ML24306A007
| ML24306A007 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 06/26/2024 |
| From: | Joel Wiebe NRC/NRR/DORL/LPL3 |
| To: | Zurawski L Constellation Energy Generation |
| References | |
| L-2024-LLR-0042 | |
| Download: ML24306A007 (4) | |
Text
From:
Joel Wiebe Sent:
Wednesday, June 26, 2024 11:41 AM To:
Zurawski, Lisa M:(Constellation Nuclear)
Subject:
Verbal Relief for Byron, Unit 2, Three Specific Air-operated Valves in the Essential Service Water System (L-2024-LLR-0042)
Hi Lisa, This email serves as documentation of the verbal relief that NRC provided on June 26, 2024.
This email will be made publicly available. A written Safety Evaluation (SE) will be issued at a later date in accordance with NRR Office Instruction LIC-102. This verbal authorization does not preclude the NRC staff from asking additional clarification questions while preparing the written SE.
Joel S. Wiebe Senior Project Manager 301-415-6606 VERBAL AUTHORIZATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION HARDSHIP ALTERNATIVE REQUEST FOR INSERVICE TESTING INTERVAL EXTENSION FOR ESSENTIAL SERVICE WATER VALVES DUE TO REQUIRED USE OF CONTAINMENT CHILLER CONSTELLATION ENERGY GENERATION, LLC BYRON STATION, UNIT 2 DOCKET NO. 50-455 EPID: L-2024-LLR-0042 Technical Evaluation read by Stewart Bailey, Chief of the Mechanical Engineering and Inservice Testing Branch, Division of Engineering and External Hazards, NRC Office of Nuclear Reactor Regulation In your letter dated June 25, 2024, you proposed to delay the inservice testing of three specific air-operated valves in the Essential Service Water System at Byron, Unit 2, until after the 2A Containment Chiller is returned to operable status. Testing these valves would take the 2B Containment Chiller out of service. For reasons discussed in the letter, taking the 2B Containment Chiller out of service while the 2A Containment Chiller is out of service has adverse impacts on other plant equipment and increases the chances of a plant shutdown at a time when there are grid alert conditions. Therefore, you asked for a one-time extension of the testing under the provisions of 10 CFR 50.55a(z)(2).
The current requirement is for these valves to be tested every three months. This requirement comes from your Fourth 10-year Inservice Testing program, which is based on the 2004 Edition through 2006 Addenda of the American Society of Mechanical Engineers Code for the Operation and Maintenance of Nuclear Power Plants. The testing is due today, June 25, 2024. Your proposed alternative is to delay
testing of these three valves until after the 2A Containment Chiller is returned to operable status, but no later than July 19, 2024.
Your submittal states that the required inservice testing for the three specified valves consists of exercise, fail-safe and valve stroke testing. The submittal summarizes the history of the test results for the subject valves. The data show that the stroke time testing has been completed satisfactorily over the past 2 years and first quarter of 2024. Additionally, the submittal states that no deficiencies, adverse trends, or open maintenance work orders are active that would impact or degrade the performance capability of these valves, and that each valve is currently on a standard testing interval with acceptable performance. On this basis, you conclude that there is reasonable assurance that each valve will continue to be capable of performing its design function during the requested interval.
The NRC staff has reviewed your proposed one-time extension. The staff finds that compliance with the specified inservice testing requirements during the short duration of the alternative would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. Taking the 2B Containment Chiller out of service while the 2A Containment Chiller is out of service could have adverse impacts on other plant equipment and increase the probability of a plant shutdown during grid alert conditions. Also, the test and performance history for the specified valves provides reasonable assurance of their operational readiness during the time period of the alternative request. Therefore, the NRC staff concludes that the proposed alternative meets the requirements of 10 CFR 50.55a(z)(2). The staff authorizes the one-time extension of testing on the three specific air-operated valves until restoration of the 2A Containment Chiller to operable status, but no later than July 19, 2024. This one-time extension does not extend the end date of the Byron Unit 2, Fourth 10-Year Inservice Testing Program interval beyond June 30, 2026.
Authorization read by Jeff Whited As Chief of the Plant Licensing Branch3, Office of Nuclear Reactor Regulation, I concur with the conclusions of the Mechanical Engineering and Inservice Testing Branch.
The NRC staff determines that the proposed alternative provides reasonable assurance that the three specified Essential Service Water System valves will be operationally ready for the duration of the alternative. The NRC staff determined that compliance with the applicable ASME OM Code test requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. Accordingly, the NRC staff concludes that the licensee has adequately addressed all regulatory requirements set forth in 10CFR50.55a(z)(2).
Therefore, as of today, June 26, 2024, the NRC staff authorizes the use of the proposed alternative for a one-time extension to the Inservice Testing Program 3-month intervals only for testing of the three specified Essential Service Water System air operated valves at Byron Unit 2 in accordance with 10 CFR 50.55a(z)(2) until the 2A Containment Chiller is returned to operable status, but no later than July 19, 2024.
All other requirements in ASME OM Code for which an alternative or relief was not specifically requested and authorized or granted remain applicable.
This verbal authorization does not preclude the NRC staff from asking additional clarification questions regarding the proposed alternative while subsequently preparing the written safety evaluation.
Hearing Identifier:
NRR_DRMA Email Number:
2634 Mail Envelope Properties (MN2PR09MB49712DC1A49E350D78AB12B98BD62)
Subject:
Verbal Relief for Byron, Unit 2, Three Specific Air-operated Valves in the Essential Service Water System (L-2024-LLR-0042)
Sent Date:
6/26/2024 11:41:21 AM Received Date:
6/26/2024 11:41:00 AM From:
Joel Wiebe Created By:
Joel.Wiebe@nrc.gov Recipients:
"Zurawski, Lisa M:(Constellation Nuclear)" <lisa.zurawski@constellation.com>
Tracking Status: None Post Office:
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