ML070990181
| ML070990181 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 04/30/2007 |
| From: | Wang A NRC/NRR/ADRO/DORL/LPLIV |
| To: | Keenan J Pacific Gas & Electric Co |
| Wang A, NRR/DORL/LPLIV, 415-1445 | |
| References | |
| BL-04-001, TAC MC3477 | |
| Download: ML070990181 (5) | |
Text
April 30, 2007 Mr. John S. Keenan Senior Vice President and Chief Nuclear Officer Pacific Gas and Electric Company Diablo Canyon Power Plant P.O. Box 770000 San Francisco, CA 94177-0001
SUBJECT:
BULLETIN 2004-01, INSPECTION OF ALLOY 82/182/600 MATERIALS USED IN THE FABRICATION OF PRESSURIZER PENETRATIONS AND STEAM SPACE PIPING CONNECTIONS AT PRESSURIZED-WATER REACTORS, RESPONSE FOR DIABLO CANYON POWER PLANT, UNIT NO. 2 (TAC NO. MC3477)
Dear Mr. Keenan:
On May 28, 2004, the U.S. Nuclear Regulatory Commission (NRC) issued Bulletin 2004-01, Inspection of Alloy 82/182/600 Materials Used in the Fabrication of Pressurizer Penetrations and Steam Space Piping Connections at Pressurized-Water Reactors, to the industry. This bulletin informed addressees that current methods of inspecting the pressurizer penetrations and steam space piping connections fabricated from Alloy 82/182/600 materials may need to be supplemented with additional measures (e.g., bare-metal visual inspections) to detect pressurizer penetration and steam space piping connection flaws or leakage. The bulletin requested that addressees provide the NRC with information related to the materials of construction, the inspections that have been performed, and the inspections that will be performed to verify the integrity of the pressurizer penetrations and steam space piping connections.
By letter dated July 27, 2004 (and by a supplemental "DCL-05-008, Day Response to NRC BL-03-002, Leakage from Reactor Pressure Vessel Lower Head Penetrations and Reactor Coolant Pressure Boundary Integrity, [[NRC bulletin" contains a listed "[" character as part of the property label and has therefore been classified as invalid., Inspection of Alloy 82/182/600 Materials Used|letter dated February 8, 2005]]), Pacific Gas and Electric Companby (PG&E) provided its responses to items 1a, 1b, 1c, and 1d of Bulletin 2004-01 for Diablo Canyon Power Plant (DCPP), Unit No. 2. PG&Es responses described its materials of fabrication and past, current, and future pressurizer penetrations and steam space piping inspection programs at DCPP.
PG&Es response to item 1a reported that some of the materials used in the fabrication of the pressurizer penetrations and steam space piping connections were Alloy 82/182/600 materials.
This reply required you to provide further responses to the remaining items in the bulletin.
In response to item 1b, PG&E described prior inspections and inspection results of pressurizer penetrations and steam space piping connections, which had been performed at DCPP.
PG&Es response included the basis for concluding that DCPP satisfies the applicable regulatory requirements related to the integrity of pressurizer penetrations and steam space piping connections.
J. Keenan In response to item 1c in the bulletin, PG&E provided a description of the Alloy 82/182/600 pressurizer penetration and steam space piping connection inspection program that will be implemented at your plant during the next and subsequent refueling outages. The description included the items to be inspected; the percent coverage that would be performed at each location; the inspection methods to be used; the qualification standards for the inspection methods and personnel; the process used to resolve any inspection indications; the inspection documentation to be generated; and the basis for concluding that your plant will satisfy the applicable regulatory requirements related to the structural and leakage integrity of pressurizer penetrations and steam space piping connections. If leaking pressurizer penetrations or steam space piping connections are found, PG&E indicated that follow-up nondestructive examination (NDE) will be performed to characterize flaws in the leaking penetrations. PG&E provided its plans for expansion of the scope of NDE to be performed if circumferential flaws are found in any portion of the leaking pressurizer penetrations or steam space piping connections.
In response to item 1d in the bulletin, PG&E explained why the inspection program identified in the response to item 1c in the bulletin is adequate for the purpose of maintaining the integrity of the DCPP reactor coolant pressure boundary and for meeting all applicable regulatory requirements, which pertain to your facility.
