ML24102A194

Summary of the March 8, 2024 RG 1-183 Update Workshop (3 of 3)

ML24102A194
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Issue date:	03/08/2024
From:	Garmon D Office of Nuclear Reactor Regulation
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Download: ML24102A194 (5)

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U.S. Nuclear Regulatory Commission Public Meeting Summary

Title:

NRC Hybrid Workshop (3 of 3) - Update to RG 1.183, Revision 1, "Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors"

Meeting Identifier: 20240279

Date of Meeting: March 8, 2024

Location: Hybrid (NRC Headquarters, Rockville, MD and via Microsoft Team s)

Type of Meeting: Comment Gathering Public Meeting

Purpose of Meeting: The NRC hosted three workshops in early 2024 to discuss a revi sion to Regulatory Guide (RG) 1.183, Revision 1, Alternative Radiologi cal Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23082A305). These wor kshops provided opportunities for NRC staff to discuss updates to extend the ap plicability of the guidance to higher burnup and increased enrichment fuel applications, in su pport of the NRCs Increased Enrichment Rulemaking (https://www.regulations.gov/document/NRC-2020-0034-0005 ), and to consider other feedback that is relevant to the guidance. The w orkshops allowed for the NRCs external stakeholders to participate in the regulatory process through a comment gathering format as described in the NRCs policy statement on public mee tings at 86 FR 14964. The staff collected comments and input through note-taking and will consi der this information while drafting updates to guidance.

Related Documents:

• ML24067A288 - RG 1-183 Public Workshop (3 of 3) - External Slides - Non-LOCA Release Fraction Feedback

• ML24066A177 - RG 1-183 Public Workshop (3 of 3) - NRC Slides

• ML24067A004 - RG 1-183 Public Workshop (3 of 3) - External Slides

• ML24068A036 - RG 1-183 Public Workshop (3 of 3) - Update to RG 1.183, Revisio n 1, "Alternative Radiological Source Terms for Evaluating Design Ba sis Accidents at Nuclear Power Reactors" - NRC Meeting Notice

Summary:

On March 8, 2024, the NRC staff held a workshop, formally known as a comment gathering public meeting, to discuss the revision of RG 1.183, Revision 1. This workshop included presentations by the NRC staff, representatives from the nuclea r industry, facilitated by the Nuclear Energy Institute (NEI), and representatives from the El ectric Power Research Institute (EPRI). The meeting provided an opportunity for NRC staff to di scuss updates to extend the applicability of RG 1.183 to higher burnup and increased enrich ment fuel applications in support of the NRCs Increased Enrichment Rulemaking ( https://regulations.gov under docket NRC-2020-0034) and to consider other feedback that is relevant to the guidance contained in the RG. The meeting notice is available at ADAMS Accession No. ML24 068A036. The NRC, Sandia

1 ADAMS Accession No. ML24102A194 National Laboratories (SNL) and industry meeting slides are ava ilable at ADAMS Accession Numbers listed in the Related Documents sections of this meetin g summary.

Michael X. Franovich, Director of the Division of Risk Assessme nt in the Office of Nuclear Reactor Regulation (NRR), made opening remarks. Following the o pening remarks, as required by the Commissions Policy Statement on Public Meetings (86 FR 14964), the staff described methods that stakeholders can use to provide input and feedback to the NRC and the staff clarified that comments regarding the NRCs Increased Enrichmen t Rulemaking should be submitted through the https://regulations.gov website under docket ID NRC-2020-0034.

The first presentation, given by NRC staff (ADAMS Accession No. ML24066A177), reviewed the plan to update RG 1.183, including a schedule that aligns the d raft guide development with the Increased Enrichment Rulemaking per Management Directive 6.6, Regulatory Guides, ADAMS Accession No. ML22010A233. The staff then provided an ove rview of a generalized framework for developing a graded, risk-informed methodology fo r control room design criteria to include: (1) Background on the agencys efforts to incorpora te risk considerations into its regulations; (2) An overview of several potential approaches to developing a licensee-specific, risk-informed control room design criteria; and (3) A compariso n of design basis accidents and actual event sequences. The staff then provided a presentation on the development of gap release fractions that apply to accidents other than the loss o f coolant accident (LOCA), known as non-LOCA release fractions. In this presentation the staff provided: (1) Background on gap release fractions, the applicability of the non-LOCA release fr actions in RG 1.183, Rev. 1, and the guidance to calculate release fractions for power histories and fuel designs that differ from those considered by the staff; (2) Draft non-LOCA gap release fractions for pressurized water reactors (PWRs) and boiling water reactors (BWRs); and (3) Prel iminary results of sensitivity studies for different fuel enrichments and trend analyses for d ifferent fuel rod-average burnup values.

