[Federal Register Volume 88, Number 172 (Thursday, September 7, 2023)]
[Notices]
[Pages 61621-61625]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-19297]
[[Page 61621]]
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NUCLEAR REGULATORY COMMISSION
[Docket Nos. 50-266 and 50-301; NRC-2023-0132]
NextEra Energy Point Beach, LLC; Point Beach Nuclear Plant, Units
1 and 2
AGENCY: Nuclear Regulatory Commission.
ACTION: Exemption; issuance.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing an
exemption from certain portions of the acceptance criteria for
emergency core cooling systems to allow the use of a risk-informed
analysis to evaluate the effects of debris in containment following a
loss-of-coolant accident for the Point Beach Nuclear Plant, Units 1 and
2 (Point Beach) located in Manitowoc County, Wisconsin. The exemption
is in response to a request dated July 29, 2022, as supplemented by
letter dated June 9, 2023, from NextEra Energy Point Beach, LLC
(NextEra, the licensee).
DATES: The exemption was issued on August 28, 2023.
ADDRESSES: Please refer to Docket ID NRC-2023-0132 when contacting the
NRC about the availability of information regarding this document. You
may obtain publicly available information related to this document
using any of the following methods:
Federal Rulemaking website: Go to https://www.regulations.gov and search for Docket ID NRC-2023-0132. Address
questions about Docket IDs in Regulations.gov to Stacy Schumann;
telephone: 301-415-0624; email: [email protected]. For technical
questions, contact the individual 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 of this document.
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 (ET), Monday through Friday, except
Federal holidays.
FOR FURTHER INFORMATION CONTACT: Scott P. Wall, Office of Nuclear
Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001; telephone: 301-415-2855; email: [email protected].
SUPPLEMENTARY INFORMATION: The text of the exemption is attached.
Dated: September 1, 2023.
For the Nuclear Regulatory Commission.
Scott P. Wall,
Senior Project Manager, Plant Licensing Branch III, Division of
Operating Reactor Licensing, Office of Nuclear Reactor Regulation.
Attachment--Exemption
Nuclear Regulatory Commission
Docket Nos. 50-266 and 50-301
NextEra Energy Point Beach, LLC
Point Beach Nuclear Plant, Units 1 and 2
Exemption
I. Background
NextEra Energy Point Beach, LLC (NextEra, the licensee) is the
holder of Renewed Facility Operating License Nos. DPR-24 and DPR-27,
which authorize operation of the Point Beach Nuclear Plant, Units 1 and
2 (Point Beach), respectively. The licenses provide, among other
things, that the facility is subject to all rules, regulations, and
orders of the U.S. Nuclear Regulatory Commission (NRC, the Commission)
now or hereafter in effect. The facility consists of two pressurized-
water reactors (PWRs) located in Manitowoc County, Wisconsin.
In 1996, the NRC identified Generic Safety Issue (GSI)-191,
``Assessment of Debris Accumulation on PWR Sump Performance,''
associated with the effects of debris accumulation on PWR sump
performance during design-basis accidents. As part of the actions to
resolve GSI-191, the NRC issued Generic Letter (GL) 2004-02,
``Potential Impact of Debris Blockage on Emergency Recirculation during
Design Basis Accidents at Pressurized-Water Reactors,'' dated September
13, 2004 (Agencywide Documents Access and Management System (ADAMS)
Accession No. ML042360586), to holders of operating licenses for PWRs.
In GL 2004-02, the NRC staff requested that these licensees perform an
evaluation of their emergency core cooling system (ECCS) and
containment spray system (CSS) recirculation functions considering the
potential for debris-laden coolant to be circulated by the ECCS and the
CSS after a loss-of-coolant accident (LOCA) or high-energy line break
inside containment and, if appropriate, take additional actions to
ensure system function. GL 2004-02 required that these licensees
provide a written response to the NRC, pursuant to title 10 of the Code
of Federal Regulations (10 CFR) section 50.54(f), describing the
results of their evaluation and any modifications made, or planned, to
ensure ECCS and CSS system function during recirculation following a
design-basis event, or any alternate action proposed, and the basis for
its acceptability.
