Considerations for Estimating Site-Specific Probable Maximum Precipitation at Nuclear Power Plants in the United States of America, 50913-50914 [2021-19636]
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Federal Register / Vol. 86, No. 174 / Monday, September 13, 2021 / Notices
which restricts (with limited
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[FR Doc. 2021–19694 Filed 9–10–21; 8:45 am]
BILLING CODE 9211–03–P
NUCLEAR REGULATORY
COMMISSION
[NRC–2020–0237]
Considerations for Estimating SiteSpecific Probable Maximum
Precipitation at Nuclear Power Plants
in the United States of America
Nuclear Regulatory
Commission.
ACTION: NUREG; issuance.
AGENCY:
The U.S. Nuclear Regulatory
Commission (NRC) is issuing a
knowledge management NUREG,
NUREG/KM–0015, ‘‘Considerations for
Estimating Site-Specific Probable
Maximum Precipitation at Nuclear
Power Plants in the United States of
America.’’ The NRC staff and Oak Ridge
National Laboratory have prepared a
reference document summarizing recent
lessons-learned in connection with a
review of the site-specific probable
maximum precipitation (SSPMP)
estimates used by some nuclear power
plant owners and operators in
connection with a recent re-evaluation
of external flooding at their respective
project sites.
DATES: NUREG/KM–0015 is available on
September 13, 2021.
ADDRESSES: Please refer to Docket ID
NRC–2020–0237 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–2020–0237. Address
lotter on DSK11XQN23PROD with NOTICES1
SUMMARY:
VerDate Sep<11>2014
17:39 Sep 10, 2021
Jkt 253001
questions about Docket IDs in
Regulations.gov to Stacy Schumann;
telephone: 301–415–0624; email:
Stacy.Schumann@nrc.gov. 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, 301–
415–4737, or by email to pdr.resource@
nrc.gov. NUREG/KM–0015,
‘‘Considerations for Estimating SiteSpecific Probable Maximum
Precipitation at Nuclear Power Plants in
the United States of America’’ is
available in ADAMS under Accession
No. ML21245A418.
• Attention: The PDR, where you may
examine, and order copies of public
documents, is currently closed. You
may submit your request to the PDR via
email at pdr.resource@nrc.gov or call
1–800–397–4209 or 301–415–4737,
between 8:00 a.m. and 4:00 p.m. (ET),
Monday through Friday, except Federal
holidays.
FOR FURTHER INFORMATION CONTACT:
Kevin Quinlan, Office of Nuclear
Reactor Regulation, U.S. Nuclear
Regulatory Commission, Washington,
DC 20555–0001; telephone: 301–415–
6809, email: Kevin.Quinlan@nrc.gov.
SUPPLEMENTARY INFORMATION:
I. Background
By letter dated March 12, 2012, the
NRC issued a request for information to
all power reactor licensees and holders
of construction permits in active or
deferred status licensees to reevaluate
seismic and external flooding for their
sites against current Commission
requirements and guidance. This
request was made consistent with
paragraph 50.54(f) of title of the Code of
Federal Regulations (10 CFR),
‘‘Conditions of licenses.’’ The request
was issued in connection with
implementing lessons-learned identified
by the staff, and described in their NearTerm Task Force Report, following the
2011 accident at the Fukushima Dai-ichi
nuclear power plant. In connection with
this request, owners and operators were
to re-evaluate flood hazards at their
respective sites using present-day
methods and regulatory guidance used
by the NRC staff when reviewing 10
CFR part 52 applications for Early Site
PO 00000
Frm 00043
Fmt 4703
Sfmt 4703
50913
Permits and Combined Operating
Licenses.
