ML19326A315
| ML19326A315 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs, Dresden, Peach Bottom, Nine Mile Point, Byron, Braidwood, Limerick, Ginna, Clinton, Quad Cities, FitzPatrick, LaSalle, Crane  |
| Issue date: | 12/03/2019 |
| From: | Blake Purnell Plant Licensing Branch III |
| To: | |
| Purnell B | |
| Shared Package | |
| ML19326A326 | List: |
| References | |
| EPID L-2019-LRM-0075 | |
| Download: ML19326A315 (5) | |
Text
December 3, 2019 LICENSEE:
EXELON GENERATION COMPANY, LLC FACILITIES: BRAIDWOOD STATION, UNITS 1 AND 2; CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 AND 2; CLINTON POWER STATION, UNIT NO. 1; LIMERICK GENERATING STATION, UNITS 1 AND 2; NINE MILE POINT NUCLEAR STATION, UNITS 1 AND 2; PEACH BOTTOM ATOMIC POWER STATION, UNITS 2 AND 3; AND R. E. GINNA NUCLEAR POWER PLANT
SUBJECT:
SUMMARY
OF NOVEMBER 18, 2019, MEETING WITH EXELON GENERATION COMPANY, LLC REGARDING A PLANNED REQUEST FOR AN ALTERANTIVE TO SUPPLEMENTAL VALVE POSITION INDICATION TESTING REQUIREMENTS (EPID L-2019-LRM-0075)
On November 18, 2019, a Category 1 public meeting was held between the U.S. Nuclear Regulatory Commission (NRC) staff and representatives of Exelon Generation Company, LLC (Exelon, the licensee). The purpose of the meeting was to discuss a proposed alternative to the requirements in Title 10 of the Code of Federal Regulations (10 CFR) Section 50.55a, Codes and standards, for supplemental position indication (SPI) testing of valves. The meeting notice and agenda are available in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML19308A051. A copy of Exelons presentation is available in ADAMS at Accession No. ML19317C995. A list of attendees is enclosed.
The proposed alternative will be for the Exelon plants which are currently using, or will be using in 2020, the 2012 Edition of the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code). The ASME OM Code requires SPI testing of valves to be performed once every 2 years. In addition, 10 CFR 50.55a(b)(3)(xi) requires:
When implementing ASME OM Code, 2012 Edition, Subsection ISTC-3700, Position Verification Testing, licensees shall verify that valve operation is accurately indicated by supplementing valve position indicating lights with other indications, such as flow meters or other suitable instrumentation, to provide assurance of proper obturator position.
Exelon is planning on submitting this alternative as a fleet request in December 2019. For plants that transition to the 2012 Edition of the ASME OM Code after 2020, Exelon would request a similar alternative on an individual plant bases with other relief requests that are typically submitted before the start of the next 10-year in-service testing interval.
The proposed alternative would not apply to active motor-operated valves tested in accordance with the Mandatory Appendix III, Preservice and Inservice Testing of Active Electric Motor Operated Valve Assemblies in Light-Water Reactor Power Plants, of the ASME OM Code. In addition, Exelon stated that the proposed alternative would not apply to Anchor Darling double-disc gate valves. The NRC staff stated that it would better to exclude valves with threaded connections, rather than explicitly excluding Anchor Darling valves.
Exelon stated that the SPI requirements or frequency would be adjusted using either component risk ranking results or crediting seat leakage testing to prove closure following NRC-approved performance-based frequencies. Under the latter method, the alternative test frequency would be consistent with the test frequencies in Appendix J, Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors, to 10 CFR Part 50.
Under the risk ranking process, Exelon would only relax the SPI testing requirement or frequency for specific valves if the risk consequences or susceptibility to stem-to-disc separation are acceptably low and one of the predefined criteria for hardship are met. Exelon further described how it would determine risk ranking and susceptibility to failure. The NRC staff stated that Exelon should consider operational experience which indicates that most issues have been with valves exposed to untreated water or in high-energy systems.
Exelon confirmed that it would not extend the currently required SPI test interval (i.e., once every 2 years) for high-risk valves that are susceptible to failure. The NRC staff noted that it would consider extension of the SPI test interval for high-risk valves that have a low susceptibility to failure.
Exelon also provided examples of the hardship criteria. Exelon plans to submit its alternative request in accordance with 10 CFR 50.55a(z)(2). This regulation allows the NRC staff to authorize an alternative to 10 CFR 50.55a if the licensee demonstrates that compliance with specific requirements in 10 CFR 50.55a would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. The staff stated that it will need to seek legal advice to determine if 50.55a(z)(2) would allow approval of predetermined hardship criteria or if the licensee must identify the specific hardship for each valve as part of the application. The staff further stated that requesting the alternative in accordance with 50.55a(z)(1), which requires the license to demonstrate the alternative provides an acceptable level of quality and safety, may be a better approach.
The NRC staff also noted that there is a draft code case that would provide similar relief if it is ever finalized and endorsed by the ASME OM Code Committee. One commenter from industry noted that it may be beneficial to finalize this code case.
Public meeting feedback forms were not received. Please direct any inquiries to me at 301-415-1380, or Blake.Purnell@nrc.gov.
/RA/
Blake Purnell, Project Manager Plant Licensing Branch III Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. STN 50-456, STN 50-457, 50-317, 50-318, 50-461, 50-352, 50-353, 50-220, 50-410, 50-277, 50-278, and 50-244
Enclosure:
List of Attendees cc: Listserv
ML19326A315 (Summary)
ML19326A326 (Pkg.)
- via e-mail NRR-106 OFFICE NRR/DORL/LPL3/PM NRR/DORL/LPL3/LA NRR/DORL/LPL3/BC NRR/DORL/LPL3/PM NAME BPurnell SRohrer NSalgado BPurnell DATE 12/2/2019 12/2/2019 12/3/2019 12/3/2019
Enclosure LIST OF ATTENDEES NOVEMBER 18, 2019, MEETING WITH EXELON GENERATION COMPANY, LLC Name Affiliation Blake Purnell NRC Michael Farnan NRC Stewart Bailey NRC Ryan Sprengel Exelon Mark DiRado Exelon William Reynolds Exelon Glenn Weiss Exelon Marcellus Ruff Exelon Carl McIlheran Exelon Keven Meyers Exelon David Neff Exelon Jason Taken Exelon Todd Cervini Exelon Brandon Shultz Exelon Lisa Zurawski Exelon Dwi Murray Exelon Ken Nicely Exelon Richard Gropp Exelon Rick Villar Exelon Thomas Loomis Exelon Brad Fuller Pennsylvania Department of Environmental Protection