II. Request/Action
By application dated July 29, 2022 (ML22210A086), as supplemented
by letter dated June 9, 2023 (ML23163A022), the licensee, pursuant to
10 CFR 50.12, ``Specific exemptions,'' requested, in part, an exemption
from certain requirements of 10 CFR 50.46, ``Acceptance criteria for
emergency core cooling systems for light-water nuclear power
reactors,'' to allow the use of a risk-informed methodology instead of
the traditional deterministic methodology to resolve the concerns
associated with GSI-191 and to respond to GL 2004-02 for Point Beach.
III. Discussion
Pursuant to 10 CFR 50.12, the Commission may, upon application by
any interested person or upon its own initiative, grant exemptions from
the requirements of 10 CFR part 50 when (1) the exemptions are
authorized by law, will not present an undue risk to the public health
and safety, and are consistent with the common defense and security and
(2) special circumstances are present. Under 10 CFR 50.12(a)(2)(ii),
special circumstances are present when ``[a]pplication of the
regulation in the particular circumstances would not serve the
underlying purpose of the rule or is not necessary to achieve the
underlying purpose of the rule.'' Under 10 CFR 50.12(a)(2)(iii),
special circumstances are present when ``[c]ompliance would result in
undue hardship or other costs that are significantly in excess of those
contemplated when the regulation was adopted, or that are significantly
in excess of those incurred by others similarly situated.''
[[Page 61622]]
NextEra submitted a request for exemption under 10 CFR 50.12 for
Point Beach from certain requirements of 10 CFR 50.46(a)(1) as it
relates to using specific deterministic methodology to evaluate the
effects of debris generated from breaks on long-term core cooling. The
licensee stated that the scope of the requested exemption applies to
all debris effects addressed in the risk-informed element of the Point
Beach methodology described in NextEra's July 29, 2022, submittal
responding to GL 2004-02. NextEra stated that the addressed debris
effects are those associated with breaks that potentially generate and
transport debris amounts that exceed the Point Beach-specific tested/
analyzed debris limits.
The licensee is requesting an exemption related to these breaks to
allow evaluation of the debris effects using a risk-informed
methodology in lieu of a deterministic methodology. The licensee stated
that the key elements of the exemption request are that (1) the
exemption will apply only to the effects of debris as described in
Enclosure 4 of the submittal dated July 29, 2022, and (2) the exemption
will apply to any breaks that can generate and transport debris that is
not bounded by Point Beach-specific tested/analyzed debris limits,
provided that the change in core damage frequency ([Delta]CDF) and the
change in large early release frequency ([Delta]LERF) remain within the
acceptance guidelines identified as Region III of Regulatory Guide (RG)
1.174, ``An Approach for Using Probabilistic Risk Assessment in Risk-
Informed Decisions on Plant-Specific Changes to the Licensing Basis,''
Revision 3, dated January 2018 (ML17317A256).
The NRC staff performed an integrated review of the risk-informed
approach proposed to be used in lieu of a deterministic methodology by
the requested exemption, considering the five key principles of risk-
informed decision-making set forth in RG 1.174. The five key principles
are: (1) the proposed change meets the current regulations unless it is
explicitly related to a requested exemption; (2) the proposed change is
consistent with the defense-in-depth (DID) philosophy; (3) the proposed
change maintains sufficient safety margins; (4) when proposed changes
result in an increase in risk, the increases should be small and
consistent with the intent of the Commission's policy statement on
safety goals for the operations of nuclear power plants (51 FR 30028);
and (5) the impact of the proposed change should be monitored using
performance measurement strategies.
The NRC staff finds that the proposed risk-informed approach meets
the five key principles in RG 1.174. The proposed risk-informed
approach is consistent with the DID philosophy, maintains sufficient
safety margins, and is monitored using performance measurement
strategies. The proposed risk-informed approach also explicitly relates
to a requested exemption. Finally, the Point Beach risk evaluation
results show that the risk associated with post-accident debris effects
is within the RG 1.174 Region Ill acceptance guidelines as a ``very
small change'' and, therefore, is consistent with the intent of the
Commission's policy statement on safety goals for the operations of
nuclear power plants.