In response to the staff’s 2012
§ 50.54(f) information request, owners
and licensees submitted about 60
external flood hazard re-evaluation
reports (FHRRs) corresponding to the
operating fleet of power reactors. In the
matter of the probable maximum
precipitation (PMP) value used for some
of the flood-hazard re-evaluations
(primarily the estimation of local
intense precipitation and riverine-based
floods), current NRC guidance
documents recommend the use of the
PMP estimation methods described in a
series of Hydrometeorological Reports
(HMRs) developed by the National
Oceanographic and Atmospheric
Administration (NOAA). The PMP event
itself is generally defined as the greatest
depth of precipitation for a given
duration meteorologically possible for a
design watershed or a given storm area
at a particular time of year. The
estimated PMP over a particular
watershed or basin results in a flood
magnitude for which there is virtually
no risk of exceeding. The challenge,
however, is that HMR-derived PMP
estimates are based on methodologies
and data which have not been updated
with rainfall and storm events which
have occurred in the decades since the
HMRs were last published.
Upon review of the FHRRs, the staff
found that about 26 project sites
responding to the § 50.54(f) information
request submitted PMP estimates that
were not based on NOAA HMRs but
were developed by a commercial
interest. As part of the FHRR process,
the staff conducted an audit of the
commercial vendor who developed the
site-specific PMP estimates to betterunderstand the technical basis
underlying the approach. In all cases,
these SSPMP estimates were less than
those obtained from the applicable
HMR. Although the development and
estimation of the SSPMP studies
reviewed by the staff generally followed
processes similar to those described in
the existing guidance, several different
methods, data sources, assumptions,
and procedures were used to obtain site
specific results other than those found
using the HMR methodology.
Based on the staff’s § 50.54(f) review
experience and in anticipation of its
continued use, this NUREG summarizes
the lessons-learned concerning the
review and application of a SSPMP. To
that end, this NUREG addresses the
following topics:
• Storm Selection
• Storm Reconstruction
• Storm Transposition
E:\FR\FM\13SEN1.SGM
13SEN1
50914
Federal Register / Vol. 86, No. 174 / Monday, September 13, 2021 / Notices
lotter on DSK11XQN23PROD with NOTICES1
• Storm Representative Dew Point
Selection
• Precipitable Water Estimation
• Dew Point Climatology, Moisture
Maximization, and Moisture
Transposition
• Terrain Adjustment
• Envelopment and Probable Maximum
Precipitation Determination
• Spatial and Temporal Distributions
for SSPMP Applications
This reference document describes
the technical theory, data sources, and
analysis methodology that could be
used to derive a SSPMP estimate.
Certain new terms are also introduced
and defined. This reference document
also identifies key technical
(meteorological) considerations when
reviewing a SSPMP estimate.
To date, there is no clear NRC
guidance on this topic or a commonly
agreed-to approach on the estimation of
SSPMP. As the staff may be reviewing
additional SSPMP estimates in the
future in connection with its regulatory
responsibilities, it was decided to elicit
stakeholder views on the matters and
approaches discussed in this draft
document.
This document contains no regulatory
guidance or regulatory positions.
A request for comments on draft
NUREG/KM–0015, (ADAMS Accession
No. ML20356A293) was published in
the Federal Register on December 29,
2020 (85 FR 85683), with a 60-day
comment period ending on March 1,
2021. Comments received on NUREG/
KM–0015 can be found on the Federal
Rulemaking website (https://
www.regulations.gov) under Docket ID
NRC–2020–0237.
II. Knowledge Management
Since its inception, the Atomic
Energy Commission and its successor,
the NRC, have focused on preserving the
(explicit) documentary record of its
decision-making in the form of
NUREGs, SECY Papers, Regulatory
Guides, and other documents. However,
in 2006, the agency recognized that
there was a need to engage in a moreformal program of knowledge
management that also reflects the lesstangible (implicit) human capital aspect
of the agencies’ knowledge base. This
feature was particularly important as the
agency enters its fifth decade of
operation—a period characterized by an
increasing number of retirements among
long-serving staff involved in many of
the agencies’ early regulatory programs
and associated licensing actions. Staff
efforts thus far in preserving this legacy
of experience that describe important
historical events, facts, and research that
were instrumental in shaping NRC’s
VerDate Sep<11>2014
17:39 Sep 10, 2021
Jkt 253001
regulatory programs, can be found at
https://www.nrc.gov/reading-rm/doccollections/nuregs/knowledge/.
