ML20100N322
| ML20100N322 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 04/09/2020 |
| From: | Jennifer Tobin NRC/NRR/DORL/LPL1 |
| To: | Penfield R FirstEnergy Corp |
| Tobin J | |
| References | |
| EPID L-2020-LLR-0054 | |
| Download: ML20100N322 (4) | |
Text
From:
Tobin, Jennifer To:
rpenfield@firstenergycorp.com Cc:
Lashley, Phil H (EH); McCreary, Dave M (EH)
Subject:
Verbal Relief for Penetration Evaluation and Hot Leg Nozzles - Delivered 4/9/2020 at 10:00 am Date:
Thursday, April 09, 2020 10:21:00 AM Good morning Mr. Penfield, Please find below a written documentation of the verbal relief that NRC provided this morning (4/9/2020). This email will be made publicly available.
Participants:
Energy Harbor NRC Mark Manoleras Matt Mitchell Brandon Padgett Jim Danna Perry Seaman John Tsao Jeff Morgan Jenny Tobin Kathy Nevins Phil Lashley
Please contact me with questions or concerns.
Thanks!
-Jenny
VERBAL AUTHORIZATION BY THE OFFICE NUCLEAR REGULATION 10 CFR 50.55aREQUESTS2-TYP-4-RV-06AND 2-TYP-4-RV-07 ALTERNATE EXAMINATION OF HOT LEGDISSIMILAR METAL BUTTWELDSAND BOTTOM MOUNTED INSTRUMENTATIONPENETRATIONS BEAVER VALLEYPOWERSTATION, UNIT 2 ENERGY HARBOR NUCLEARCORPORATION DOCKET NO. 50-412 EPID L-2020-LLR-0053 AND L-2020-LLR-0054 APRIL9, 2020
Technical Evaluation read by Matthew Mitchell, Chief of the Piping and Head Penetration Branch, Office of Nuclear Reactor Regulation
By letter datedApril 3, 2020 (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML20093E657 and ML20094G936),Energy Harbor Nuclear Corporation(the licensee), requested alternativesto the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI,Code CasesN-722-1 andN-770-2 forBeaver ValleyPowerStation, Unit 2(Beaver Valley, Unit 2).
For pressurized water reactors,Title 10 of the Code of Federal Regulations (10 CFR) 50.55a,paragraph10 CFR 50.55a(g)(6)(ii)(E) mandatestheuseofASME Code Case N-722-1 toperformabare metal visualinspection of the hot leg Alloy 82/182 dissimilar metal butt welds every refueling outage andbottom mounted instrumentation (BMI)penetrations every other refueling outage.Paragraph10 CFR 50.55a(g)(6)(ii)(F)
mandatestheuseofASME Code Case N-770-2 toperformabare metal visualinspection ofunmitigatedhot legAlloy 82/182 dissimilar metal butt weldsevery refueling outage andavolumetric inspection everysecondrefueling outage.
The licensee submittedRequest 2-TYP-4-RV-06toeliminate thebare metal visual examinationin the units Spring 2020 refueling outage (2R21)for thethree dissimilar metal butt welds:2RCS-REV21-N-24, 2RCS-REV21-N-26, and 2RCS-REV21-N-28,whichjoin the reactor vesselnozzlesto the safe endsof the hot legs.Also, the licensee submitted Request 2-TYP-4-RV-07 to defer the bare metal visual examinationoftheunits reactor vesselBMI penetrationsfromtheSpring 2020refueling outagetotheFall 2021 refueling outage(2R22).
On March 13, 2020, the President of the United States declared a national emergency due to the spread and infectious nature of the Coronavirus-2019 (COVID-19) virus and resulting pandemic. The Centers for Disease Control and Prevention (CDC) recommends for social distancing by maintaining approximately six feet from other personnel to limit the spread of the virus. On March 28, 2020, the Governor of Pennsylvania issued a Stay-at-Home order for Beaver County and the surrounding counties of Allegheny and Butler.
The licensee stated that the above specified examinations require construction personnel to open hatches in the floor of the refueling cavity, install temporary lighting, remove neutron shield material, and remove insulation. Additional contract and onsite staff are required to perform radiological surveys and the weld examinations. Because of the rapid spread and infection rates of the virus, the licensee anticipates challenges to maintain staff levels throughout the outage and is requesting relief where appropriate to reduce necessary staff.
