ML19340B214

Response to NRC Request for Additional Information Regarding 2019 Steam Generator Tube Inspections

ML19340B214
Person / Time
Site:	Palo Verde
Issue date:	12/06/2019
From:	Dilorenzo M Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-08019-MDD/CJS
Download: ML19340B214 (3)

Text

Technical Specification 5.6.8 Qaps Palo Verde Nuclear Generating Station 102-08019-MDD/CJS 5801 S. Wintersburg Road Tonopah, AZ 85354 December 6, 2019 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Palo Verde Nuclear Generating Station (PVNGS) Unit 1 Docket No. STN 50-528 License No. NPF-41 Response to NRC Request for Additional Information Regarding 2019 Steam Generator Tube Inspections By letter dated October 18, 2019 [Agencywide Documents Access and Management Systems (ADAMS) Accession No. ML19291F576], Arizona Public Service Company (APS) submitted information summarizing the results of the 2019 steam generator tube inspections at Palo Verde Nuclear Generating Station (PVNGS) Unit 1.

The NRC staff reviewed the information provided by APS and determined that additional information was needed to complete its review of the steam generator tube inspections. On November 13, 2019, the NRC staff provided a request for additional information (RAI) to APS, which requested that a response be submitted within 30 days. The APS response to the RAI is provided in the enclosure to this letter.

No commitments are being made to the NRC by this letter. Should you need further information regarding this response, please contact me at (623) 393-3495.

Sincerely, Michael D. DiLorenzo Nuclear Regulatory Affairs Department Leader MDD/aS/mg

Enclosure:

Response to Request for Additional Information for Steam Generator Tube Inspections in Unit 1 cc:

S. A. Morris NRC Region IV Regional Administrator S. P. Lingam NRC NRR Project Manager for PVNGS C. A. Peabody NRC Senior Resident Inspector for PVNGS A member of the STARS Alliance LLC Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek

Enclosure Response to Request for Additional Information for Steam Generator Tube Inspections in Unit 1

Enclosure Response to Request for Additional Information for Steam Generator Tube Inspections in Unit 1 Introduction By letter number 102-07999, dated October 18, 2019 [Agencywide Documents Access and Management Systems (ADAMS) Accession No. ML19291F576], Arizona Public Service Company (APS) submitted information summarizing the results of the 2019 steam generator (SG) tube inspections at the Palo Verde Nuclear Generating Station (PVNGS) Unit 1.

The NRC staff reviewed the information provided by APS and determined that additional information was needed to complete its review of the SG tube inspections. On November 13, 2019, the NRC staff provided a Request for Additional Information (RAI) to APS, which requested that a response be submitted within 30 days. The APS response to the RAI is provided as follows.

NRC Request 1 There appears to be a typographical error in Table 2, "Indication Summary," of the spring 2019 SG tube inspection report. In Table 2, "Indication Summary," of the 2016 SG tube inspection report dated October 26, 2016 (ADAMS Accession Number ML16308A232), a total of 130 tubes were reported to have been plugged in SGI2. The spring 2019 SG tube inspection report stated that 53 additional tubes in SG12 were plugged, however, the report only states a total of 173 tubes have been plugged in SG12. Please confirm that the total number of tubes plugged in SGI2 is 183.

APS Response APS confirms that there is a typographical error in Table 2, "Indication Summary," of the spring 2019 SG tube inspection report. The total number of tubes plugged in PVNGS Unit 1 SG number 12 is 183 tubes. This information is correctly documented on page 37 of 41 of the Unit 1 Steam Generator Inspection Report, transmitted by APS letter dated October 18, 2019. Specifically, page 37 of 41 documents that 130 tubes had been previously plugged in SG 12, and that 53 were to be plugged during the outage. As documented in Section 1, in Table 2, and the NIS-1 Form of the report, 53 tubes were plugged in SG 12 in the Unit 1 refueling outage number 21. This results in a total of 183 tubes that have been plugged in SG 12 of PVNGS Unit 1.

NRC Request 2 Appendix B, "Steam Generator 11 Summary Data Sheets," of the spring 2019 SG tube inspection report includes eddy current analysis code "RLW" for SG tube 41R88C. However, this code is not defined in the spring 2019 SG tube inspection report or the Electric Power Research Institute's Pressurized Water Reactor Steam Generator Examination Guidelines.

Please clearly define RLW.

APS Response The eddy current analysis code "RLW" is defined as: Retest Large Wear Standard, utilized when bobbin or rotating coil (RC) wear is greater than 50 percent. This definition is contained in the applicable PVNGS procedure 73TI-9RC01, Steam Generator Eddy Current Examinations, Appendix G. With regard to tube 41R88C (row 41, column 88), this tube is plugged, as are each of the other tubes with the characterization of "RLW" in both SGs.