Federal Register / Vol. 86, No. 174 / Monday, September 13, 2021 / Notices 50913 

which restricts (with limited 

exceptions) assistance for the central 

government unless the Secretary makes 

certain certifications regarding actions 

taken by the Government of Sri Lanka 

and reports to the Committees on 

Appropriations. 

Countries identified above as 

candidate countries, as well as countries 

that would be considered candidate 

countries but for the applicability of 

legal provisions that prohibit U.S. 

economic assistance, may be the subject 

of future statutory restrictions or 

determinations, or changed country 

circumstances, that affect their legal 

eligibility for assistance under part I of 

the Foreign Assistance Act by reason of 

application of the Foreign Assistance 

Act or any other provision of law for FY 

2022. 

[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 

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: 

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 

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 


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50914 Federal Register / Vol. 86, No. 174 / Monday, September 13, 2021 / Notices 

• 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 

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 

AGENCY: Nuclear Regulatory 

Commission. 

ACTION: Regulatory guide; issuance; 

correction. 

SUMMARY: 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 

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 


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