[Federal Register Volume 90, Number 142 (Monday, July 28, 2025)]
[Proposed Rules]
[Pages 35441-35445]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-14146]
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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. 90, No. 142 / Monday, July 28, 2025 /
Proposed Rules
[[Page 35441]]
NUCLEAR REGULATORY COMMISSION
10 CFR Part 50
[Docket No. PRM-50-121; NRC-2020-0055]
Voluntary Adoption of Revised Design Basis Accident Dose Criteria
AGENCY: Nuclear Regulatory Commission.
ACTION: Petition for rulemaking; denial.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is denying a
petition for rulemaking, dated November 23, 2019, submitted by John G.
Parillo. The petition requested that the NRC develop a rule that would
allow nuclear power plant licensees to voluntarily adopt a revised
accident dose acceptance criteria for the control room, exclusion area
boundary, and the low population zone outer boundary. The petition
further requested revisions to clarify footnotes discussing these dose
acceptance criteria in the applicable regulations. The NRC docketed the
petition on February 19, 2020, and assigned it Docket No. PRM-50-121.
The NRC is denying the petition because the information presented does
not support rulemaking and the proposed changes are not necessary to
provide reasonable assurance of adequate protection of public health
and safety.
DATES: The docket for the petition for rulemaking PRM-50-121 is closed
on July 28, 2025.
ADDRESSES: Please refer to Docket ID NRC-2020-0055 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-2020-0055. Address
questions about NRC dockets to Helen Chang; telephone: 301-415-3228;
email: [email protected]. For technical questions, contact the
persons 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: You may examine and purchase copies of public
documents by appointment at the NRC's PDR, Room P1 B35, One White Flint
North, 11555 Rockville Pike, Rockville, Maryland 20852. 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: Elijah Dickson, Office of Nuclear
Reactor Regulation, telephone: 301-415-7647, email:
[email protected] or Tyler Hammock, Office of Nuclear Material
Safety and Safeguards, telephone: 301-415-1381, email:
[email protected]. Both are employees of the U.S. Nuclear
Regulatory Commission, Washington, DC 20555-0001.
SUPPLEMENTARY INFORMATION:
I. The Petition
Section 2.802 of title 10 of the Code of Federal Regulations (10
CFR), ``Petition for rulemaking--requirements for filing,'' provides an
opportunity for any interested person to petition the Commission to
issue, amend, or rescind any regulation. On November 23, 2019, the NRC
received a petition for rulemaking (PRM) from John G. Parillo.
The petition requested that the NRC develop a rule allowing
licensees to voluntarily adopt a revised dose acceptance criteria of 10
rem total effective dose equivalent (TEDE) for the control room, the
exclusion area boundary, and the low population zone. The petitioner
identified concerns with the current acceptance (i.e., dose) criteria
in 10 CFR part 100, ``Reactor Site Criteria,'' Sec. 100.11,
``Determination of exclusion area, low population zone, and population
center distance,'' its basis document, Technical Information Document
(TID)-14844, ``Calculation of Distance Factors for Power and Test
Reactor Sites,'' United States Atomic Energy Commission, March 23,
1962, and the alternate accident source term requirements in 10 CFR
part 50, ``Domestic Licensing of Production and Utilization
Facilities,'' Sec. 50.67, ``Accident source term.'' Additionally, this
petition examined the objectives of the control room design criterion
in 10 CFR part 50, appendix A, ``General Design Criteria for Nuclear
Power Plants,'' criterion 19, ``Control Room,'' and the relationship
between the control room design criterion and the reactor site
criteria. The petitioner also identified concerns with the translation
of the Sec. 100.11 dose criteria (25 rem whole body and 300 rem
thyroid) into the single 25 rem dose criterion used in other
regulations, including requirements applicable to: (1) construction
permit applicants under Sec. 50.34(a); (2) applicants under 10 CFR
part 52, ``Licenses, Certification, and Approvals for Nuclear Power
Plants;'' and (3) licensees of operating nuclear power plants
originally licensed prior to January 10, 1997, who seek to revise their
accident source term under Sec. 50.67. With regard to these
regulations, applicants must demonstrate that the following
radiological acceptance criteria are met: (1) an individual located on
any point on the boundary of the exclusion area for any 2-hour period
following the onset of postulated fission product release would not
receive a radiation dose in excess of 0.25 sievert (Sv) (25 rem) TEDE;
(2) an individual located at any point on the outer boundary of the low
population zone, who is exposed to the radioactive cloud resulting from
the postulated fission product release (during the entire period of its
passage), would not receive a radiation dose in excess of 0.25 Sv (25
rem) TEDE; and (3) adequate radiation protection is provided to permit
access to, and occupancy of, the control room under accident conditions
without personnel receiving radiation exposures in excess of 0.05 Sv (5
rem) TEDE for the duration of the accident.
