CP-202000311, Notification of Deviation from Electric Power Research Institute MRP 2018-027, NEI 03-08 Needed Inspection Guidance for PWR CRDM Thermal Sleeve Wear, Superseded by PWROG-16003-P, Evaluation of .

Notification of Deviation from Electric Power Research Institute MRP 2018-027, NEI 03-08 Needed Inspection Guidance for PWR CRDM Thermal Sleeve Wear, Superseded by PWROG-16003-P, Evaluation of .

ML20132A308
Person / Time
Site:	Comanche Peak
Issue date:	05/11/2020
From:	Sewell S Luminant, Vistra Operations Company
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CP-202000311, NEI 03-08, TXX-20041
Download: ML20132A308 (6)

Text

Steven K. Sewell Comanche Peak Senior Director, Nuclear Power Plant Engineering & Regulatory Affairs (Vistra Operations Company LLC)

P.O. Box 1002 6322 North FM 56 Glen Rose, TX 76043 T 254.897.6113 CP-202000311 TXX-20041 May 11, 2020 U. S. Nuclear Regulatory Commission Ref NEI 03-08 ATTN: Document Control Desk 10 CFR50.4 Washington, DC 20555-0001

Subject:

Comanche Peak Nuclear Power Plant (CPNPP), Docket No. 50-446 Notification of Deviation from Electric Power Research Institute (EPRI) MRP 2018-027, NEI 03-08 Needed Inspection Guidance for PWR CRDM Thermal Sleeve Wear, superseded by PWROG-16003-P, Evaluation of Potential Thermal Sleeve Flange Wear, Revision 2 dated May of 2019

Dear Sir of Madam:

Vistra Operations Company LLC (Vistra OpCo) is providing notification that Comanche Peak Nuclear Power Plant (CPNPP) Unit 2, has processed a deviation from a Nuclear Energy Institute (NEI) 03-08 Guideline for the Management of Materials Issues, Revision 3 needed interim inspection guidance for PWR CRDM Thermal Sleeve Wear, with appropriate justification and documentation.

Reactor closure head PWR control rod drive mechanism (CRDM) Thermal Sleeve flange wear measurements are a Needed requirement specified in MRP 2018-027, superseded by PWROG-16003-P, Evaluation of Potential Thermal Sleeve Flange Wear, Revision 2 dated May of 2019. This requirement initiated from Westinghouse issued 10CFR Part 21 report and NSAL-18-1 which provides the recommendations for the affected plants.

NEI 03-08 allows deviation from Needed elements with the appropriate justification and documentation. The deviation was documented in accordance with the CPNPP corrective action program and approved by the appropriate levels of Vistra OpCo Management. The attachment with this letter provides a summary of the evaluation and justification for the deviation.

The Program Director, PWR Owners Group Program Management Office was notified on April 28, 2020 of the aforementioned needed deviation.

This notification is provided for information only. No approval or action is requested.

TXX-20041 Page 2 of 2 This communication contains no new commitments regarding CPNPP Unit 2.

Should you have any questions, please contact Jim Barnette at (254) 897-5866 or James.Barnettte@luminant.com.

Sincerely,

Attachment:

Summary - Deviation Evaluation, CRDM Thermal Sleeve Wear Measurement Requirement c (email) - Scott Morris, Region IV [Scott.Morris@nrc.gov]

Dennis Galvin, NRR [Dennis.Galvin@nrc.gov]

John Ellegood, Senior Resident Inspector, CPNPP Uohn.Ellegood@nrc.gov]

Neil Day, Resident Inspector, CPNPP [Neil.Day@nrc.gov]

Matthew Mitchell, Chief, Piping and Head Penetration Branch

[Matthew.Mitchell@nrc.gov]

Attachment to TXX-20041 COMANCHE PEAK NUCLEAR POWER PLANT Summary - Deviation Evaluation, CRDM Thermal Sleeve Wear Measurement Requirement

TXX-20041 Page 2 of 4 Summary - Deviation Evaluation, CRDM Thermal Sleeve Wear Measurement Requirement Utility: Vistra Operations Company LLC (Vistra OpCo)

Applicable Site and Unit No.: Comanche Peak Nuclear Power Plant (CPNPP), Unit 2 Utility Contact(s): Tom Crippes - Engineering Programs; Chung Tran - Engineering Programs Manager Issue Program (IP) activity or document:

x NEI 03-08 Needed Inspection Guidance for PWR CRDM Thermal Sleeve Wear, August 31, 2018 (MRP 2018-027), superseded by PWROG-16003-P, Evaluation of Potential Thermal Sleeve Flange Wear, Revision 2 dated May of 2019.

