DCL-07-105, ASME Section XI Inservice Inspection Program Relief Request REP-1 U2, Revision 1; Response to Request for Additional Information
| ML073460045 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 11/29/2007 |
| From: | Becker J Pacific Gas & Electric Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| DCL-07-105, REP-1 U2, Rev 1 | |
| Download: ML073460045 (3) | |
Text
Pacific Gas and Electric Company' James R. Becker Diablo Canyon Power Plant Vice President P. 0. Box 56 Diablo Canyon Operations and Avila Beach, CA 93424 Station Director November 29, 2007 805.545.3462 Fax: 805.545.4234 PG&E Letter DCL-07-105 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Docket No. 50-323, OL-DPR-82 Diablo Canyon Unit 2 ASME Section XI Inservice Inspection Program Relief Request REP-1 U2, Revision 1; Response to Request for Additional Information
References:
- 1.
PG&E Letter DCL-07-038, "ASME Section XI Inservice Inspection Program Relief Request REP-1 U2," dated March 28, 2007
- 2.
PG&E Letter DCL-07-099, "ASME Section XI Inservice Inspection Program Relief Request REP-1 U2, Revision 1, and Response to Request for Additional Information," dated October 22, 2007
Dear Commissioners and Staff:
By letter dated March 28, 2007 (Reference 1), and supplemented by letter dated October 22, 2007 (Reference 2), Pacific Gas & Electric Company (PG&E) requested NRC approval of Inservice Inspection (ISI) Program Relief Request REP-1 U2. This request for relief contains alternative requirements for the ASME Section XI Repair/Replacement Program for scheduled preemptive full structural weld overlays (SWOLs) to mitigate the effects of primary water stress corrosion cracking of susceptible material at Diablo Canyon Power Plant (DCPP) Unit 2. This work is planned to be done during the DCPP Unit 2 Fourteenth Refueling Outage (2R14) currently scheduled to begin February 4, 2008.
In Reference 2, PG&E committed to implement the ISI requirements of ASME Section XI, Appendix Q, Subarticle Q-4300 for the life of the overlay, with the exception that flaws detected in the overlay that are due to stress corrosion cracking that exceed the standards of Table IWB-3514-2 are not allowed.
By emails dated November 6, 2007, and November 20, 2007, the NRC requested clarification regarding the ASME Code requirements to be used for the pressurizer weld overlay ISI. In response, the edition of the ASME Code to be used is the 2004 Edition, with 2005 Addenda. Also, the reference to Subarticle Q-4300 is intended to include the requirements of Q-4310.
A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Caltaway
- Comanche Peak
- Diablo Canyon
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- South Texas Project 9 Wolf Creek
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a Document Control Desk November 29, 2007 Page 2 PG&E Letter DCL-07-105 Accordingly, paragraph 3(c)(1) of ASME Section Xl Inservice Inspection Program Relief Request REP-1 U2, Revision 1, Attachment 1 to Enclosure 2 of Reference 2, is revised as follows:
The inservice inspection (ISI) requirements of ASME Code 2004 Edition, including 2005 Addenda,Section XI, Appendix Q, Subarticle Q-4300 (including Q-4310), shall apply for the third ten-year ISI interval for the weld overlay examination. The ISI requirements for the weld overlays for the fourth and later ISI intervals shall be those incorporated by reference in Title 10, Code of Federal Regulations, Part 50.55a (10 CFR 50.55a) in effect at that time.
This communication includes a revised commitment to be implemented following NRC approval of this relief request. The commitment is contained in Enclosure 1.
If you have any questions, please contact Mr. Stan Ketelsen at (805) 545-4720.
James R. Beb*er N
Vice President - Diablo Canyon Operations and Station Director tcg/4231 A0690550 Enclosures cc:
Diablo Distribution cc/enc:
Gary W. Butner, Acting Branch Chief, California Department of Public Health Elmo E. Collins, Regional Administrator, NRC Region IV Michael S. Peck, NRC Senior Resident Inspector Alan B. Wang, Project Manager, Office of Nuclear Reactor Regulation State of California, Pressure Vessel Unit A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
- Comanche Peak
- Diablo Canyon e Palo Verde ° South Texas Project
- Wolf Creek PG&E Letter DCL-07-105 Commitments
- 1)
The inservice inspection requirements of ASME Code 2004 Edition, including 2005 Addenda,Section XI, Appendix Q, Subarticle Q-4300 (including Q-4310), shall apply for the third 10-year inservice inspection interval for the weld overlay examination, with the exception that flaws detected in the overlay that are due to stress corrosion cracking that exceed the standards of Table IWB-3514-2 are not allowed. The inservice inspection requirements for the weld overlays for the fourth and later inservice inspection intervals shall be those incorporated by reference in Title 10, Code of Federal Regulations, Part 50.55a (10 CFR 50.55a) in effect at that time.