[[Page 35442]]
For the purposes of this document, ``siting criteria'' refers to
the 0.25 Sv (25 rem) exclusion area boundary and low population zone
TEDE criteria, and the ``control room design criterion'' refers to the
0.05 Sv (5 rem) control room TEDE criterion.
The NRC identified three unique categories of petitioned changes
within PRM-50-121: (1) voluntary rule development; (2) conforming
changes to Regulatory Guide (RG) 1.183, ``Alternative Radiological
Source Terms for Evaluating Design Basis Accidents at Nuclear Power
Reactors'' (ML003716792); and (3) other petitioned changes, which
include proposed changes to footnotes.
Voluntary Rule Development
The petition requested that the NRC develop a rule that would allow
licensees to voluntarily adopt a revised accident dose acceptance
criterion of 0.1 Sv (10 rem) TEDE for the three criteria in Sec.
50.67(b)(2). The petition stated that the voluntary rule would be
reflective of modern health physics recommendations and modern plant
designs. The petition stated that NRC's design basis accident (DBA)
dose criteria and the resulting design of accident mitigation systems
could be perceived to emphasize protection of the control room operator
over protection of the public. Further, the petition stated that the
proposed change would provide a better balance between protection of
the control room operators and the protection of the public. The
petition also noted that the control room design criterion has proven
to be challenging to demonstrate because most nuclear power plants have
minimal margin to the 0.05 Sv (5 rem) TEDE regulatory criterion
contained in Sec. 50.67(b)(2)(iii). The petition claimed that a
uniform criterion of 0.1 Sv (10 rem) TEDE in a new Sec. 50.67a would
relieve the current regulatory burden associated with meeting the
current control room design criterion for current operating nuclear
power plants. Therefore, the petition also recommended conforming
changes to General Design Criterion (GDC) 19 of appendix A to 10 CFR
part 50 to permit the use of a 0.1 Sv (10 rem) TEDE control room design
criterion if a 0.1 Sv (10 rem) TEDE criterion for the alternate source-
term siting criterion was voluntarily adopted.
Proposed Changes to Regulatory Guide 1.183
The petition suggested that RG 1.183 be revised to align with the
regulations in new Sec. 50.67a, as proposed by the petition.
Other Petitioned Changes
The petition proposed several revisions to footnotes to 10 CFR
parts 50, 52, and 100. First, the petition suggested that the NRC
remove references to the National Bureau of Standards (NBS) Handbook
69, ``Maximum Permissible Body Burdens and Maximum Permissible
Concentrations of Radionuclides in Air and in Water for Occupational
Exposure,'' in 10 CFR parts 50, 52, and 100 (i.e., Sec. Sec. 50.34,
52.17, 52.47, 52.79, 52.137, 52.157, and 100.11) based on the
petition's assertion that the NBS Handbook 69 is outdated, conflicts
with 10 CFR part 20, ``Standards for Protection Against Radiation,''
and was only intended to be used for a once-in-a-lifetime accidental or
emergency dose to radiation workers. Second, the petition stated that
there are inconsistencies between the terms ``whole-body dose'' and
``total effective dose equivalent,'' describing the 0.25 Sv (25 rem)
criterion in current regulations in 10 CFR parts 50, 52, and 100
footnotes. Third, the petition suggested revisions to footnotes to 10
CFR parts 50 and 52 to address the relationship between cancer and
radiation exposures. Lastly, the petition noted a grammatical error in
a footnote to Sec. 52.17(a)(1)(ix)(A).
