ML13333A473

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Submits Addl Info Requested by NRC Re Auxiliary Feedwater Sys Flow Requirements.Provides Completion Schedule of Six to Eight Months for Requested Info
ML13333A473
Person / Time
Site: San Onofre Southern California Edison icon.png
Issue date: 01/16/1980
From: Baskin K
Southern California Edison Co
To: Harold Denton, Eisenhut D
Office of Nuclear Reactor Regulation
References
TAC-44652, TASK-10, TASK-RR NUDOCS 8001220472
Download: ML13333A473 (2)


Text

Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 K. P. BASKIN January 16, 1980 TELEPHONE

MANAGER, GENERATION ENGINEERING 213-572-1401 Director, Office of Nuclear Reactor Regulation Attention:

Mr. D. G. Eisenhut, Acting Director Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D. C.

20555 Gentlemen:

Subject; Docket No. 50-206 NRC Requirements for Auxiliary Feedwater System San Onofre Nuclear Generating Station Unit 1 By letter dated December 21, 1979, you requested additional information concerning the applicability of current analyses of a main steam line break or main feedwater line break assuming early initiation of auxiliary feedwater flow with a failure to limit flow to the affected steam generator. In addition, Enclosure 2 to your November 15, 1979 letter contained a generic request for additional information regarding Auxiliary Feedwater System flow requirements. Our letter dated January 2, 1980 indicated that based on initial discussions with Westinghouse it may require from six to eight months to provide the requested information.

The purpose of this letter is to advise you that further discussions with both Westinghouse and Bechtel, in attempts to improve the six to eight month schedule, has substantiated this schedule. The basis for the completion schedule is as follows:

1. Westinghouse will require until June 1, 1980, (approximately four months), to perform the main steamline break analysis to determine core response and to calculate mass and energy released to containment. The calculated mass and energy released to containment will then be provided to Bechtel to determine the containment response.

Bechtel will require until September 1, 1980, (approximately three months), to determine the containment response.

In each case, extensive computer modeling is required prior to performing the analysis to accurately reflect the San Onofre Unit 1 systems configuration.

2.

Subsequent to completion of the main steamline break analysis discussed in 1 above, the consequences of a main feedwater line break will be evaluated with respect to core response and mass.

and energy released to containment.

It is anticipated that this 1

S8001220 C

0

-2 evaluation may also require the joint efforts of Westinghouse and Bechtel; however, since the same individuals will be performing this evaluation as are performing the main steamline break analysis, the exact completion schedule for this evaluation is indeterminate at this time.

Efforts will be made to complete the evaluation coincident with the main steamline break analysis (i.e., by September 1, 1980).

3. Westinghouse will require until August 1, 1980, (approximately six months), to provide the information regarding Auxiliary Feedwater System flow requirements.

The preparation of this information is dependent, in part, on the information to be provided in 1 and 2 above.

Based on the completion schedules discussed above, it is expected that the information requested by Enclosure 2 of your November 15, 1979 letter and your December 21, 1979 letter can be submitted by October 1, 1980, which provides sufficient time for our internal review prior to submittal to the NRC. Currently, we are continuing to work with Westinghouse and Bechtel to improve the above schedules and will advise you of any ability to provide the requested information sooner than discussed above.

In accordance with your December 21, 1979 letter, we will not implement automatically initiated Auxiliary Feedwater System flow as required by Short-Term Recommendation 2.1.7.a of NUREG-0578, "Auto Initiation of the Auxiliary Feedwater System," as clarified by the NRC letter dated October 30, 1979, until you have reviewed and approved the requested information provided as discussed in 1 and 2, above.

If you have any questions, or desire additional information concerning our plans discussed above, please contact me.

Very truly yours,