The purpose of this knowledge
management NUREG (or NUREG/KM) is
intended to satisfy an NRC goal of
maintaining and preserving knowledge
concerning the lessons-learned from the
recent flood hazard re-evaluations at
current and planned nuclear power
plant sites performed most recently in
connection with the staff 2012 § 50.54(f)
reviews.
Dated: September 8, 2021.
For the Nuclear Regulatory Commission.
Luissette Candelario-Quintana,
Project Manager, External Hazards Branch,
Division of Engineering and External
Hazards, Office of Nuclear Reactor
Regulation.
[FR Doc. 2021–19636 Filed 9–10–21; 8:45 am]
BILLING CODE 7590–01–P
NUCLEAR REGULATORY
COMMISSION
[NRC–2021–0038]
Safety-Related Steel Structures and
Steel-Plate Composite Walls for Other
Than Reactor Vessels and
Containments
Nuclear Regulatory
Commission.
ACTION: Regulatory guide; issuance;
correction.
AGENCY:
The U.S. Nuclear Regulatory
Commission (NRC) is correcting a notice
that was published in the Federal
Register (FR) on September 7, 2021,
regarding the issuance of Regulatory
Guide (RG) 1.243, ‘‘Safety-Related Steel
Structures and Steel-Plate Composite
Walls for other than Reactor Vessels and
Containments.’’ This action is necessary
to correct the NRC Docket ID in the
notice title and the ADDRESSES section
and to correct a date in the Additional
Information section.
DATES: The correction takes effect on
September 13, 2021.
ADDRESSES: Please refer to Docket ID
NRC–2021–0038 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–2021–0038. Address
questions about Docket IDs in
Regulations.gov to Stacy Schumann;
telephone: 301–415–0624; email:
Stacy.Schumann@nrc.gov. For technical
questions, contact the individuals listed
SUMMARY:
PO 00000
Frm 00044
Fmt 4703
Sfmt 9990
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, 301–
415–4737, or by email to pdr.resource@
nrc.gov. The ADAMS accession number
for each document referenced (if it is
available in ADAMS) is provided the
first time that it is mentioned in this
document.
• Attention: The PDR, where you may
examine and order copies of public
documents, is currently closed. You
may submit your request to the PDR via
email at pdr.resource@nrc.gov or call 1–
800–397–4209 or 301–415–4737,
between 8:00 a.m. and 4:00 p.m. (ET),
Monday through Friday, except Federal
holidays.
RG 1.243 and the regulatory analysis
may be found in ADAMS under
Accession Nos. ML21089A032 and
ML20339A559, respectively.
Regulatory guides are not
copyrighted, and NRC approval is not
required to reproduce them.
FOR FURTHER INFORMATION CONTACT:
Edward O’Donnell, telephone: 301–415–
3317, email: Edward.ODonnell@nrc.gov
and Marcos Rolon Acevedo, telephone:
301–415–2208, email:
Marcos.RolonAcevedo@nrc.gov. Both
are staff of the Office of Nuclear
Regulatory Research at the U.S. Nuclear
Regulatory Commission, Washington,
DC 20555–0001.
SUPPLEMENTARY INFORMATION: In the FR
on September 7, 2021, in FR Doc. 2021–
19178, on page 50190, in the notice title
after agency name correct ‘‘NRC–2020–
0038’’ to read ‘‘NRC–2021–0038.’’ In the
ADDRESSES section, first sentence correct
NRC Docket ID ‘‘NRC–2020–0038’’ to
read ‘‘NRC–2021–0038’’ and in the first
bullet of the ADDRESSES section, first
sentence, correct ‘‘NRC–2020–0038’’ to
read ‘‘NRC–2021–0038.’’ In the
Additional Information section, correct
‘‘March 29, 2020’’ to read ‘‘March 29,
2021.’’