A. The Exemption Is Authorized by Law
The exemption would allow the use of a risk-informed methodology to
show compliance with 10 CFR 50.46(a)(1), when considering debris in
containment generated and transported by those breaks that exceed the
plant-specific tested/analyzed debris limits. As stated above, 10 CFR
50.12 allows the NRC to grant exemptions from the requirements of 10
CFR part 50, including 10 CFR 50.46(a)(1), when the exemptions are
authorized by law. The NRC staff has determined, as explained below,
that granting the exemption will not result in a violation of the
Atomic Energy Act of 1954, as amended, or the Commission's regulations.
Therefore, the exemption is authorized by law.
B. The Exemption Presents No Undue Risk to Public Health and Safety
The provisions of 10 CFR 50.46 establish criteria for the ECCS
performance. The licensee submitted a request for an exemption under 10
CFR 50.12 for Point Beach from certain requirements of 10 CFR
50.46(a)(1) as it relates to using a specific deterministic methodology
to evaluate the effects of debris generated from breaks on long-term
core cooling. The licensee justified its requested exemption by stating
that it is consistent with the purpose of the requirements in that the
use of the proposed risk-informed approach would account for the
effects of debris on the ECCS cooling performance and would support a
high probability of successful ECCS performance, based on the risk
results meeting the acceptance guidelines of RG 1.174. Additionally,
the licensee stated that the Point Beach risk quantification showed
that the [Delta]CDF and [Delta]LERF are below the threshold for RG
1.174 Region Ill ``very small changes.'' The licensee stated that the
proposed risk-informed approach would provide an equivalent level of
assurance for sump performance as 10 CFR 50.46 without incurring
significant cost and occupational dose associated with removing,
replacing, or reinforcing insulation in containment.
The NRC staff finds that the risk associated with the requested
exemption is consistent with the guidance in RG 1.174 for the use of
probabilistic risk assessment and with the Commission's policy
statement on safety goals for the operations of nuclear power plants;
therefore, the requested exemption presents no undue risk to the public
health and safety.
C. The Exemption Is Consistent With the Common Defense and Security
The requested exemption would allow the licensee to use a risk-
informed methodology to resolve a generic safety concern for PWRs
associated with potential clogging of the ECCS and CSS strainers during
certain design-basis events. The change is adequately controlled by
safety acceptance criteria and technical specification requirements and
is not related to security issues. Because the common defense and
security is not impacted by the exemption, the exemption is consistent
with the common defense and security.
D. Special Circumstances
The requested exemption from 10 CFR 50.46(a)(1) would allow the
licensee to use a risk-informed methodology in lieu of a deterministic
methodology to show conformance with the ECCS and CSS performance
criteria accounting for debris in containment for LOCAs. In its
request, the licensee cited the special circumstances criteria of 10
CFR 50.12(a)(2)(ii) and (iii) and stated that application of the
regulation in the particular circumstances would not serve the
underlying purpose of the rule or is not necessary to achieve the
underlying purpose of the rule and that compliance would result in
undue hardship or other costs that are significantly in excess of those
contemplated when the regulation was adopted, or that are significantly
in excess of those incurred by others similarly situated.
The licensee stated that the intent of 10 CFR 50.46(a)(1) is to
ensure that ECCS cooling performance design requirements imposed by 10
CFR 50.46 are determined by a rigorous method that provides a high
level of confidence in ECCS performance. The licensee stated that its
proposed risk-informed approach accounts for the effects of debris on
the ECCS cooling performance and supports a high probability of
successful ECCS performance based on
[[Page 61623]]
the risk results meeting the acceptance guidelines of RG 1.174.
