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| {{#Wiki_filter:June 16, 2021 LICENSEE: Dominion Energy Virginia FACILITY: Surry, Units 1 and 2 | | {{#Wiki_filter:}} |
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| ==SUBJECT:==
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| SURRY UNITS 1 AND 2 - MAY 20, 2021,
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| ==SUMMARY==
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| REGARDING PRE-APPLICATION MEETING TO DISCUSS PLANNED LICENSE AMENDMENT REQUESTS On May 20, 2021, an Observation Meeting was held between the U.S. Nuclear Regulatory Commission (NRC) and representatives of Dominion Energy Virginia (Dominion Energy, the licensee). The purpose of the meeting was for Dominion Energy to provide planned amendments for Surry Power Station, Units 1 and 2. The planned amendments would modify the licensing basis for the turbine building (TB) and the fuel handling trolley support structures (FHTSS) relative to tornado effects. The meeting notice and agenda dated May 7, 2021, are available in Agencywide Documents Access and Management System (ADAMS) at Accession No. ML21130A055. The licensees presentation is available in ADAMS at Accession No. ML21134A163. A list of participants is provided in the Enclosure.
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| The licensee discussed the current licensing basis, the deficiencies of the analyses, and the basis for the current operability of the TB and the FHTSS in relation to the tornado wind speed of 360 miles per hour (mph). The licensee presented information regarding the planned license amendment requests (LARs) to modify the licensing basis for the TB from tornado wind speed 360 mph to 250 mph using a deterministic method and for the FHTSS using a risk-informed approach to reduce the tornado wind speed from 360 mph to 210 mph. For both structures, the licensee presented its reason for the license amendment changes, the analytical methods used, details of the analysis performed, and the results.
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| In its Updated Final Safety Analysis Report (UFSAR), the licensee identified analyses deficiencies of the effects of tornado winds on the both the FHTSS and the TB steel superstructure. The licensee cannot demonstrate by analyses the structural integrities of the TB and the FHTSS under tornado wind speed of 360 mph from its UFSAR. The TB is a non-safety related structure, but there are safety-related systems, such as, service water system and recirculation system that are located at the basement elevation of the TB. The FHTSS is a safety related structure. Dominion Energy presented a new deterministic analytical approach for the TB under tornado wind speed of 250 mph, and a new risk-informed approach for the FHTSS to determine minimal risk of fuel damage in the spent fuel pool (SFP) due to possible collapse of the FHTSS under tornado wind speeds. The NRC staff suggested that the licensee should consider submitting separate LARs for both structures, because the analytical approach for analyzing the effect of the tornado wind speeds are different. In response, the licensee acknowledged thats one approach Dominion Energy has been discussing internally.
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| Regarding the FHTSS, the licensee is proposing to use a risk-informed approach to support the proposed licensing basis change, using Regulatory Guide 1.174, Revision 3, An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis, dated January 2018 (ADAMS Accession No. ML17317A256). To address risk quantification, the licensee proposed to compare core damage frequency changes to the frequency of uncovered fuel in the FHTSS. The NRC staff suggested that the risk comparison would make more sense if, instead of core damage frequency, the licensee would consider changes in large early release frequency and a high-level consequence analysis. Also, the NRC staff stated that all 5 principles of risk-informed decision-making should be fully addressed in the Dominion Energys submittal.
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| The licensee plans to submit its license amendment request by the end of the third quarter of calendar year (CY) 2021 and request approval in the third quarter of CY 2022.
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| No members of the public were in attendance. No regulatory decisions were made in the meeting.
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| Please direct any inquiries to me at 301-415-5897 or Vaughn.Thomas@nrc.gov.
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| /RA/
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| Vaughn Thomas, Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos.: 50-280 and 50-281
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| ==Enclosure:==
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| List of Attendees cc: Listserv
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| LIST OF PARTICIPANTS MAY 20, 2021 PRE-APPLICATION PUBLIC CONFERENCE CALL WITH DOMINION ENERGY VIRGINIA PRPOSED LICENSED AMENDMENT REQUEST FOR THE TURBINE BUILDING AND THE FUEL BUILDING Name Organization Vaughn Thomas U.S. Nuclear Regulatory Commission Milton Valentin U.S. Nuclear Regulatory Commission De Wu U.S. Nuclear Regulatory Commission John Ma U.S. Nuclear Regulatory Commission Ata Istar U.S. Nuclear Regulatory Commission Stephanie Delvin-Gill U.S. Nuclear Regulatory Commission Michael Markley U.S. Nuclear Regulatory Commission Dana Knee Dominion Energy Joe Vasquez Dominion Energy Alireza Nojavan Dominion Energy Chuck Zalesiak Dominion Energy Isaiah Hertzig Dominion Energy John Harrell Dominion Energy Thomas Jaeger Dominion Energy Robert Ewing Dominion Energy Meagan Provinsal Dominion Energy Gary Miller Dominion Energy Adina LaFrance Dominion Energy Stephen Newman Dominion Energy Fred Grant Dominion Energy Tim Graff Dominion Energy Alex Dean Dominion Energy Craig Swanner Dominion Energy Enclosure
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| ML21159A093 OFFICE NRR/DORL/LPL2-1/PM NRR/DORL/LPL2-1/LA NRR/DORL/LPL2-1/BC NAME VThomas KGoldstein MMarkley (JLamb for)
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| DATE 06/08/2021 06/15/2021 6/16/2021 OFFICE NRR/DORL/LPL2-1/PM NAME VThomas DATE 06/16/2020}}
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