CPNPP Unit 2 is deferring the reactor head Thermal Sleeve Flange wear measurements for one additional refueling outage from Spring of 2020 (2RF18) to Fall of 2021 (2RF19) with no compromise on nuclear safety. This is a deviation from the NEI 03-08, (Guideline for the Management of Materials Issues) Needed requirement specified in MRP 2018-027, (Interim Guidance to Address Wear of Thermal Sleeve Flanges per Notification MRP 2018-010) as a response to Thermal Sleeve Emergent Issue and NSAL-18-1, (Thermal Sleeve Flange Wear Leads to Stuck Control Rod), superseded by PWROG-16003-P, Evaluation of Potential Thermal Sleeve Flange Wear, Revision 2 dated May of 2019.

The bases for the need to deviate from the above guidance is due to the COVID-19 declaration of emergency pursuant to the Stafford Act on March 13, 2020 made by the U.S Federal Government. The U.S. Center for Disease Control (CDC) has determined that COVID-19 poses a serious public health risk. The CDC has identified many U.S.

States reporting community spread of COVID-19 with the anticipation of conditions worsening over the coming weeks.

In response to the COVID-19 Pandemic, Vistra Operations Company LLC (Vistra OpCo) has established the following guidelines and restrictions at Comanche Peak Nuclear Power Plant (CPNPP):

1. Employees who do not have a critical need to be at CPNPP facilities must work remotely.

2. Employees who must work from a CPNPP facility are to practice strict social distancing.

3. 2RF18 Outage scope shall be reduced to limit the number of supporting contract personnel.

TXX-20041 Page 3 of 4 These guidelines and restrictions were established to reduce the potential of inadvertently spreading the COVID-19 virus to CPNPP personnel and the surrounding communities from outside contractors who perform specialized work regarding thermal sleeve flange wear measurements and inspections at CPNPP. Also, due to recent travel restrictions and quarantine requirements imposed by both the U.S.

Government and the State of Texas, the availability of outside contractors to provide specialized services may be limited.

Many of the planned 2RF18 Outage activities have been postponed until future outages based on these guidelines and restrictions. Performing thermal sleeve flange wear measurements during 2RF18 for CPNPP Unit 2 could potentially challenge the site on controlling the spread of the virus without a compensating increase in level of the quality or safety during the current COVID-19 pandemic.

Moving the thermal sleeve inspection to 2RF19 only slightly exceeds the specified range set forth in NSAL 18-1 in which the requirement to measure the thermal sleeve flange wear is required. At the time of 2RF18, CPNPP Unit 2 will be in the 20 - 25 effective full power year (EFPY) range that requires the flange wear measurements to be completed. It is not expected that CPNPP Unit 2 will exceed this range of EFPY until approximately March 3, 2021 and will only be at 25.5129 EFPY by 2RF19. A majority of the units within the industry that have reported issues with their thermal sleeves were at an EFPY of operation at the time of discovery that were beyond the estimated EFPY that Unit 2 will be at by the time of 2RF19.

Recently CPNPP has completed removal of the unit 2 reactor vessel closure head with no reported signs of thermal sleeve separation or wear marks on the top of the control rod guide tubes that would indicate a thermal sleeve has separated and is sitting on top of the guide tubes causing a wear ring. In addition, to date, no issues or deviations have been raised regarding control rod drop times performed for Unit 2 at CPNPP that would indicate interference with the movement of the control rods. Therefore, at this time there is no evidence at CPNPP Unit 2 that the ability of the control rods to perform their designated safety function is degraded in any way.

Furthermore, OPT-106B, Control Rod Exercise test performed satisfies shutdown and control rod operability testing for Technical Specification Surveillance, SR 3.1.4.2 on a quarterly basis and ETP-106, Monthly Rod Cluster Control Assembly (RCCA)

Repositioning Procedure performs the RCCA repositioning in accordance with the control rod repositioning schedule on a monthly basis. Both of these activities performed during last cycle validate that the CDRMs have been capable of performing their design function.

TXX-20041 Page 4 of 4 Deferring the thermal sleeve flange wear measurement inspection from the Spring of 2020 (2RF18) to the fall of 2021 (2RF19) outage will not adversely impact the function of the CRDMs and/or associated thermal sleeves. Nor will deferring the wear measurements result in a reduction in plant nuclear safety based on review of the known most current data and the extent of wear based on wear distribution from the measured plants and current shutdown control rod drop surveillance testing data. In the current pandemic environment, performing the recommended wear measurements would result in an increased risk of virus exposure to plant personnel and a reduction in occupational health and safety without a compensating benefit. Therefore, this one-time deviation from the interim guidance is justified without a compensating increase in level of quality or nuclear safety during the current COVID-19 pandemic.