ML21197A201
| ML21197A201 | |
| Person / Time | |
|---|---|
| Site: | 99902037 |
| Issue date: | 08/03/2021 |
| From: | Leslie Fields Licensing Processes Branch |
| To: | Dennis Morey Licensing Processes Branch |
| Fields L | |
| Shared Package | |
| ML21197A206 | List: |
| References | |
| Download: ML21197A201 (5) | |
Text
August 3, 2021 MEMORANDUM TO:
Dennis C. Morey, Chief Licensing Processes Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM:
Leslie C. Fields, Senior Project Manager /RA/
Licensing Processes Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
SUBJECT:
SUMMARY
OF THE OCTOBER 14, 2020, PUBLIC MEETING REGARDING THE PRE-SUBMITTAL OF TOPICAL REPORT PWROG-18068, USE OF DIRECT FRACTURE TOUGHNESS FOR EVALUATION OF REACTOR PRESSURE VESSEL INTEGRITY On October 14, 2020, the U.S. Nuclear Regulatory Commission (NRC) staff held a public meeting with the Pressurized Water Reactor Owners Group (PWROG) and industry representatives to discuss Topical Report (TR) PWROG-18068, Use of Direct Fracture Toughness for Evaluation of Reactor Pressure Vessel Integrity, prior to submittal to the NRC for review and approval. The meeting gave industry the opportunity to discuss the TR methodology associated with reactor pressure vessel (RPV) integrity as an alternative to meet the requirements of pressurized thermal shock (PTS) (Title 10 of the Code of the Federal Regulations (10 CFR) 50.61) and pressure-temperature (P-T) limit curves (10 CFR Part 50, Appendix G). The meeting notice and presentation slides are publicly available in the Agencywide Documents Access and Management System (ADAMS) under Package Accession No. ML21197A206. The list of meeting attendees is enclosed.
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Background===
On March 2, 2016, the NRC staff conducted a public meeting for the PWROG to present its plan for transitioning RPV integrity (ADAMS No. ML16208A412) to direct fracture toughness. During the meeting, the NRC staff asked the PWROG representatives about the plan to evaluate test results from a data sample to ensure that the variability in the RPV will be addressed through the adjustments to data and/or uncertainty terms. Additionally, the NRC staff inquired about how the PWROG plans to address: 1) the adequacy of the mini-C(T) specimen size, 2) the Material Test Reactor flux effect and irradiation temperature, 3) the consideration of adding the PTS limiting materials to the test matrix, and 4) other materials that are not tested which could become limiting. To address the NRC staffs comments, the PWROG made changes/updates to the methodology of TR PWROG-18068 which was the subject of the October 14, 2020, meeting.
CONTACT:
Leslie Fields, NRR/DORL 301-415-1186
Discussion The meeting provided the PWROG the opportunity to discuss a forthcoming TR methodology that will potentially: 1) generate irradiated master curve reference temperature (T0) data,
- 2) adjust data for differences between the tested material and the RPV component of interest,
- 3) account for test result uncertainty and material variability in the respective RPV component, and 4) apply data using a robust bases and the American Society of Mechanical EngineersSection XI Code.
As a part of the high-level summary, the PWROG representatives stated that the potential benefits of an irradiated direct fracture toughness data evaluation methodology could establish a robust fracture toughness basis for license renewal terms and provide potential savings for both the NRC and its licensees for managing RPV integrity. In addition, according to the PWROG, the methodology could ensure public safety by enabling a statistical understanding for the existing safety margin.
Final Comments and Path Forward At the conclusion of the meeting, the PWROG representatives presented conclusions and stated that TR PWROG-18068 is currently planned to be submitted in March of 2021.
In addition, there was an opportunity for the public to provide comments and ask questions. No public comments were received, and the meeting was concluded.
Docket No. 99902037
Enclosure:
List of Meeting Attendees
ML21197A206 (Package)
ML20272A297 (Notice)
ML20294A116 (Slides)
ML21197A201 (Summary)
OFFICE NRR/DORL/LLPB/PM NRR/DORL/LLPB/LA NRR/DORL/LLPB/BC NRR/DORL/LLPB/PM NAME LFields DHarrison DMorey LFields DATE 07/19/2021 07/19/2021 07/22/2021 08/03/2021
Enclosure
SUMMARY
OF THE OCTOBER 14, 2020, PUBLIC MEETING REGARDING THE PRE-SUBMITTAL OF TOPICAL REPORT PWROG-18068 Name Organization E-mail Leslie Fields U.S. Nuclear Regulatory Commission (NRC) leslie.fields@nrc.gov Hipolito Gonzalez NRC hipolito.gonzolez@nrc.gov David Rudland NRC david.rudland@nrc.gov Steven Bloom NRC steven.bloom@nrc.gov Jeffrey Poehler NRC jeffrey.poehler@nrc.gov Allen Hiser NRC allen.hiser@nrc.gov Michael Benson NRC michael.benson@nrc.gov Carolyn Fairbanks NRC carolyn.fairbanks@nrc.gov David Dijamco NRC david.dijamco@nrc.gov John Tsao NRC john.tsao@nrc.gov Dan Widrevitz NRC dan.widrevitz@nrc.gov Jim Hickey NRC james.hickey@nrc.gov Ganesh Cheruvenki NRC ganesh.cheruvenki@nrc.gov Siva Lingham NRC siva.lingam@nrc.gov Nicholas Hansing NRC nicholas.hansing@nrc.gov Damion Mirizio Westinghouse Electric Company (Westinghouse) mirizids@westinghouse.com Jim Andrachek Westinghouse andracjd@westinghouse.com Jim Molkenthin Westinghouse molkenjp@westinghouse.com Tim Wells Southern Co.
tgwells@southernco.com Chris Koehler Xcel Energy christopher.koehler@xenuclear.com Brian Hall Westinghouse halljb@westinghouse.com
SUMMARY
OF THE OCTOBER 14, 2020, PUBLIC MEETING REGARDING THE PRE-SUBMITTAL OF TOPICAL REPORT PWROG-18068 Name Organization E-mail Jim Andrachek Westinghouse andracjd@westinghouse.com Jim Molkenthin Westinghouse molkenjp@westinghouse.com Matt DeVan Framatome, Inc.
(Framatome) matt.devan@framatome.com Ray Stewart Framatome ray.stewart@framatome.com Amy E. Freed Electric Power Research Institute (EPRI) afreed@epri.com Elliot J. Long EPRI elong@epri.com Gary Miller Dominion Energy gary.d.miller@dominionenergy.com Susan Ortner National Nuclear Laboratory Limited susan.r.ortner@uknnl.com Jana Bergman Curtiss Wright jbergman@curtisswright.com