The petition provided a review and analysis of the regulatory
history of each of the criteria and derivations from the previous
whole-body and thyroid criteria to the TEDE criteria (i.e., Sec. 50.34
(61 FR 65157; December 11, 1996)). The petition also provided
references to current health physics guidance recommendations from the
U.S. Environmental Protection Agency (EPA), the International
Commission on Radiological Protection, the International Atomic Energy
Agency, Duke University and Duke Medicine, the Health Physics Society,
the Centers for Disease Control and Prevention, and the NRC. The
petition provided this information to present perspectives between the
selected criteria numerical values to radiation protection
recommendations for emergency workers, the general public, and in-utero
fetal development. Lastly, the petition provided data listing the
current operating reactor fleet analysis of records of licensing-basis
results for each of the three Sec. 50.67(b)(2) criteria. This data
suggests that a number of operating reactors could meet a uniform 10
rem acceptance criteria without making any changes to their analysis of
record radiological consequence analyses and that there is relatively
small margin for most facilities with respect to the current 5 rem
control room design criterion.
II. Public Comments on the Petition
On May 27, 2020 (85 FR 31709), the NRC published a notice of
docketing and request for comment on the PRM in the Federal Register.
The comment period closed on August 10, 2020. All comment submissions
received on this petition are available on https://www.regulations.gov
by searching for Docket ID NRC-2020-0055.
Three comment submissions were received: one from the Nuclear
Energy Institute and two from private citizens. Of the three comment
submissions, one provided general support for the petition, one opposed
the petition, and one submission addressed matters outside the scope of
the petition. A summary of the substantive comments and the NRC's
responses follows. The comments are available as indicated in the
Availability of Documents section of this document.
Comment 1: General Support for Updating the Requirements
The commenter endorsed the use of ``current science based values''
and claimed using data gained over the last 50 years would ``better
protect populations and ease regulatory burden.''
NRC Response
The NRC agrees with the general assertion that regulations should
be based on modern scientific data, operating experience, and analysis;
however, the commenter did not present additional new information to
support the petitioner's proposal that the NRC should amend its
regulations to include a new voluntary rule.
Comment 2: Opposes the Petition Regarding the Need for a Universal
Design and Siting Criteria for the Control Room and the Public
A commenter recommended that the NRC deny the petition and that no
changes be made to specify a uniform value of 0.1 Sv (10 rem) TEDE for
offsite locations and the control room design criteria. The comment
asserted that Sec. 50.67, 10 CFR part 100, GDC-19, 10 CFR part 20, and
by extension, the EPA Protective Action Guidelines (PAGs) all were
established for different purposes and the different requirements work
together to establish a defense-in-depth strategy to protect the
workers and the public. The comment also noted that 10 CFR part 20 dose
limits are not directly applicable in an emergency, and that industry
uses 10 CFR part 20 in conjunction with the EPA's PAGs, in
[[Page 35443]]
responding to a significant plant event. The comment stated that the
petitioner did not provide any supporting evidence that members of the
public perceive the NRC to emphasize protection of the control room
over protection of the public. The comment also stated that the dose
value the NRC has established for control room operators likely
enhances the perception that protection of the public is the primary
concern. Furthermore, the comment indicated that 10 CFR part 100
appears to address this concern by stating that the numbers in the
criteria are not intended to constitute acceptable limits for emergency
doses to the public under accident conditions. Lastly, the commenter
noted that they are unaware of any licensee that would pursue the
voluntary rule and argued that changing nuclear power plant licensing-
basis regulations would place additional burdens on licensees (e.g.,
revising licensing-basis documents, procedures, and training programs,
etc.) with no commensurate improvement in safety.
NRC Response
The NRC agrees the petition should be denied. The NRC agrees that
changes to the regulations to allow licensees to voluntarily adopt a
revised universal acceptance criterion of 0.1 Sv (10 rem) TEDE for the
control room, exclusion area boundary, and the low population zone
outer boundary are not needed.
