ML17018A132
| ML17018A132 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 01/18/2017 |
| From: | Welsch J Pacific Gas & Electric Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| DCL-17 -003, NDE-RCS-SE-1R20 | |
| Download: ML17018A132 (3) | |
Text
James M. Welsch Pacific Gas and Electric Company Vice President, Nuclear Generation Diablo Canyon Power Plant Mail Code 104/6 January 18, 2017 PG&E Letter DCL-17 -003 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Docket No. 50-275, OL-DPR-80 Diablo Canyon Power Plant (DCPP) Unit 1 P. 0. Box 56 Avila Beach, CA 93424 805.545.3242 Internal: 691.3242 Fax: 805.545.4884 10 CFR 50.55a Supplement 2: ASME Section XI lnservice Inspection Program Relief Request NDE-RCS-SE-1 R20 to Allow Use of Alternative Depth Sizing Criteria
Reference:
- 1. PG&E Letter DCL-16-115, "Supplement: ASME Section XI lnservice Inspection Program Relief Request NDE-RCS-SE-1 R20 to Allow Use of Alternative Depth Sizing Criteria," dated November 10, 2016 (ADAMS Accession No. ML16315A335)
Dear Commissioners and Staff:
In Reference 1, Pacific Gas and Electric Company (PG&E) submitted a supplement for a relief request to allow the use of alternative depth sizing criteria. In Section 5 of Reference 1, it was stated that PG&E was in the vendor selection process at the time of that submittal. Therefore, references to vendor depth sizing root mean square error (RMSE) values were generic. Subsequent to the submittal of Reference 1, PG&E completed the vendor selection process and selected WesDyne to perform ultrasonic volumetric examination of the reactor coolant system dissimilar metal welds and ~ssociated safe-end to piping welds. This submittal supplements Reference 1. RMSE values associated with the procedure to be used for depth sizing by WesDyne are presented in the Enclosure.
PG&E makes no new or revised regulatory commitments (as defined by NEI 99-04) in this letter. If you have any questions or require additional information, please contact Mr. Hossein Hamzehee at (805) 545-4720.
Sincerely, A member of the STARS Alliance Callaway
- Diablo Canyon
- Palo Verde
- Wolf Creek
Document Control Desk January 18, 2017 PG&E Letter DCL-17-003 Page 2 rntt/4231/50652488-17 Enclosure cc:
cc/encl:
Diablo Distribution Kriss M. Kennedy, NRC Region IV Administrator Christopher W. Newport, NRC Senior Resident Inspector Balwant K. Singal, NRC Senior Project Manager State of California, Pressure Vessel Unit A member of the STARS Alliance Callaway
- Diablo Canyon
- Palo Verde
- Wolf Creek
Enclosure PG&E Letter DCL-17-003 Supplement 2: ASME Section Xllnservice Inspection Program Relief Request NDE-RCS-SE-1 R20 to Allow Use of Alternative Depth Sizing Criteria 10 CFR 50.55a Relief Request NDE-RCS-SE-1 R20
Reference:
- 1. PG&E Letter DCL-16-115, "Supplement: ASME Section Xllnservice Inspection Program Relief Request NDE-RCS-SE-1 R20 to Allow Use of Alternative Depth Sizing Criteria," dated November 10, 2016 (ADAMS Accession No. ML16315A335)
In Reference 1, Pacific Gas and Electric Company (PG&E) submitted a supplement for a relief request to allow the use of alternative depth sizing criteria. In Section 5 of Reference 1, it was stated that PG&E was in the vendor selection process at the time of that submittal. Therefore, references to vendor depth sizing root mean square error (RMSE) values were generic. Subsequent to the submittal of Reference 1, PG&E completed the vendor selection process and selected WesDyne to perform ultrasonic volumetric examination of the reactor coolant system dissimilar metal welds and associated safe-end to piping welds. RMSE values associated with the procedure to be used for depth sizing by WesDyne are presented below.
- 1.
WesDyne RMSE Values Examination of Dissimilar Metal Welds:
The RMSE value that is applicable to examination of dissimilar metal welds is 0.189 inches. This value is determined by Performance Demonstration Initiative (PDI) qualification applicable to WesDyne's examination of dissimilar metal welds with the equipment and procedures that will be used at Diablo Canyon Power Plant (DCPP) Unit 1.
Examination of Stainless Steel (Non-Dissimilar) Welds from the Inside Diameter (ID) Surface:
The RMSE value that is applicable to examination of stainless steel (non-dissimilar) welds from the ID surface is 0.245 inches. This value is determined by PDI qualification applicable to WesDyne's examination of stainless steel welds with the equipment and procedures that will be used at DCPP Unit 1.
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