Dated: September 7, 2021.
For the Nuclear Regulatory Commission.
Meraj Rahimi,
Branch Chief, Regulatory Guide and Programs
Management Branch, Division of Engineering,
Office of Nuclear Regulatory Research.
[FR Doc. 2021–19621 Filed 9–10–21; 8:45 am]
BILLING CODE 7590–01–P
E:\FR\FM\13SEN1.SGM
13SEN1
]]>Agencies
[Federal Register Volume 86, Number 174 (Monday, September 13, 2021)]
[Notices]
[Pages 50913-50914]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-19636]
=======================================================================
-----------------------------------------------------------------------
NUCLEAR REGULATORY COMMISSION
[NRC-2020-0237]
Considerations for Estimating Site-Specific Probable Maximum
Precipitation at Nuclear Power Plants in the United States of America
AGENCY: Nuclear Regulatory Commission.
ACTION: NUREG; issuance.
-----------------------------------------------------------------------
SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing a
knowledge management NUREG, NUREG/KM-0015, ``Considerations for
Estimating Site-Specific Probable Maximum Precipitation at Nuclear
Power Plants in the United States of America.'' The NRC staff and Oak
Ridge National Laboratory have prepared a reference document
summarizing recent lessons-learned in connection with a review of the
site-specific probable maximum precipitation (SSPMP) estimates used by
some nuclear power plant owners and operators in connection with a
recent re-evaluation of external flooding at their respective project
sites.
DATES: NUREG/KM-0015 is available on September 13, 2021.
ADDRESSES: Please refer to Docket ID NRC-2020-0237 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-2020-0237. 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, 301-415-4737, or
by email to [email protected]. NUREG/KM-0015, ``Considerations for
Estimating Site-Specific Probable Maximum Precipitation at Nuclear
Power Plants in the United States of America'' is available in ADAMS
under Accession No. ML21245A418.
Attention: The PDR, where you may examine, and order
copies of public documents, is currently closed. You may submit your
request to the PDR via email at [email protected] or call 1-800-397-
4209 or 301-415-4737, between 8:00 a.m. and 4:00 p.m. (ET), Monday
through Friday, except Federal holidays.
FOR FURTHER INFORMATION CONTACT: Kevin Quinlan, Office of Nuclear
Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001; telephone: 301-415-6809, email: [email protected].
SUPPLEMENTARY INFORMATION:
I. Background
By letter dated March 12, 2012, the NRC issued a request for
information to all power reactor licensees and holders of construction
permits in active or deferred status licensees to reevaluate seismic
and external flooding for their sites against current Commission
requirements and guidance. This request was made consistent with
paragraph 50.54(f) of title of the Code of Federal Regulations (10
CFR), ``Conditions of licenses.'' The request was issued in connection
with implementing lessons-learned identified by the staff, and
described in their Near-Term Task Force Report, following the 2011
accident at the Fukushima Dai-ichi nuclear power plant. In connection
with this request, owners and operators were to re-evaluate flood
hazards at their respective sites using present-day methods and
regulatory guidance used by the NRC staff when reviewing 10 CFR part 52
applications for Early Site Permits and Combined Operating Licenses.
In response to the staff's 2012 Sec. 50.54(f) information request,
owners and licensees submitted about 60 external flood hazard re-
evaluation reports (FHRRs) corresponding to the operating fleet of
power reactors. In the matter of the probable maximum precipitation
(PMP) value used for some of the flood-hazard re-evaluations (primarily
the estimation of local intense precipitation and riverine-based
floods), current NRC guidance documents recommend the use of the PMP
estimation methods described in a series of Hydrometeorological Reports
(HMRs) developed by the National Oceanographic and Atmospheric
Administration (NOAA). The PMP event itself is generally defined as the
greatest depth of precipitation for a given duration meteorologically
possible for a design watershed or a given storm area at a particular
time of year. The estimated PMP over a particular watershed or basin
results in a flood magnitude for which there is virtually no risk of
exceeding. The challenge, however, is that HMR-derived PMP estimates
are based on methodologies and data which have not been updated with
rainfall and storm events which have occurred in the decades since the
HMRs were last published.