Further, the NRC agrees with the comment that the acceptance
criteria in 10 CFR parts 50 and 52 are not operational radiation
exposure limits under emergency conditions and recognizes that they are
not the sole regulations applicable during an event. While both the
siting criteria and control room design criterion are computed in terms
of ``dose,'' they are ``figures-of-merit'' used to characterize the
minimum necessary design, fabrication, construction, testing, and
performance requirements for structures, systems, and components. The
numerical selection for both acceptance criteria does not imply
acceptable radiation exposure limits for the public or control room
operators under accident conditions. The acceptance criteria represent
reference values to be used for evaluating plant features and site
characteristics intended to mitigate the radiological consequences of
accidents to provide assurance of low risk to the public under
postulated accidents. The current radiation protection framework,
including the requirements of Sec. 50.67, is coherent and consistent
with international and national radiation protection standards and
recommendations, and continues to provide reasonable assurance of
adequate protection of control room operations and the public.
III. Reasons for Denial
The NRC is denying the petition. This is based on the consideration
of defense-in-depth features of licensed nuclear power plants; the
intended purpose of the 0.25 Sv (25 rem) TEDE siting criteria as a
reference value to evaluate plant design features; modern health
physics knowledge and recommendations; and previous NRC decisions
related to the use of the 0.05 Sv (5 rem) TEDE for the control room
design criteria and 0.25 Sv (25 rem) for the exclusion area boundary
and the low population zone outer boundary.
The petition requested that the NRC develop a new rule (Sec.
50.67a) that would allow licensees to voluntarily adopt revised
accident dose acceptance criteria of 0.1 Sv (10 rem) TEDE for the
control room, exclusion area boundary, and the low population zone
outer boundary. The NRC assessed the selected numerical radiation dose
values referenced in Sec. 50.67(b)(2), considering the modern health
physics recommendations and current plant design information provided
by the petition. The NRC also assessed the criteria based on the
historical evaluation and previous NRC decisions for establishing these
numerical values as representative reference values to be used for
evaluating plant features and site characteristics intended to mitigate
the radiological consequences of accidents to provide reasonable
assurance of adequate protection to the public under postulated
accidents. The evaluation was performed using the criteria provided in
Sec. 2.803, as summarized below. Based on this evaluation, the NRC
concluded that the current regulations provide an adequate level of
protection and rulemaking is not justified.
The siting and control room design criteria in Sec. 50.67(b)(2)
require, in part, that an individual located at any point on the outer
boundary of the low population zone would not receive a radiation dose
in excess of 0.25 Sv (25 rem) TEDE and that personnel in the control
room would not receive radiation exposures in excess of 0.05 Sv (5 rem)
TEDE under accident conditions for the duration of the accident. A
detailed rationale for the use of 0.25 Sv (25 rem) TEDE as an accident
dose criterion and the use of the 2-hour exposure period resulting in
the maximum dose is provided in the final rule on reactor site criteria
for nuclear power plants (61 FR 65157; December 11, 1996). As discussed
in the final rule preamble, the NRC's use of the 0.25 Sv (25 rem) TEDE
value does not mean that this is an acceptable limit for an emergency
dose to the public under accident conditions, but only that it
represents a reference value to be used for evaluating plant features
and site characteristics intended to mitigate the radiological
consequences of accidents in order to provide assurance of low risk to
the public under postulated accidents.
A detailed rationale for the use of the 0.05 Sv (5 rem) TEDE
control room design criterion is provided in the final rule for use of
alternative source terms for operating reactors (64 FR 71990; December
23, 1999). In the preamble for the final alternate source term rule,
the NRC stated that the control room design criteria are not an
acceptable exposure during emergency conditions, or that other
radiation protection standards of 10 CFR part 20, including individual
organ dose limits, do not apply. Instead, the control room design
criterion is provided only to assess the acceptability of design
provisions for protecting control room operators under postulated DBA
conditions. Further, the NRC noted that DBA conditions assumed in these
analyses, although credible, generally do not represent actual accident
sequences but are specified as conservative surrogates to create
bounding conditions for assessing the acceptability of engineered
safety features.
