ML13322B145
| ML13322B145 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 05/02/1990 |
| From: | Nandy F SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9005040266 | |
| Download: ML13322B145 (2) | |
Text
Southern California Edison Company 23 PARKER STREET IRVINE, CALIFORNIA 92718 F. R. NANDY TELEPHONE MANAGER OF NUCLEAR LICENSING May 2, 1990 (714 587-5400 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555 Gentlemen:
Subject:
Docket No. 50-206 ATWS Rule, 10 CFR 50.62 San Onofre Nuclear Generating Station, Unit 1 The purpose of this letter is to provide a revised schedule for submittal of information requested in your letter dated February 13, 1990, regarding the ATWS Mitigation System for SONGS 1. You requested the results of the Westinghouse site-specific analysis to establish the auxiliary feedwater (AFW) flow requirements, identification of generic design assumptions relative to the ATWS rule that do not apply to SONGS 1, and our resolution of any such discrepancies. You requested this information within 30 days of the receipt of the letter, or as soon thereafter as possible.
We provided a letter on March 26, 1990, to inform you the Westinghouse site specific analyses would be provided by April 30, 1990. However, Westinghouse required additional time to complete the analyses for the following reasons:
0 An additional ATWS transient analysis was necessary for the Loss of Offsite Power case.
o We determined the ASME Code Section III Service Level C stress criteria was not applicable to SONGS 1; therefore, Westinghouse performed stress analyses for the entire RCS to establish the plant-specific RCS pressure acceptance criteria for SONGS 1.
We are currently reviewing the preliminary report on these analyses. We plan to submit the final results for NRC review at the earliest possible date, which we expect to be May 31, 1990. We will also provide the description and resolution of generic design assumptions relative to the ATWS rule not applicable to SONGS 1 at that time.
As a result of our effort to identify generic design assumptions not applicable to SONGS 1, we have determined additional Westinghouse site specific analyses are necessary for certain DNBR limiting ATWS events. These analyses will determine if the SONGS 1 is bounded by the Westinghouse generic analyses with respect to DNBR during an ATWS. The generic Westinghouse PDC -d
Document Control Desk May 2, 1990 analyses show DNBR is not a concern. We plan to submit the DNBR limiting ATWS analyses at the earliest possible date, which we expect to be August 15, 1990.
If you have any questions or comments, please let me know.
Sincerely, cc:
J. B. Martin, Regional Administrator, NRC Region V C. Caldwell, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3