DCL-01-095, Response to NRC Request for Additional Information Re License Amendment Request 01-03, Expansion of Steam Generator Tube W* Alternate Repair Criteria for Indications in Westinghouse Explosive Tube Expansion (Wextex) Region.

Response to NRC Request for Additional Information Re License Amendment Request 01-03, Expansion of Steam Generator Tube W* Alternate Repair Criteria for Indications in Westinghouse Explosive Tube Expansion (Wextex) Region.

ML020860452
Person / Time
Site:	Diablo Canyon
Issue date:	03/14/2002
From:	Rueger G Pacific Gas & Electric Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
DCL-01-095, DCL-02-027, LAR 01-03
Download: ML020860452 (5)

Text

Pacific Gas and Electric Company Gregory M. Rueger US Mail:

Senior Vice President- Mail Code B32 Generation and Pacific Gas and Electric Company Chief Nuclear Officer PO Box 770000 San Francisco, CA 94177-0001 March 14, 2002 Overnight Mail Mail Code B32 PG&E Letter DCL-02-027 77 BealeGasStreet, Pacific 32nd Floor and Electric Company San Francisco, CA 94105-1814 U.S. Nuclear Regulatory Commission 415.973.4684 Fax: 415.973.2313 ATTN: Document Control Desk Washington, DC 20555-0001 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 Response to NRC Request for Additional Information Regarding License Amendment Request 01-03, "Expansion of Steam Generator Tube W* Alternate Repair Criteria for Indications in the Westinghouse Explosive Tube Expansion (WEXTEX) Region"

Dear Commissioners and Staff:

On March 1, 2002, the NRC staff identified additional information required in order to complete its evaluation associated with License Amendment Request (LAR) 01-03. LAR 01-03 proposes Technical Specification changes to allow extension of steam generator tube W star (W*) alternate repair criteria through cycles 12 and 13.

LAR 01-03 was submitted to the NRC in PG&E Letter DCL-01-095, "License Amendment Request 01-03, Extension of Steam Generator Tube W* Alternate Repair Criteria for Indications in the Westinghouse Explosive Tube Expansion (WEXTEX) Region," dated September 13, 2001. The NRC staff questions were clarified during a telephone call between PG&E and the NRC staff on March 5, 2002. PG&E's response to the request for additional information is included in Enclosure 1.

This additional information does not affect the results of the safety evaluation and no significant hazards determination previously transmitted in PG&E Letter DCL-01-095.

If you have any questions regarding this response, please contact Patrick Nugent at (805) 545-4720.

A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway e Comanche Peak

• Diablo Canyon

• Palo Verde # South Texas Project

• Wolf Creek

Document Control Desk PG&E Letter DCL-02-027 March 14, 2002 Page 2 Sincerely, G M. Rueger Senior Vice President - Generation and Chief Nuclear Officer kjs/4328 Enclosure cc: Diablo Distribution cc/enc: Edgar Bailey, DHS Girija S. Shukla Ellis W. Merschoff David L. Proulx A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway , Comanche Peak s Diablo Canyon - Palo Verde

• South Texas Project - Wolf Creek

PG&E Letter DCL-02-027 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION

) Docket No. 50-275 In the Matter of ) Facility Operating License PACIFIC GAS AND ELECTRIC COMPANY) No. DPR-80

)

Diablo Canyon Power Plant ) Docket No. 50-323 Units 1 and 2 ) Facility Operating License

) No. DPR-82 AFFIDAVIT Gregory M. Rueger, of lawful age, first being duly sworn upon oath says that he is Senior Vice President - Generation and Chief Nuclear Officer of Pacific Gas and Electric Company; that he has executed this response to the request for additional information on License Amendment Request 01-03 on behalf of said company with full power and authority to do so; that he is familiar with the content thereof; and that the facts stated therein are true and correct to the best of his knowledge, information, and belief.

Gregqry M. R e-g-er Senior Vice President - Generation and Chief Nuclear Officer Subscribed and sworn to before me this 14 th day of March 2002.