The licensee also stated that in order to meet a deterministic
threshold value for sump debris loads, the debris sources in
containment would need to be significantly reduced. The licensee stated
that the amount of radiological exposure received during the removal
and/or modification of insulation from the Point Beach containments is
dependent on the scope of the changes. The licensee estimated
generically that the expected total dose for replacing calcium silicate
and asbestos calcium silicate insulation in the Point Beach containment
would be approximately 900 roentgen equivalent man (rem) for both units
(total two-unit dose). An additional dose of 200 rem was estimated for
replacing the mineral wool insulation on the resistance temperature
detector lines.
Based on the above, the licensee concluded that the special
circumstances described in 10 CFR 50.12(a)(2)(ii) and (iii) are present
with respect to its requested exemption.
The NRC staff summarized its evaluation of the proposed risk-
informed approach related to the exemption request in a safety
evaluation (ML23208A095). Since 10 CFR 50.46(a)(1) requires a
deterministic approach, an exemption is an appropriate means to grant
the licensee relief to use an alternative, risk-informed approach. The
underlying purpose of the regulation is to protect the public health
and safety in the event of a LOCA by establishing criteria for the
ECCS. In its safety evaluation, the NRC staff concluded, in part, that
the licensee adequately demonstrated that the change in risk
attributable to debris in postulated LOCAs is very small. The NRC staff
also concluded that the licensee's proposal for demonstrating
compliance with the ECCS and the CSS performance requirements meets the
risk acceptance guidelines in RG 1.174, because the approach is related
to a permissible exemption request, is consistent with DID philosophy,
maintains sufficient safety margins, results in an increase in risk
that is small and consistent with the intent of the Commission's policy
statement on safety goals for the operations of nuclear power plants,
and is monitored by the licensee using performance measurement
strategies. Therefore, the NRC staff finds that the licensee's use of
the proposed risk-informed approach to consider the impacts of debris
meets the underlying intent of 10 CFR 50.46 to ensure that a licensee
demonstrates that the ECCS and the CSS will provide adequate cooling
for the reactor core and containment following postulated design-basis
accidents.
The NRC staff also finds that the licensee demonstrated that using
the required deterministic approach as opposed to the proposed risk-
informed approach would result in undue hardship or other costs that
are significantly in excess of those contemplated when the regulation
was adopted, or that are significantly in excess of those incurred by
others similarly situated.
Based on the above, the special circumstances described in 10 CFR
50.12(a)(2)(ii) and (iii) are present for the requested exemption.
E. Environmental Considerations
The NRC staff determined that the exemption discussed herein meets
the eligibility criteria for categorical exclusion set forth in 10 CFR
51.22(c)(9) because it is related to a requirement concerning the
installation or use of facility components located within the
restricted area, as defined in 10 CFR part 20, and the granting of the
exemption involves: (i) no significant hazards consideration, (ii) no
significant change in the types or significant increase in the amounts
of any effluents that may be released offsite, and (iii) no significant
increase in individual or cumulative occupational radiation exposure.
Therefore, in accordance with 10 CFR 51.22(b), no environmental impact
statement or environmental assessment need to be prepared in connection
with the issuance of the exemption. The basis for this NRC staff
determination is discussed as follows with an evaluation against each
of the requirements in 10 CFR 51.22(c)(9).
Requirements in 10 CFR 51.22(c)(9)(i)
The NRC staff evaluated the issue of no significant hazards
consideration, using the standards described in 10 CFR 50.92(c), as
presented below:
1. Does the requested exemption involve a significant increase in
the probability or consequences of an accident previously evaluated?
Response: No.
The proposed change that would be implemented as a result of the
exemption is a methodology change for assessment of debris effects that
adds the results of a risk-informed evaluation to the Point Beach
licensing basis. This is a viable approach for the resolution of GL
2004-02 per SECY-12-0093, ``Closure Options for Generic Safety Issue--
191, Assessment of Debris Accumulation on Pressurized-Water Reactor
Sump Performance,'' dated June 9, 2012 (ML121310648). The analysis that
supports the methodology change concludes that the functionality of the
ECCS and CSS during design-basis accidents is confirmed by the very
small risk increase due to strainer failures associated with the debris
effects, supported by the fact that the safety margin and DID are
maintained with high probability. The proposed change addresses
mitigation of LOCAs and has no effect on the probability of the
occurrence of a LOCA. The proposed change does not implement any
changes in the facility or plant operation that could lead to a
different kind of accident. The containment sump is not an initiator of
any accident previously evaluated. The containment sump is a passive
component, and the proposed change does not increase the likelihood of
a malfunction of the sump. The design and the capability of the
containment sump assumed in the accident analysis are not changed. As a
result, the probability of an accident is unaffected by the proposed
change.
