ML21109A209
| ML21109A209 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 04/19/2021 |
| From: | David Gudger Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML21109A209 (6) | |
Text
200 Exelon Way Kennett Square, PA 19348 www.exeloncorp.com 10 CFR 50.55a April 19, 2021 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 R. E. Ginna Nuclear Power Plant Renewed Facility Operating License Nos. DPR-18 NRC Docket No. 50-244
Subject:
Additional Information - One-Time Interval Extension for Supplemental Position Indication Testing
Reference:
Letter from D. Gudger (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, One-Time Interval Extension for Supplemental Position Indication Testing, dated April 12, 2021 In the Referenced letter, Exelon Generation Company, LLC (Exelon), requested NRC approval of a proposed relief request associated with the Inservice Testing (IST) Program for the R. E. Ginna Nuclear Power Plant. This request proposes a one-time extension to the 2-year Supplemental Position Indication (SPI) testing frequency for fifteen IST program valves.
Attached is additional clarification to the Referenced submittal. Revisions to the relief request are identified with revision bars.
There are no regulatory commitments contained in this letter.
If you have any questions, please contact Tom Loomis at 610-765-5510.
Respectfully, David T. Gudger Senior Manager - Licensing and Regulatory Affairs Exelon Generation Company, LLC
Attachment:
Additional Information - Relief Request GR One-Time Interval Extension for SPI Testing cc:
Regional Administrator - NRC Region I NRC Senior Resident Inspector - Ginna NRC Project Manager - Ginna
ATTACHMENT Additional Information - Relief Request GR One-Time Interval Extension for Supplemental Position Indication Testing
10 CFR 50.55a Relief Request: GR-03 Revision 0 (Page 1 of 4)
Request for Relief GR-03 One-Time Interval Extension for Supplemental Position Indication Testing In Accordance with 10 CFR 50.55a(z)(2)
- 1. ASME Code Component(s) Affected:
Pneumatically operated and motor operated valves with remote position indications were not verified in the open and/or closed position using a supplemental indication during the Ginna Nuclear Power Plant refueling outage conducted in April 2020. This includes the following valves. The table below reflects the successful open (O) and closed (C) tests, or no SPI test performed (--):
Valve ID Description Code Class Category Type Test Expiration SPI Test Performed 310 Excess Letdown Loop A Cold to Heat Exchanger Valve 1
B AOV 5/2/2021 C
371 Letdown Isolation Valve Residual Heat Removal to Non-Regenerative Heat Exchanger 2
A AOV 5/2/2021 O
386 Reactor Coolant Pump A and B Seal Bypass Valve 2
B AOV 5/2/2021 5392 Instrument Air to Containment Isolation Valve 2
A AOV 5/2/2021 O
835A Safety Injection Accumulator A Fill Valve 2
B AOV 5/2/2021 C
835B Safety Injection Accumulator B Fill Valve 2
B AOV 5/2/2021 C
839A Safety Injection Accumulator A Test Valve 2
B AOV 5/2/2021 C
840A Safety Injection Accumulator B Test Valve 2
B AOV 5/2/2021 C
844A Safety Injection Accumulator A Drain Valve 2
B AOV 5/2/2021 844B Safety Injection Accumulator B Drain Valve 2
B AOV 5/2/2021 875A Upper Containment Spray Charcoal Filter Dousing Valve 2
B MOV 5/6/2021 875B Upper Containment Spray Charcoal Filter Dousing Valve 2
B MOV 5/6/2021 876A Lower Containment Spray Charcoal Filter Dousing Valve 2
B MOV 5/6/2021 876B Lower Containment Spray Charcoal Filter Dousing Valve 2
B MOV 5/6/2021 966A Pressurizer Steam Space Sample Containment Isolation Valve 2
A AOV 4/28/2021 C
10 CFR 50.55a Relief Request: GR-03 Revision 0 (Page 2 of 4)
American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code), 2012 Edition with no Addenda.
3. Applicable Code Requirements
ISTC-3700, Position Verification Testing, states: "Valves with remote position indicators shall be observed locally at least once every 2 years to verify that valve operation is accurately indicated. Where practicable, this local observation should be supplemented by other indications such as use of flow meters or other suitable instrumentation to verify obturator position. These observations need not be concurrent. Where local observation is not possible, other indications shall be used for verification of valve operation.
10 CFR 50.55a(b)(3)(xi) OM condition: Valve Position Indication states: When implementing paragraph ISTC-3700, "Position Verification Testing," in the ASME OM Code, 2012 Edition through the latest edition and addenda of the ASME OM Code incorporated by reference in paragraph (a)(1)(iv) of this section, 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 for valves with remote position indication within the scope of Subsection ISTC including its mandatory appendices and their verification methods and frequencies.