In evaluating PRM-50-121, the NRC also considered the following:
(1) providing a consistent dosimetry methodology with 10 CFR part 20
based on the recommendations contained in International Commission on
Radiological Protection (ICRP) Publication 26, adopted January 17,
1977, and the scientific information contained in ICRP Publication 30;
(2) the basis of the conversion from whole-body and thyroid dose
criteria to the updated TEDE criteria described in the final rule on
reactor site criteria for nuclear power plants in light of more modern
health physics models; (3) the significant margins that exist for
operating plants compared to the latent cancer fatality quantitative
health objective established by the NRC's Safety Goal policy (51 FR
30028; August 21, 1986); and (4) the extensive NRC and industry
licensing experience in applying these dose acceptance criteria and the
inherent conservatisms in their application. In addition, the NRC
considered operational experience with the maximum whole-body dose
received following major core damage accidents at Three Mile Island in
March 1979 and
[[Page 35444]]
the Fukushima Daiichi Nuclear Power Plant in March 2011. As discussed
in the final rule on reactor site criteria, the maximum whole body dose
received by an actual individual during the Three Mile Island accident
was estimated to be about 0.1 rem. The NRC also considered recently
discontinued rulemaking activities (81 FR 95410; December 28, 2016)
associated with revising the radiation protection regulations in 10 CFR
part 20 and 10 CFR part 50, appendix I. This rulemaking activity was
initially intended, in part, to reflect modern health physics
recommendations from the ICRP. In discontinuing this rulemaking
activity, the NRC noted that the current NRC regulatory framework
continues to provide adequate protection of the health and safety of
workers, the public and the environment.
Further, there is additional defense-in-depth in plant designs and
operational programs (e.g., conservative analysis assumptions,
engineered safety features to reduce likelihood of severe accidents,
emergency planning) to minimize risk of public exposure following an
accident. Research studies (e.g., NUREG-1935, ``State-of-the-Art
Reactor Consequence Analysis (SOARCA) Report;'' NUREG-1150, ``Severe
Accident Risks: An Assessment of Five U.S. Nuclear Power Plants;'' and
the ongoing Level 3 probabilistic risk assessment project) and
licensing experience demonstrate that these defense-in-depth measures
maintain an appropriately low risk of radiation exposure to the public.
Regarding the petitioner's observation concerning the footnotes to
10 CFR parts 50, 52, and 100, the NRC agrees with the petitioner that
the references to the NBS Handbook 69 are dated, but they do reflect
the position of the Commission at the time the rule was initiated. This
issue was addressed in Information Notice 84-40, ``Emergency Worker
Doses,'' which states, in part, that ``[n]o endorsement of the NBS
(National Bureau of Standards) Handbook 69 emergency dose guidelines/
recommendations nor application to 10 CFR [part] 20 was ever
intended.'' References to the NBS Handbook 69 in the regulations were
also addressed in the final rule on reactor site criteria for nuclear
power plants (61 FR 65157; December 11, 1996), where the NRC determined
that the ``footnote also clearly states that the Commission's use of
this value does not imply that it considers it to be an acceptable
limit for an emergency dose to the public under accident conditions,
but only that it represents a reference value to be used for evaluating
plant features and site characteristics.'' The footnotes in 10 CFR
parts 50, 52, and 100 only provide explanatory information, do not
provide regulatory requirements, and have not caused regulatory issues
with licensing actions due to the inconsistent language from these
parts (e.g., design certifications and combined license approvals).
Thus, while updating these footnotes may be appropriate to reflect the
current basis for the siting and control room design criteria, the NRC
finds that their clarification does not, on their own, justify
rulemaking.
The petitioner also noted a grammatical error in the footnote to
Sec. 52.17(a)(1)(ix)(A) and recommended that it be revised from ``in
the event of an accidents'' to ``in the event of an accident.'' The NRC
corrected the error in an administrative correction rule published on
November 14, 2022 (87 FR 68028).
The NRC concludes that the concerns presented in the petition do
not reflect immediate safety concerns. In addition, defense-in-depth
features make severe accidents and radiological releases that challenge
the reference dose siting and control room design criteria unlikely.