Therefore, to minimize theCOVID-19pandemicaffectingplant personnel, the licenseesubmitted these twoalternativerequests pursuant to 10 CFR 50.55a(z)(2) on the basis thatcomplying with theinspectionrequirementsof Code Cases N-722-1 and N-770-2would result in a hardship or unusual difficulty without a compensating increase in the level of quality and safety.The NRC staff determines that to minimize the plant personnel from COVID-19, the licensees hardship justification is acceptable.
Further, in regards to evaluating whether the request alternative provides for reasonable assurance of adequate protection, the NRC staff finds that the licensee haspreviouslyinspected the subject welds and BMIpenetrations in accordance withboth code casesand has not identifiedany indicationsin these components.The NRC staff notes that the material used in the subject welds and BMIpenetrationshassufficientfracture toughnesstoresistsuddencrack propagation. If a flaw does occurduring normal operation, the likely scenario is that theflaw will grow slowly tobecome 100percentthrough wallin a localized location, and aleak will occurrather than a catastrophic failure.The NRC staff finds that shouldaleakoccurin the subject components,thelicenseesintegrated leakage monitoring programcan detecta leak rateas low as0.1 gallons per minute(gpm).
The licensee stated that thereactor coolant system (RCS)Integrated Leakage Program includes the requirement to identify the leakage source and could include entering containment to identify the source.lfthe leakage is found and isolated, the licensee will re-perform an RCS leak rate calculation to confirm that the leakage has been addressed.
Depending on the source identified, a shutdown could be required in accordance
withLimiting Condition for Operation(LCO)3.4.13in the plant Technical Specifications which limits unidentified leakage to 1gpm.In addition, the licensee has implemented administrative limits to ensure that leakage will not challenge the 1gpmlimits.The licensee further stated that during operation, an increase in radiation levels within containment would be noted if there were significant leakage.
Based on industry operating experience, the NRC staff finds that a flaw that causes a leak rate of 0.1gpmwould be small and would not challenge structural integrity of either the subject welds or BMIpenetrations.
Thelicensee statedthatthe general area around and below the reactor vesselwill beexamined as part of the pressure test program walkdown during Mode 3 start upafter completion of the Spring 2020 refueling outage.The licenseefurtherstated that any leakage identified would be investigated to determine the source.The NRC staff notes that the licensees pressure testisconsistent withthe ASME Code,Section XI, IWA-5000which requires aVT-2 visual examination associated with thesystem leakage test of the Class 1 pressure-retaining components.The NRC staff notes that VT-2 visual examination is not as effective as the bare metal visual examination as required by N-722-1 and N-770-2 butis reasonablecompensatory measure.
The NRC staff findsreasonable assurance that structural integrity of the subject welds and BMIpenetrations will be maintained because (1)thesubject welds andBMIpenetrationshave notshownindicationsin the past inspections, (2)thelicensees integratedleakage monitoringprogram hasthe capability of detecting 0.1gpm, (3)the licensee has administrative leakage limits withassociated actionsto ensure leakagewillnotreach Technical Specification limits,(4)the fracture toughness of the materialwill resist uncontrollable flaw propagation, and (5) the licensee will perform a system leakage test at the end of Spring 2020 refueling outage.
Authorization read by JamesG.Danna, Chief of the Plant Licensing Branch I, Office of Nuclear Reactor Regulation
As Chief of the Plant Licensing Branch I, Office of Nuclear Reactor Regulation, I agree with the conclusions of the Piping and Head Penetration Branch.
The NRC staff concludes that Requests 2-TYP-4-RV-06 and 2-TYP-4-RV-07 will provide reasonable assurance of structural integrity of subject hot leg welds and BMI penetrations until the next scheduled bare metal visual examinations to be performed in the Fall of 2021. The NRC staff finds that complying with the requirements of the ASME Code,Section XI, Code Cases N-722-1 and N-770-2 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 the regulatory requirements set forth in 10 CFR 50.55a(z)(2). Therefore, effective April 9, 2020, the NRC authorizes the use of Requests 2-TYP-4-RV-06 and 2-TYP-4-RV-07 at Beaver Valley, Unit 2 until the next scheduled refueling outage 2R22 in the Fall of 2021.
All other requirements in ASME Code,Section XI,10 CFR 50.55a(g)(6)(ii)(E) and 10 CFR 50.55a(g)(6)(ii)(F)for which relief was not specifically requested and approved in thesetworequestsremain applicable, including third-party review by the Authorized Nuclear Inservice Inspector.
This verbal authorization does not preclude the NRC staff from asking additional clarification questions regarding the proposedalternativewhile subsequently preparing the written safety evaluation.