The remainder of the workshop was dedicated to discussions and presentations provided by members of the industry and facilitated by NEI.

In the presentation entitled, Non-LOCA Release Fractions Feedb ack, (ADAMS Accession No. ML24067A288), presenters provided: (1) Fuel rod power vs. rod a verage burnup graphs for PWRs and BWRs for the staff to consider in development of non-L OCA release fractions; (2)

Proposed language for the draft guide to expand applicability t o higher burnup and increased enrichment fuels and to make the guidance more generic, as it p ertains to certain fuel designs; and (3) Proposed language for the draft guide intended to clari fy certain sections of Appendix I to RG 1.183, Rev. 1. As a correction to the meeting announcemen t, upon request of the presenters, this slide presentation was used in place of the pr esentation found at ADAMS Accession No. 24067A006.

In the presentation entitled, Non-LOCA Release Fractions Impac t from Fuel Fragmentation, Relocation and Dispersal [FFRD], (ADAMS Accession No. ML24067A 007), presenters provided: (1) Comments and discussion on the lack of guidance i n RG 1.183, Rev. 1 for non-LOCA FFRD and that this lack of guidance represents a significa nt gap for the industry; (2)

Commentary that conservatisms in the current analyses can be ap plied as a justification for concluding the current analyses are bounding of non-LOCA FFRD; and (3) Proposed language for the draft guide, regulatory position 3.2, to improve clarit y as it pertains to non-LOCA FFRD.

In the presentation entitled, Discussion of On-site and Off-si te Dose Criteria in RG 1.183, (ADAMS Accession No. ML24067A009), presenters provided: (1) A r eview of literature that

2 ADAMS Accession No. ML24102A194 supports changes to the control room design criteria; (2) Propo sed changes to Table 7 of RG 1.183, Rev. 1 that contains the criteria for public and control room locations; and (3) Discussion of a potential method for revising the current criteria.

In the presentation entitled, Impacts of RG 1.183 Rev. 1 and S AND2023-01313 on Environmental Qualification, (ADAMS Accession No. ML24067A010), the presenter provided a proposed approach to addressing what the industry perceives to be a lack of clarity in environmental qualification analyses. In its remarks the presen ter proposed that the NRC publish a Regulatory Issue Summary (RIS) that would be supporte d by an industry study to clarify the NRCs position on env ironmental qualification analyses.

In the presentation entitled, MAAP [Modular Accident Analysis Program] Alternate Source Term Research in Support of RG 1.183 Revision 2, (ADAMS Accession N o. ML24067A011),

presenters provided insights from industrys review of the resu lts of the Sandia Report No.

2023-01313, High Burnup Fuel Source Term Accident Sequence Ana lysis and feedback in certain technical areas for consideration.

In the presentation entitled, Best-Estimate Plus Uncertainty A pproaches to Dose Analysis, (ADAMS Accession No. ML24067A012), the presenters provided an e xplanation of an approach to applying best-estimate plus uncertainty methods to accident consequence analysis and the presenters provided proposed language for the draft guide to cl arify that best-estimate plus uncertainty approaches are acceptable and will be evaluated on a case-by-case basis.

Lastly, in the presentation entitled, Closing Remarks, (ADAMS Accession No, ML24067A013),

the presenters acknowledged the value of the workshop effort an d provided a list of industry priorities for the draft guide:

1. Provide method to credit decontamination in the suppression pool

2. Support an increase in CR dose design criteria

3. Development of updated decontamination coefficients using th e new phase durations for both BWR and PWR containments to be used by the downstream dose codes

4. Revise Non-LOCA Release Fractions in RG 1.183R1 Tables 3 and 4

5. Develop disposition for non-LOCA FFRD

6. Provide clarification via a RIS or other regulatory vehicle on EQ applicability for continued use of TID-14844 source term

7. Address excess conservatisms in the guidance where combined airborne and water releases are greater than the core inventory

8. Include flexibility in the guidance to apply statistical app roaches to dose calculations

Michael Franovich, Director of the Division of Risk Assessment in NRR provided closing remarks.