Further, recent research studies have demonstrated that a significant
margin exists to the NRC's safety goals. Lastly, because the NRC
determined that a new Sec. 50.67a is not needed, conforming changes to
GDC-19 control room design criteria to allow for 10 rem TEDE, and
revisions to RG 1.183 are not necessary. The NRC concludes that the
existing regulations in 10 CFR part 100 and Sec. 50.67(b)(2) continue
to provide reasonable assurance of adequate protection of public health
and safety and that rulemaking is not warranted.
V. 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./ Federal
Document Register Citation
------------------------------------------------------------------------
PRM-50-121--Voluntary Adoption of ML20050M894.
Revised Design Basis Accident
Dose Criteria, dated November 23,
2019.
PRM-50-121: Petition for 85 FR 31709.
rulemaking; notice of docketing,
and request for public comment,
dated May 27, 2020.
Comment from Sandeep Sharma on PRM- ML20154K569.
50-121--Voluntary Adoption of
Revised Design Basis Accident
Dose Criteria; dated June 1, 2020.
Comment from Jerry Kurtz on PRM-50- ML20209A559.
121--Voluntary Adoption of
Revised Design Basis Accident
Dose Criteria; dated July 27,
2020.
Comment from Hilary Lane on behalf ML20233A589.
of Nuclear Energy Institute (NEI)
on PRM-50-121--Voluntary Adoption
of Revised Design Basis Accident
Dose Criteria; August 10, 2020.
``Reactor Site Criteria Including 61 FR 65157.
Seismic and Earthquake
Engineering Criteria for Nuclear
Power Plants,'' Final Rule, dated
December 11, 1996.
``Safety Goals for the Operation 51 FR 30028.
of Nuclear Power Plants,'' Policy
Statement, dated August 21, 1986.
``Reactor Site Criteria Including 59 FR 52255.
Seismic and Earthquake
Engineering Criteria for Nuclear
Power Plants and Proposed Denial
of Petition from Free
Environment, Inc. et al.,''
Proposed Rule, dated October 17,
1994.
``Standards for Protection Against 56 FR 23360.
Radiation.'' Final Rule, dated
May 21, 1991.
Information Notice No. 84-40: ML103420380.
Emergency Worker Doses, dated May
30, 1984.
``Rulemaking Activities Being 81 FR 95410.
Discontinued by the NRC,''
Rulemaking activities;
discontinuation, dated December
28, 2016.
SECY-12-0064--Recommendation for ML121020108 (Package).
Policy and Technical Direction to
Revise Radiation Protection
Regulations and Guidance, dated
April 25, 2012.
National Bureau of Standards ML20206L091.
Handbook 69 ``Maximum Permissible
Body Burdens and Maximum
Permissible Concentrations of
Radionuclides in Air and in Water
for Occupation Exposure,'' dated
August 1963.
``Use of Alternative Source Terms 64 FR 71990.
at Operating Reactors''; Final
Rule, dated December 23, 1999.
``Radiation Protection'', Advance 79 FR 43284.
notice of proposed rulemaking;
request for comments, dated July
25, 2014.
``Miscellaneous Corrections''; 87 FR 68028.
Final Rule, dated November 14,
2022.
NUREG-1150 Vol. 1, ``Severe ML120960691.
Accident Risks: An assessment for
Five U.S. Nuclear Power Plants,''
dated December 1990.
NUREG-1935, ``State-of-the-Art ML12332A057.
Reactor Consequence Analyses
(SOARCA) Report,'' dated November
2012.
[[Page 35445]]
Regulatory Guide 1.183, ML003716792.
``Alternative Radiological Source
Terms for Evaluating Design Basis
Accidents at Nuclear Power
Plants,'' dated July 2000.
SECY-11-0089--Options for ML11090A039 (Package).
Proceeding with Future Level 3
Probabilistic Risk Assessment
Activities, dated July 7, 2011.
------------------------------------------------------------------------
V. Conclusion
For the reasons cited in this document, the NRC is denying PRM-50-
121. The current requirements continue to provide reasonable assurance
of adequate protection of public health and safety and should not be
revised as proposed in the PRM.
Dated: July 24, 2025.
For the Nuclear Regulatory Commission.
Carrie Safford,
Secretary of the Commission.
[FR Doc. 2025-14146 Filed 7-25-25; 8:45 am]
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