for Emergency Power
Supplies,'' June 2013.
Presidential Document: Executive Order 84 FR 12041.
13865, ``Coordinating National Resilience
to Electromagnetic Pulses,'' March 29,
2019.
Federal Emergency Management Agency, https://www.fema.gov/sites/
``National Response Framework,'' October default/files/documents/
28, 2019. NRF_FINALApproved_2011028.
pdf.
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IV. Conclusion
The NRC is denying the aspects of PRM-50-96 that were not fully
addressed by the MBDBE final rule and is discontinuing the ``Long-Term
Cooling and Unattended Water Makeup of Spent Fuel Pools'' rulemaking
for the reasons discussed in this document. If the NRC decides to
pursue similar or related rulemaking activities in the future, it will
inform the public through new rulemaking entries in the Unified Agenda.
Dated: May 1, 2025.
For the Nuclear Regulatory Commission.
Carrie Safford,
Secretary of the Commission.
[FR Doc. 2025-07899 Filed 5-6-25; 8:45 am]
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