The proposed change does not involve a significant increase in the
consequences of an accident previously evaluated. The proposed change
confirms that required structures, systems, and components (SSCs)
supported by the containment sumps will perform their safety functions
with a high probability, as required, and does not alter or prevent the
ability of SSCs to perform their intended function to mitigate the
consequences of an accident previously evaluated within the acceptance
limits. The proposed change has no impact on existing barriers that
prevent the release of radioactivity. The safety analysis acceptance
criteria in the Point Beach Final Safety Analysis Report (FSAR)
continue to be met for the proposed change.
Therefore, the requested exemption does not involve a significant
increase in the probability or consequences of an accident previously
evaluated.
2. Does the requested exemption create the possibility of a new or
different kind of accident from any accident previously evaluated?
Response: No.
The proposed change that would be implemented as a result of the
exemption is a methodology change for assessment of debris effects that
adds the results of a risk-informed evaluation to the Point Beach
licensing basis. The proposed change does not install or remove any
plant equipment, or alter the design, physical configuration, or mode
of operation of any plant SSCs. The proposed change does not introduce
any new failure mechanisms or malfunctions that can initiate an
accident. No new credible accident is
[[Page 61624]]
created that is not encompassed by the existing accident analyses that
assume the functioning of the containment sump.
Therefore, the requested exemption does not create the possibility
of a new or different kind of accident from any previously evaluated.
3. Does the requested exemption involve a significant reduction in
a margin of safety?
Response: No.
The proposed change that would be implemented as a result of the
exemption is a methodology change for assessment of debris effects that
adds the results of a risk-informed evaluation to the Point Beach
licensing basis. The effects from a full spectrum of LOCAs and
secondary side breaks inside containment, including double-ended
guillotine breaks, are analyzed. Appropriate redundancy and
consideration of loss of offsite power and worst-case single failure
are retained, such that DID is maintained.
Application of the risk-informed methodology showed that the
increase in risk from the contribution of debris effects is very small
as defined by RG 1.174 and that there is adequate DID and safety
margin, which are extensively evaluated in Enclosure 5 of the July 29,
2022, submittal and which evaluation is found to be acceptable in the
related NRC staff safety evaluation. This evaluation showed that there
is substantial DID and safety margin that provide a high level of
confidence that the calculated risk for the effects of debris is
conservative and that the actual risk is likely much lower.
Consequently, the licensee determined that the risk-informed method
demonstrates that the containment sumps will continue to support the
ability of safety-related components to perform their design functions
when the effects of debris are considered. This risk-informed approach
was identified as viable for the response to GL 2004-02 per SECY-12-
0093. The proposed change does not alter the manner in which safety
limits are determined or the acceptance criteria associated with a
safety limit. The proposed change does not implement any changes to
plant operation and does not affect SSCs that respond to safely shut
down the plant and to maintain the plant in a safe shutdown condition.
The proposed change does not significantly affect the existing safety
margins in the barriers to the release of radioactivity. There are no
changes to any of the safety analyses in the FSAR.
Therefore, the requested exemption does not involve a significant
reduction in a margin of safety.
Based on the above, the NRC staff concludes that the requested
exemption involves no significant hazards consideration and, therefore,
satisfies 10 CFR 51.22(c)(9)(i)).
Requirements in 10 CFR 51.22(c)(9)(ii)
No physical modifications or changes to operating requirements are
proposed for the facility as part of the requested exemption, including
changes to any SSCs relied upon to mitigate the consequences of a LOCA.