County of San Francisco State of California AMY DAIKO DONG

~ Commission # 1206749

~~~ ~No'x Public - Ccalfri NoaýPublic Son rnllcisco Counly[

Enclosure 1 PG&E Letter DCL-02-027 PG&E Response to NRC Request for Additional Information Regarding License Amendment Request 01-03, Extension of Steam Generator Tube W*

Alternate Repair Criteria for Indications in the Westinghouse Explosive Tube Expansion (WEXTEX) Region Question 1 The six (6) in-situ test results which did not meet the in-situ screening criteria (Page 4, Table 1, of DCL-01-095) should not be used to validate the leak rate model.

PG&E Response to Question 1 The six in-situ tests that did not exceed the in-situ screening threshold values (identified in Table 1 of PG&E letter DCL-01-095, "License Amendment Request 01-03, Extension of Steam Generator Tube W* Alternate Repair Criteria for Indications in the Westinghouse Explosive Tube Expansion (WEXTEX) Region," dated September 13, 2001) will not be included as indications used to validate the W star (W*) leakage model. Therefore, an additional 14 indications are required to be tested in order to satisfy the commitment that 20 indications, summed over all plants with WEXTEX expansions, are tested. A revised Table 1, with these six in-situ tests removed, is provided below.

Table 1 Industry In-situ Test Results for Axial PWSCC in WEXTEX Region Plant Year SG Tube Deplug Crack Peak Crack Max Approx In-situ Test Leak Tube Distance Volt Length Depth Length > Test Pressure Rate Below (Volt) (Inch) (%) 80%, Required BWT, (Inch) due to (below TTS Exceeding for SQN Threshold and BVPS), Values (Inch)

DCPP 2 1999 1 R3C59 Yes 0.51 5.6 0.27 100% 0.23 Yes APNo 0 DCPP 2 1999 1 R7C62 Yes 0.59 4.2 0.35 80% None Yes APNO 0 DCPP 2 1999 2 R31C25 Yes 0.98 4.0 0.24 70% None Yes APNo 0 DCPP 2 2001 3 R7C52 Yes 0.56 3.4 0.43 94% 0.37 Yes APNo 0 DCPP 2 2001 4 R2C29 Yes 3.52 4.5 0.91 100% 0.84 Yes APNo 0 SQN 2 1997 4 R7C17 No 0.15 3.6 0.32 100% 0.02 Yes 3APNO 0 Question 2 DCL-01-095 states that "ifno leaking W* indicationsare obtained after 20 in-situ tests (summed over all plants with WEXTEX expansions), in-situ testing would be terminated for W* indicationsand PG&E will request a permanentARC." This commitment is not consistent with the originalcommitment in DCL-98-148.

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Enclosure 1 PG&E Letter DCL-02-027 PG&E Response to Question 2 PG&E will meet the original commitment in letter DCL-98-148, "Response to NRC Request for Additional Information, Dated August 6, 1998, Regarding Proposed W*

Steam Generator Tube Repair Criteria," dated October 22, 1998, which stated:

"W* indications that exceed the nondestructive examination (NDE) threshold values for in-situ testing will be leak tested to support the W* leakage model. In-situ testing would be continued until approximately 20 W* indications, summed over all plants with Westinghouse explosive tube expansion (WEXTEX) expansions, are tested. If a sufficient number of leaking W* indications are obtained to support the leakage model (i.e., the total leakage summed over all leaking indications is bounded by the calculated leakage for the leaking indications), in-situ testing would be terminated for W*

indications. If a sufficient number of leaking W* indications are not obtained after approximately 20 in-situ leak tests, Diablo Canyon Power Plant would initiate discussions with the NRC staff on whether to continue in-situ testing."

Question 3 In-situ testing screening criteriain Step I has no reference to W* indicationsthat have never been tested. How are those treated?

PG&E Response to Question 3 For the application of the in-situ testing screening criteria contained in DCL-01-095, for W* indications that have never been tested, the indications will be carried to Step 2.

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