Upon review of the FHRRs, the staff found that about 26 project
sites responding to the Sec. 50.54(f) information request submitted
PMP estimates that were not based on NOAA HMRs but were developed by a
commercial interest. As part of the FHRR process, the staff conducted
an audit of the commercial vendor who developed the site-specific PMP
estimates to better-understand the technical basis underlying the
approach. In all cases, these SSPMP estimates were less than those
obtained from the applicable HMR. Although the development and
estimation of the SSPMP studies reviewed by the staff generally
followed processes similar to those described in the existing guidance,
several different methods, data sources, assumptions, and procedures
were used to obtain site specific results other than those found using
the HMR methodology.
Based on the staff's Sec. 50.54(f) review experience and in
anticipation of its continued use, this NUREG summarizes the lessons-
learned concerning the review and application of a SSPMP. To that end,
this NUREG addresses the following topics:
Storm Selection
Storm Reconstruction
Storm Transposition
[[Page 50914]]
Storm Representative Dew Point Selection
Precipitable Water Estimation
Dew Point Climatology, Moisture Maximization, and Moisture
Transposition
Terrain Adjustment
Envelopment and Probable Maximum Precipitation Determination
Spatial and Temporal Distributions for SSPMP Applications
This reference document describes the technical theory, data
sources, and analysis methodology that could be used to derive a SSPMP
estimate. Certain new terms are also introduced and defined. This
reference document also identifies key technical (meteorological)
considerations when reviewing a SSPMP estimate.
To date, there is no clear NRC guidance on this topic or a commonly
agreed-to approach on the estimation of SSPMP. As the staff may be
reviewing additional SSPMP estimates in the future in connection with
its regulatory responsibilities, it was decided to elicit stakeholder
views on the matters and approaches discussed in this draft document.
This document contains no regulatory guidance or regulatory
positions.
A request for comments on draft NUREG/KM-0015, (ADAMS Accession No.
ML20356A293) was published in the Federal Register on December 29, 2020
(85 FR 85683), with a 60-day comment period ending on March 1, 2021.
Comments received on NUREG/KM-0015 can be found on the Federal
Rulemaking website (https://www.regulations.gov) under Docket ID NRC-
2020-0237.
II. Knowledge Management
Since its inception, the Atomic Energy Commission and its
successor, the NRC, have focused on preserving the (explicit)
documentary record of its decision-making in the form of NUREGs, SECY
Papers, Regulatory Guides, and other documents. However, in 2006, the
agency recognized that there was a need to engage in a more-formal
program of knowledge management that also reflects the less-tangible
(implicit) human capital aspect of the agencies' knowledge base. This
feature was particularly important as the agency enters its fifth
decade of operation--a period characterized by an increasing number of
retirements among long-serving staff involved in many of the agencies'
early regulatory programs and associated licensing actions. Staff
efforts thus far in preserving this legacy of experience that describe
important historical events, facts, and research that were instrumental
in shaping NRC's regulatory programs, can be found at https://www.nrc.gov/reading-rm/doc-collections/nuregs/knowledge/.
The purpose of this knowledge management NUREG (or NUREG/KM) is
intended to satisfy an NRC goal of maintaining and preserving knowledge
concerning the lessons-learned from the recent flood hazard re-
evaluations at current and planned nuclear power plant sites performed
most recently in connection with the staff 2012 Sec. 50.54(f) reviews.
Dated: September 8, 2021.
For the Nuclear Regulatory Commission.
Luissette Candelario-Quintana,
Project Manager, External Hazards Branch, Division of Engineering and
External Hazards, Office of Nuclear Reactor Regulation.
[FR Doc. 2021-19636 Filed 9-10-21; 8:45 am]
BILLING CODE 7590-01-P