No changes are made to the safety analyses in the FSAR. Approval of the
exemption will require the calculated risk associated with post-
accident debris effects to meet the Region III acceptance guidelines in
RG 1.174, thereby maintaining the public health and safety. As such,
the NRC staff concludes that the requested exemption does not involve
significant change in the types or significant increase in the amounts
of any effluents that may be released offsite. Therefore, the requested
exemption satisfies 10 CFR 51.22(c)(9)(ii).
Requirements in 10 CFR 51.22(c)(9)(iii)
No new operator actions are implemented that could affect
occupational radiation exposure. No physical modifications or changes
to operating requirements are proposed for the facility as part of the
requested exemption, including changes to any SSCs relied upon to
mitigate the consequences of a LOCA. No changes are made to the safety
analyses in the FSAR. As such, the NRC staff concludes that the
requested exemption does not involve significant increase in individual
or cumulative occupational radiation exposure. Therefore, the requested
exemption satisfies 10 CFR 51.22(c)(9)(iii).
Conclusion
Based on the above, the NRC staff concludes that the requested
exemption meets the eligibility criteria for the categorical exclusion
set forth in 10 CFR 51.22(c)(9). Therefore, in accordance with 10 CFR
51.22(b), no environmental impact statement or environmental assessment
need be prepared in connection with the issuance of the exemption.
IV. Conclusions
Accordingly, the Commission has determined that, pursuant to 10 CFR
50.12, the exemption is authorized by law, will not present an undue
risk to the public health and safety, and is consistent with the common
defense and security. Also, special circumstances are present.
Therefore, the Commission hereby grants NextEra's request for an
exemption from 10 CFR 50.46(a)(1) to allow the use of a risk-informed
methodology in lieu of a deterministic methodology to show conformance
with the ECCS and CSS performance criteria accounting for debris in
containment for those breaks that exceed the Point Beach-specific
tested/analyzed debris limits.
This exemption is effective upon issuance.
V. Availability of Documents
The documents identified in the following table are related to the
requested exemption and available to interested persons through the
NRC's ADAMS at https://adams.nrc.gov/wba/.
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Document ADAMS Accession No.
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NextEra letter, ``Exemption Request, License ML22210A086.
Amendment Request and Revised Response in
Support of a Risk-informed Resolution of
Generic Letter 2004-02'' (L-2022-121), dated
July 29, 2022.
NextEra letter, ``Response to Request for ML23163A022.
Additional Information (RAI) Regarding
Exemption Request, License Amendment Request
and Revised Response in Support of a Risk-
Informed Resolution of Generic Letter 2004-02''
(L-2023-075), dated June 9, 2023.
NRC Generic Letter 2004-02, ``Potential Impact ML042360586.
of Debris Blockage on Emergency Recirculation
During Design Basis Accidents at Pressurized-
Water Reactors,'' dated September 13, 2004.
Regulatory Guide 1.174, Revision 3, ``An ML17317A256.
Approach for Using Probabilistic Risk
Assessment in Risk-Informed Decisions on Plant-
Specific Changes to the Licensing Basis,''
dated January 2018.
NRC letter, ``Point Beach Nuclear Plant, Units 1 ML23208A095.
and 2--Issuance of Amendment Nos. 273 and 275
Regarding Revising Licensing Basis to Address
Generic Safety Issue 191 and to Respond to
Generic Letter 2004-02 Using a Risk-Informed
Approach,'' dated August 28, 2023.
[[Page 61625]]
NextEra letter, ``Response to Generic Letter ML073230345.
2004-02, Potential Impact of Debris Blockage on
Emergency Recirculation During Design Basis
Accidents at Pressurized-Water Reactors'' (NRC
2007-0085), dated November 16, 2007.
NextEra letter, ``Updated Final Response to NRC ML17363A253.
Generic Letter 2004-02'' (NRC 2017-0045),
December 29, 2017.
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Dated: August 28, 2023.
For the Nuclear Regulatory Commission.
Victor G. Cusumano,
Acting Deputy Director, Division of Operating Reactor Licensing, Office
of Nuclear Reactor Regulation.
[FR Doc. 2023-19297 Filed 9-6-23; 8:45 am]
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