As required by 10 CFR 50.55a(b)(3)(xi), ISTC-3700 requirements became applicable on January 1, 2020 when the R. E. Ginna Nuclear Power Plant (Ginna) Inservice Testing (IST)
Program was updated to the 2012 Edition of the ASME OM Code.
- 4. Reason for Request:
Pursuant to 10 CFR 50.55a, Codes and standards, paragraph (z)(2), compliance with the requirements of ISTC-3700 will create undue hardship without a compensating increase in the level of quality or safety. Compliance will require a plant shutdown to perform a SPI for the valves listed in Section 2.
The most-limiting Supplemental Position Indication (SPI) testing interval for these valves ends on April 28, 2021, based on the 2-year interval that came into effect on January 1, 2020 and considering the use of the 6-month interval extension allowed by ASME OM Code Case OMN-20, Inservice Test Frequency. The position verification with SPI requires the valves to be exercised in the open and closed direction and the valves position verified by other indications such as use of flow meters or other suitable instrumentation to verify obturator position. The timing for implementation was not clear; therefore, several position verification tests were performed that were not supplemented with alternate indication to demonstrate obturator position.
This relief request proposes a one-time interval extension of eight months (December 28, 2021) which will allow testing during the next refueling outage which is scheduled to begin October 4, 2021. This extension will avoid a forced plant shutdown to achieve refueling conditions to permit safely stroking the identified valves.
10 CFR 50.55a Relief Request: GR-03 Revision 0 (Page 3 of 4)
- 5. Proposed Alternative and Basis for Use:
As a proposed alternative to the 2-year SPI testing frequency required by ISTC-3700, this relief request proposes a one-time interval extension of eight months (December 28, 2021) which will allow testing during the next refueling outage which is scheduled to begin October 4, 2021. The listing of valves provided in Section 2 have satisfactorily passed their IST examinations for the past 10 years.
AOV-310, AOV-835A, AOV-835B, AOV-839A and AOV-840A are passive valves that are normally closed with a safety function in the closed direction only. AOV-310, AOV-835A and AOV-835B were verified to be closed on 4/10/2020 by serving as a boundary valve and holding pressure during leak rate testing of other valves. AOV-839A and AOV-840A were verified to be closed on 5/6/2020 by isolating safety injection flow during testing. SPI relief for the open position is being sought for these valves.
Open verification has been identified for AOV-371 by verifying CVCS flow during normal operation for the current interval. AOV-5392 is an instrument air supply valve and is proven to be open by verification of actuator performance of downstream air operated valves using this supply line for the current interval. Both of these valves had 0 SCCM leakage in their most recent leak rate testing performed 10/30/2015 for AOV-371 and 10/26/2018 for AOV-5392. Previous leak rate tests were prior to this interval. SPI relief for the closed position is being sought for these valves.
AOV-386 was verified to be closed on 5/11/2014 (the previous interval) by serving as a boundary valve and holding pressure during leak rate testing of another valve. AOV-844A and AOV-844B are accumulator drain valves that are verified to be closed by the accumulators maintaining water level during normal operations. Relief is being sought for these valves to allow quantifiable SPI testing to be performed in the upcoming outage.
MOV-875A, MOV-875B, MOV-876A, and MOV-876B are verified to be closed by the ability to maintain water level in the containment spray headers. SPI relief for the open and closed position is being sought for these valves.
AOV-966A was successfully Appendix J leak rate tested to demonstrate closure on 10/20/2020. SPI relief for the open position is being sought for this valve.
Any component degradation identified prior to the next outage will be evaluated per the Corrective Action Program for operability concerns and compliance with the IST Program and Technical Specifications.
The identified valves have demonstrated exceptional performance and reliability. The subject valves have no history of stem-disc separation. This was confirmed by an internal maintenance history search and by an INPO Industry Reporting Information System (IRIS) search for each valve make and model and review of EPRI Technical Report 3002019621 (Reference 1). The historical performance provides assurance of the valves capabilities to perform their design function(s) within the eight-month SPI interval extension. The past and current performance of each identified valve and the one-time interval extension bounded by test frequencies in existing regulations provide an acceptable level of quality and safety.
10 CFR 50.55a Relief Request: GR-03 Revision 0 (Page 4 of 4)
- 6. Duration of Proposed Alternative:
The proposed alternative is a one-time interval extension of eight months for the Ginna SPI testing of the identified valves, with an end date of December 28, 2021.
- 7. Precedent:
None
- 8.
References:
- 1. EPRI Technical Report 3002019621, Susceptibility of Valve Applications to Failure of the Stem-to-Disk Connection