NOC-AE-230039, Docket Nos. Stn 50-498, Stn 50-499 - Reply to a Notice of Violation, NRC Inspection Report 05000498/2023003 and 05000499/2023003

Docket Nos. Stn 50-498, Stn 50-499 - Reply to a Notice of Violation, NRC Inspection Report 05000498/2023003 and 05000499/2023003

ML23346A255
Person / Time
Site:	South Texas
Issue date:	12/12/2023
From:	Tomlinson J South Texas
To:	Office of Nuclear Reactor Regulation, NRC Region 4, Document Control Desk
References
NOC-AE-23003999, STI: 35538383, IR 2023003
Download: ML23346A255 (1)

Text

December 12, 2023 NOC-AE-23003999 File No.: G25 10 CFR 2.201 STI: 35538383 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 South Texas Project Units 1 and 2 Docket Nos. STN 50-498, STN 50-499 Reply to a Notice of Violation, NRC Inspection Report 05000498/2023003 and 05000499/2023003

References:

NRC Letter, South Texas Project Electric Generating Station, Units 1 and 2 -

Integrated Inspection Report 05000498/2023003 and 05000499/2023003, and Notice of Violation dated November 13, 2023, (AE-NOC-23003389)

(ML23310A228).

Pursuant to the provisions of 10 CFR 2.201, STP Nuclear Operating Company (STPNOC) herein provides a reply to the NRC Notice of Violation (NOV) contained in the above referenced letter. See the attachment for STPNOCs reply.

Corrective actions identified in the attachment will be tracked and implemented in accordance with the STP Corrective Action Program.

There are no regulatory commitments in this letter.

If there are any questions about this report, please contact Chris Warren at (361) 972-7293 or me at (361) 972-8945.

Jason R. Tomlinson Site Vice President

Attachment:

Reply to a Notice of Violation, NRC Inspection Report 05000498/2023003 and 050004999/2023003 Jason R Tomlinson Digitally signed by Jason R Tomlinson Date: 2023.12.12 15:11:19 -06'00'

NOC-AE-23003999 Page 2 of 2 cc:

Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 1600 E. Lamar Boulevard Arlington, TX 76011-4511 Dennis Galvin Project Manager U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Division of Operating Reactor Licensing Licensing Project Branch 4 Leanne Flores Senior Resident Inspector, South Texas Project U.S. Nuclear Regulatory Commission R4Enforcement@nrc.gov

NOC-AE-23003999 Attachment Page 1 of 2 Reply to a Notice of Violation, NRC Inspection Report 05000498/2023003 and 05000499/2023003 Restatement of Violation:

During an NRC inspection conducted from July 1 through September 30, 2023, a violation of NRC requirements was identified. In accordance with the NRC Enforcement Policy, the violation is listed below:

10 CFR Part 50, Appendix B, Criterion XVI requires, in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, and nonconformances are promptly identified and corrected.

Contrary to the above, from November 2021 to September 30, 2023, the licensee failed to assure that conditions adverse to quality, such as failures, malfunctions, and nonconformances were promptly identified and corrected. Specifically, the licensee failed to correct a condition adverse to quality associated with the 1B and 2C essential cooling water expansion joint tolerances. The expansion joint tie rod nut gap settings were not set to comply with design documentation due to incorrect work instructions.

The violation is associated with a Green significance determination process finding.

Reason for the Violation:

STPNOC initially corrected the Essential Cooling Water (ECW) expansion joint gap tolerance issue by performing corrective maintenance to set the stop nuts at the specified measurement per approved work instructions. The corrective actions were not successful because the work instructions did not correctly identify the design configuration gap of the stop nuts and the method used to secure the stop nuts (staking) did not ensure that the stop nuts would remain in the design configuration position during system operation.

STPNOC used procedure 0PGP03-ZX-0002B, Station Cause Analysis Program, and identified the following three causes of the event that resulted in the violation:

1. Staking of stop nuts are not an effective method to maintain the 1/4 gap.

a.

The staked bolt threads may allow the stop nut to back off before encountering the bolts staked threads before preventing further movement.

b.

The 1/4 space between the tie plate and the stop nut does not allow sufficient space to stake the bolt threads to prevent the stop nut from traveling towards the tie rod plate.

2. Ineffective monitoring and questioning attitude by engineering to address repeat issues across multiple trains that affected a safety-related component that did not affect Operability or Maintenance Rule Functionality.

3. Ineffective work order planning to ensure technical accuracy of work products.

NOC-AE-23003999 Attachment Page 2 of 2 Corrective Steps Taken and Results Achieved:

STPNOC has completed corrective maintenance and restored the subject ECW expansion joint tie rod nuts to design configuration with corrected work instructions. This action was performed for all three ECW trains for each Unit.

Corrective Steps That Will Be Taken:

STPNOC will take the following corrective steps to further address this issue:

1. Update 0PMP04-EW-0001A, Essential Cooling Water Pump Maintenance (Product-Lubricated Bearing Design), Step 5.12.8.2 to include on the expansion joint/tie rod configuration figure the inlet and outlet.

2. Revise WCG-0003, Planners Guide, Step 5.5.1.3.1 to include that an engineering review is required when an extent of condition review on safety related components has resulted in multiple work orders to address the same issue.

3. Engineering to develop a monitoring plan to periodically check the required expansion joint tie rod 1/4 gap. This may be sunset at the discretion of management after a minimum period of nine months if the implemented corrective actions are successful in maintaining the stop nuts in the design configuration.

4. Evaluate and implement alternative means to secure the expansion/compression stop nuts. Examples include Loctite or a set screw through the stop nut.

5. Develop and distribute a lessons learned for this event and discuss the importance of monitoring design compliance.

Date When Full Compliance Will Be Achieved:

STPNOC achieved full compliance on November 2, 2023, when all affected ECW expansion joints were restored to the design configuration using corrected work instructions.