ML13331B285
| ML13331B285 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 08/31/1990 |
| From: | Nandy F Southern California Edison Co |
| To: | NRC/IRM |
| References | |
| IEB-88-008, IEB-88-8, NUDOCS 9009050408 | |
| Download: ML13331B285 (2) | |
Text
Southern Calfornia Edison Company 23 PARKER STREET IRVINE. CALIFORNIA 92718 August 31, 1990 F. R. NANDY TELEPHONE MANAGER. NUCLEAR LICENSING (714) 587-5400 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C.
20555 Gentlemen:
Subject:
Docket Nos. 50-206, 50-361 and 50-362 NRC Bulletin No. 88-08: "Thermal Stresses in Piping Connected to Reactor Coolant Systems" San Onofre Nuclear Generating Station Units 1, 2, and 3
Reference:
January 8, 1990 letter from F. R. Nandy (SCE) to the NRC
Subject:
NRC Bulletin No. 88-08 This letter reports the completion of commitments made in Reference 1 to modify piping systems at San Onofre Units 2 and 3. This letter also discusses Southern California Edison's continuing review of thermal stresses at Units 1, 2, and 3.
We committed in the above reference to make changes to the pressurizer auxiliary spray piping at Units 2 and 3 during the Cycle 5 outages for each Unit. These changes consisted of relocating a check valve and replacing all the affected portions of piping that could have been exposed to cyclic thermal stresses that were not evaluated in the design analysis of the piping. With this change, the potential for cyclic thermal stresses in these lines is no longer a concern. The above reference reported the completion of these design changes at Unit 2. This letter reports the completion of these design changes at Unit 3.
Our reviews of thermal stresses in piping to date have not addressed Supplement 3 to NRC Bulletin 88-08. We are continuing to evaluate the applicability of this supplement in conjunction with applicable owners groups and other available information regarding thermal stratification and temperature oscillations on piping systems attached to the reactor coolant system at San Onofre Units 1, 2, and 3.
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Document Control Desk August 31, 1990 If you need additional information or have questions on this issue, please let me know.
Respectfully submitted, F. R. Nandy Manager, Nuclear Lic ing Subscribed and sworn to before me his day of NOTARY PUBLIC STATE OF CALIFORNIA County of Orange Notary Public in the State HOLLY nD.niEp of California cc:
J. B. Martin, Regional Administrator NRC Region V C. Caldwell, NRC Senior Resident Inspector, San Onofre Units 1, 2, and 3 J. E. Tatum, NRC Project Manager, San Onofre Unit 1