CP-202300207, Revision to Comanche Peak Nuclear Power Plant'S Response to Notice of Violation (NOV) 05000445/2021011-05

Revision to Comanche Peak Nuclear Power Plant'S Response to Notice of Violation (NOV)05000445/2021011-05

ML23145A291
Person / Time
Site:	Comanche Peak
Issue date:	05/25/2023
From:	John Lloyd Luminant, Vistra Operations Company
To:	NRC Region 4, Document Control Desk
References
CP-202300207, TXX-23029, IR 2021011 IR 2021011-05
Download: ML23145A291 (1)

Text

Jay Lloyd Comanche Peak Senior Director, Nuclear Power Plant Engineering and Regulatory Affairs (Vistra Operations Company LLC)

P.O. Box 1002 6322 North FM 56 Glen Rose, TX 76043 T 254.897.6113 CP-202300207 TXX-23029 May 25, 2023 U. S. Nuclear Regulatory Commission Ref 10CFR2.201 ATTN: Document Control Desk Washington, DC 20555-0001

Subject:

Comanche Peak Nuclear Power Plant Docket Nos. 50-445 and 50-446 Revision to Comanche Peak Nuclear Power Plant's Response to Notice of Violation (NOV)05000445/2021011-05

References:

1. NRC Letter from Vincent Gaddy to Ken Peters dated May 6, 2021, "Comanche Peak Nuclear Power Plant, Units 1 And 2 - Design Basis Assurance Inspection (Teams) Inspection Report 05000445/2021011 And 05000446/2021011 And Notice Of Violation" (ADAMS Accession Number ML21124A130)

2. Luminant Letter from Thomas P. McCool to U.S. NRC dated June 3, 2021, "Comanche Peak Nuclear Power Plant (CPNPP) Docket Nos. 50-445 and 50-446 - Reply To A Notice Of Violation" (ADAMS Accession Number ML21154A186)

Dear Sir or Madam:

Pursuant to 10CFR2.201(a)(3), Vistra Operations Company LLC (Vistra OpCo) has created this letter to inform the NRC that the date when full compliance will be achieved has been extended, please see the revised commitment below for Comanche Peak Nuclear Power Plant Units 1 and 2:

Commitment Original Description Revised Description No.

In accordance with the CPNPP Corrective In accordance with the CPNPP Corrective Action Program, non-1E loads on UPS panels Action Program, a plant modification will be will be reviewed by December 3, 2021, to implemented to replace the required fuses and determine if a basis can be provided that would fuse holders, to ensure that the Class 1E assure the non-1E load circuit's integrity to inverters will continue to operate reliably 21-344702 withstand a DBE without a short or short to when subjected to the effects of electrical faults ground, and can remain to be fed from the panel that could be postulated to occur at non-Class and coordination of these circuits will not be a loads, due to a lack of seismic qualification of concern. If this review concludes that a basis the loads, during and after a design basis loss-cannot be provided, then a plant modification of-offsite power and seismic event. This will will be implemented by June 1, 2023. be implemented by December 1, 2023.

The evaluation was performed, and it was determined that a plant modification was necessary to restore CPNPP to compliance. The reason this extension is necessary is due to the need to wire trace downstream all activities to ensure that any impacts to Operations are well understood and that the risk is mitigated.

CPNPP does not have the resources to complete this, as well as the Unit 2 Refueling Outage, by the previous due date of June 1, 2023.

The risk of extending this commitment is minimal due to the non-Class 1E (N1E) components fed from these panels being installed in safety related panels. The N1E components in these safety related panels do conform to seismic 2/1 requirement. With this configuration the failure of these N1E components during a seismic event is considered highly unlikely.

Should you have any questions, please contact Ryan Sexton at (979) 292-5064 or ryan.sexton@vistracorp.com.

Sincerely, Jay Lloyd (May 25, 2023 11:45 CDT)

Jay Lloyd

Attachment:

1. Revision to Response for Notice of Violation 05000445/2021011-05 c (email): Robert Lewis, Region IV [Robert.Lewis@nrc.gov]

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

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

David Nani, Resident Inspector, CPNPP [David.Nani@nrc.gov]

Attachment 1 Revision to Response for Notice of Violation 05000445/2021011-05

NOTICE OF VIOLATION 05000445/2021011-05

SUMMARY

Title 10 CFR Part 50, Appendix B, Criterion III requires in part, that applicable regulatory requirements and design basis are correctly translated into specifications, drawings, procedures, and instructions.

Contrary to the above, from June 18, 2015, to March 25, 2021, the licensee did not assure that applicable regulatory requirements and design basis are correctly translated into specifications, drawings, procedures, and instructions. Specifically, the licensee failed to verify or check the adequacy of the design by performing an analysis or test that demonstrated that the Class 1E inverters would continue to operate reliably when subjected to the effects of electrical faults that could be postulated to occur at non-Class loads, due to a lack of seismic qualification of the loads, during and after a design basis loss-of-offsite power and seismic event.

RESPONSE TO NOTICE OF VIOLATION 05000445 / 2021011-05

1. Reason for the Violation During the 2015 NRC Component Design Basis inspection at Comanche Peak Nuclear Power Plant (CPNPP), the inspectors identified that CPNPP failed to verify or check the adequacy of the design by performing an analysis or test that demonstrated the Class 1E inverters would continue to operate reliably when subjected to the effects of electrical faults that could be postulated to occur at non-class loads, due to a lack of seismic qualification of the loads, during and after a design basis loss of offsite power and seismic event. Condition Report (CR) 2015-005530 was issued to address this Finding. This violation occurred because CR 2015-005530 was not given a high enough priority for it to be completed in a timely manner.

2. Corrective Steps That Have Been Taken and the Results Achieved An extent of condition review was completed. The affected UPS system panels with non-class 1E loads have been identified. An evaluation was performed for all identified non-class 1E loads (Calculation EE-1E-UPS-N1E-SC-EVAL). Fault clearing time for N1E circuits, not coordinated with acceptable loss of voltage time for their panels, are listed in the calculation. The calculation evaluates a replacement fuse for each circuit to provide coordination with acceptable loss of voltage time for their panel. A design change to replace these fuses, FDA-2022-000010-01, will ensure coordination of all N1E circuit load faults with acceptable loss of voltage time for their panel to provide uninterruptable power for safety related loads fed from the panels.

3. Corrective Steps That Will Be Taken CPNPP will implement the design change FDA-2022-000010-01 by December 1, 2023.

4. Date When Full Compliance Will Be Achieved Vistra OpCo will be in full compliance by December 1, 2023