No regulatory decisions were made during the meeting.

3 ADAMS Accession No. ML24102A194 List of Attendees

March 8, 2024, Public Meeting NRC Hybrid Workshop (3 of 3) - Up date to RG 1.183, Revision 1, "Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors"

Name Affiliation Name Affiliation Lucas Albright Sandia National Don Lowman NRC Laboratories Don Algama US-DOE David Luxat Sandia National Laboratories Jill Anderson APS Edwin Lyman UCS Robert Austin EPRI Jim Lynde PWROG /

Constellation Joseph Azeizat NRC Alex Markivich Dominion Energy Uriel Bachrach Westinghouse Michael Markley NRC Steve Baker Baker Consulting Don Marksberry NRC Services LLC David Barrientos Global Nuclear Fuels - Tara Matheny Duke Energy America Razeen Basunia Constellation Matthew Mcconnell NRC Jana Bergman Curtiss-Alan Meginnis Framatome Wright/Scientech Dwayne Blaylock Enercon Service, Inc Sean Meighan NRC Mark Blumberg NRC Joseph Messina NRC Butch Bornt Southern Nuclear Ed Miller NRC Jan Bostelman Bostelman Engineering Barry Mingst TerraPower Andrew Bowman Westinghouse Brian Mount Dominion Energy Greg Broadbent Consultant Carole Naugle Framatome Kristy Bucholtz NRC Matthew Nudi EPRI Justin Byard Dominion Energy John Parillo NRC Shawn Campbell NRC Frances Pimentel NEI Daria Carini Holtec International Doug Pollock TVA Rob Choromokos EPRI Steven Pope ISL, Inc Paul Clifford Framatome Ian Porter Global Nuclear Fuels - America Joe Coletta Duke Energy Meraj Rahimi NRC Aladar Csontos NEI William Rautzen NRC Kristopher Cummings NuScale Power James Richter PSEG Nuclear Bridget Curran NRC Malinda Saia Holtec International Elijah Dickson NRC Michael Salay NRC Mitchell Dior BWROG Baris Sarikaya Constellation Dennis Earp Duke Energy Jason Schaperow NRC Thomas Eichenberg TVA Harold Scott None Hossein Esmaili NRC John Segala NRC

4 ADAMS Accession No. ML24102A194 List of Attendees

March 8, 2024, Public Meeting NRC Hybrid Workshop (3 of 3) - Up date to RG 1.183, Revision 1, "Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors"

Name Affiliation Name Affiliation Michael Eudy NRC Carlos Sisco Winston & Strawn (NUGEQ)

Fernando Ferrante EPRI Fred Smith EPRI John Fisher Energy Northwest Paul Smith Framatome Michael Franovich NRC Micheal Smith NEI Jeff Gabor EPRI Ashley Smith NRC Lisa Gerken Framatome James Stavely PSEG Nuclear Zachary Gran NRC Charles Stroupe Duke Energy Michelle Hart NRC Ed Stutzcage NRC Kevin Hsueh NRC Christie Taylor Duke Energy Caryl Ingram Duke Energy Scott Thomas Duke Energy Randy Jacobs GEH John Tomon NRC Meena Khanna NRC Lei Tu Constellation Thomas Kindred Southern Nuclear Chris Van Wert NRC Audrey Klett NRC Daniel Vincent American Electric Power Jeffrey Kobelak Westinghouse Kalene Walker None Andrea Kock NRC Kim Webber NRC Bill Kohlroser Dominion Energy Sunil Weerakkody NRC David Kortge Constellation Ron Wise Nuclear Utility Group on Equipment Qualification (NUGEQ)

Sam Lafountain Southern Nuclear Laith Zaidan Holtec Internation al Rick Loeffler Xcel Energy Devshibhai Ziyad Holtec International

5 ADAMS Accession No. ML24102A194