ML13331A330
| ML13331A330 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 06/19/1989 |
| From: | Nandy F SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-89-001, IEB-89-1, NUDOCS 8906220069 | |
| Download: ML13331A330 (2) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 F. R. NANDY 19 1989 TELEPHONE MANAGER OF NUCLEAR LICENSING June 1 1 8 (818) 302-1896 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C.
20555 Gentlemen:
Subject:
Docket Nos. 50-206, 50-361 and 50-362 Response to NRC Bulletin No. 89-01:
Failure of Westinghouse Steam Generator Tube Mechanical Plugs San Onofre Nuclear Generating Station Units 1, 2 and 3
References:
- 1. NRC Bulletin No. 89-01: Failure of Westinghouse Steam Generator Tube Mechanical Plugs, dated May 15, 1989
- 2. Westinghouse Report WCAP-12244 (proprietary version),
"Steam Generator Tube Plug Integrity Summary Report," Revision 1, dated April 1989
- 3. Letter from Westinghouse to NRC dated May 1, 1989 (NS-NRC-89-3432);
Subject:
Steam Generator Tube Plug Integrity Update The purpose of this letter is to provide the information specified in the Reporting Requirements of Reference
- 1.
This information regards certain Westinghouse steam generator tube mechanical plugs which are susceptible to primary water stress corrosion cracking (PWSCC).
Reporting Requirement 1 requests information as specified in Actions Requested, Item 1, of Reference 1. A comprehensive review was conducted of steam generator tube plugging records for San Onofre Units 1, 2 and 3 to assess if any Westinghouse mechanical plugs from heat numbers 3279, 3513, 3962 and 4523 have been installed. This review determined that there are a total of 231 plugs from heat numbers 3513 and 4523 installed in San Onofre Unit 1 and no plugs from the four heat numbers listed above installed in Units 2 and 3. The results of this review were compared with the information provided in References 2 and 3 regarding the number of Westinghouse mechanical plugs installed in the hot and cold legs, broken down by steam generator number, heat number and date of installation and verified to be correct for the 231 plugs installed in Unit 1.
Reporting Requirement 2 requests a commitment to Actions Requested Items 2, 3 and 4 or proposed alternative actions with supporting justification.
SCE commits to comply with the Actions Requested Item 2 of Reference 1, but reserves the right to propose alternative actions with supporting justification prior to the next San Onofre Unit 1 refueling outage.
Document Control Des 0 0
June 19, 1989 Specifically, in response to Item 2(a),
the remaining life of all 231 plugs identified above has been estimated using the methodology from Reference 2, and it has been determined that all have enough remaining life to perform as designed through the next refueling outage (approximately 458 effective full power days of operation). In response to Item 2(b), remedial actions (i.e., repair and/or replacement) are not necessary prior to the next refueling outage due to the remaining life of the subject plugs.
In response to Item 2(c),
SCE will evaluate the various plug repair or replacement methods available from an ALARA standpoint to determine the lowest overall personnel radiation exposure approach, while still remaining cost-effective.
In response to Item 2(d),
installation of Westinghouse mechanical plugs from heats 3279,
- 3513, 3962 and 4523 has been discontinued. In response to Item 2(e), Westinghouse mechanical plugs removed from the steam generators, regardless of heat number, will be examined for PWSCC on a sample basis for each heat.
Actions Requested Item 3 for plugs in the partially depth-expanded tubes within the tubesheet in Unit 1 steam generators does not apply, since no outage is scheduled prior to October 1, 1989.
Actions Requested Item 4 does not apply since no "sentinel related" mechanical plugs were installed in Unit 1.
Please advise me if you require additional information regarding this matter.
Respectfully submitted, 6y.
/_
F. R. Nandy I
Manager of Nucle a' Licensing Subscribed and sworn to before me this
/1fA day of f OFFICIAL SEAL CAROL A.GOMEZ NOTARY PU8UC - CAUFORNIA LOS ANGELES COUNTY My Comm. Exres Foo. 2, 1993 Notary Public in and for the /?unty of Los Angeles, State of Califo~r a
cc: J. B. Martin, Regional Administrator, NRC Region V F. R. Huey, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3