By "DCL-05-008, Day Response to NRC BL-03-002, Leakage from Reactor Pressure Vessel Lower Head Penetrations and Reactor Coolant Pressure Boundary Integrity, [[NRC bulletin" contains a listed "[" character as part of the property label and has therefore been classified as invalid., Inspection of Alloy 82/182/600 Materials Used|letter dated February 8, 2005]], PG&E provided a response to item 2a in Bulletin 2004-01.
This letter provided a statement to the NRC indicating that the inspections described in your response to item 1c of the bulletin were completed during a recent DCPP outage and a description of the as-found condition of the locations inspected was provided. PG&E also described any findings of relevant indications of through-wall leakage and follow-up NDE performed to characterize flaws in leaking penetrations or steam space piping connections.
A summary of all relevant indications found by NDE, a summary of the disposition of any findings of boric acid, and a description of any corrective actions taken and/or repairs made as a result of the indications found was also provided in this letter.
The NRC staff has completed its activities associated with the review of PG&E's responses to Bulletin 2004-01 and finds PG&E's response to be acceptable. It should be noted that industry commitments or NRC staff regulatory actions may result in the need for you to modify your plans for the inspection and repair of items discussed in Bulletin 2004-01. For example, specific actions addressed in topical report MRP-139, "Materials Reliability Program: Primary System Piping Butt Weld Inspection and Evaluation Guideline," and/or plant-specific Confirmatory Action Letters regarding dissimilar metal butt welds encompassed by Bulletin 2004-01 may exceed the scope of actions addressed in your response to Bulletin 2004-01. It is the NRC staffs expectation that you will revise your plan for the inspection and repair of items discussed in Bulletin 2004-01 consistent with other industry commitments or NRC staff regulatory actions. This closes the staffs efforts with regard to the review of the Bulletin 2004-01 response for DCPP, Unit No. 2. Please contact me at (301) 415-1445, if you have any questions on this issue.
Sincerely,
/RA/
Alan Wang, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-323 cc: See next page
ML070990181 OFFICE NRR/LPL4/PM NRR/LPL4/LA DCI/CVIB/BC NRR/LPL4/BC NAME AWang LFeizollahi MMitchell THiltz DATE 4/30/07 4/30//07 4/24/07 4/30/07
January 2007 Diablo Canyon Power Plant, Units 1 and 2 cc:
NRC Resident Inspector Diablo Canyon Power Plant c/o U.S. Nuclear Regulatory Commission P.O. Box 369 Avila Beach, CA 93424 Sierra Club San Lucia Chapter ATTN: Andrew Christie P.O. Box 15755 San Luis Obispo, CA 93406 Ms. Nancy Culver San Luis Obispo Mothers for Peace P.O. Box 164 Pismo Beach, CA 93448 Chairman San Luis Obispo County Board of Supervisors 1055 Monterey Street, Suite D430 San Luis Obispo, CA 93408 Mr. Truman Burns Mr. Robert Kinosian California Public Utilities Commission 505 Van Ness, Room 4102 San Francisco, CA 94102 Diablo Canyon Independent Safety Committee ATTN: Robert R. Wellington, Esq.
Legal Counsel 857 Cass Street, Suite D Monterey, CA 93940 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission Harris Tower & Pavillion 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 Antonio Fernández, Esq.
Pacific Gas & Electric Company P.O. Box 7442 San Francisco, CA 94120 City Editor The Tribune 3825 South Higuera Street P.O. Box 112 San Luis Obispo, CA 93406-0112 Director, Radiologic Health Branch State Department of Health Services P.O. Box 997414, MS 7610 Sacramento, CA 95899-7414 Mr. James D. Boyd, Commissioner California Energy Commission 1516 Ninth Street (MS 31)
Sacramento, CA 95814 Mr. James R. Becker, Vice President Diablo Canyon Operations and Station Director Diablo Canyon Power Plant P.O. Box 56 Avila Beach, CA 93424 Jennifer Tang Field Representative United States Senator Barbara Boxer 1700 Montgomery Street, Suite 240 San Francisco, CA 94111