ML20148C466

Forwards SER Supporting Acceptance of Postponement of Certain Permanent ECCS Single Failure Fixes at Facility. Mod Includes Installation of Redundant Undervoltage Relays, Installation of Redundant Valve & Control Power Sys

ML20148C466
Person / Time
Site:	San Onofre
Issue date:	10/16/1978
From:	Ziemann D Office of Nuclear Reactor Regulation
To:	James Drake SOUTHERN CALIFORNIA EDISON CO.
Shared Package
ML20148C471	List: ML20148C466 ML20148C490
References
TASK-06-07.C2, TASK-6-7.C2, TASK-RR NUDOCS 7811020053
Download: ML20148C466 (3)

Text

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_ . _ . _ - _ DE POL UNITED STATES

, p* 4*g NUCLEAR REGULATORY COMMISSION g , ,, j WASHINGTON, D. C. 20555 j

k*****j[ October 16, 1978 Docket No. 50-206 Southern California Edison Company ATTN: Mr. James H. Drake -

Vice Presidont i

2244 Walnut Grove Avenue Post Office Box 800 l Rosemead, California 91770 Gentlemen:

This is in response to your letter dated August 10,1978, as supplemented by letter dated September 15, 1978, which proposed to postpone implementation of four ECCS single failure modifications to permit evaluation of the potential impact of implementation on other plant modifications which may be considered as part of the integrated assessment of the facility in the Systematic Evaluation Program (SEP).

The four modifications in question resulted from your ECCS single failure analys' Our evaluation of the modifications is described in our Safety b iation supporting the issuance of Amendment No. 25 on April 1, 197'. This evaluation was performed before the SEP was initiated. These modifications involve the following:

1. Installation of redundant undervoltage relays on each of the

,- 4160V busses 1C and 2C during the refueling outage for Cycle 7 operation.

2. Installation of a redundant valve in series with valve MOV/LCV 1100C during the refueling outage for Cycle 7 operation.

3. Modifications to provide independent and redundar not leg recirculation flow control capability during the ueling outage for Cycle 7 operation.

4. Installation of redundant control power and instrument air for flow control valves FCV-1115D, E, and F during the outage scheduled for Winter 1979-1980 for refueling for Cycle 8 operation.

Based on our review of your proposal we have concluded that post-ponement of items 2, 3, and 4 as described above is acceptable.

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6I I Southern California ~ Edison Company- i October 16, 1978  ;

We have concluded'that postponement of installation of the undervoltage t i relays item 1,. is not acceptable. In discussions with representatives of your. staff, wa understand that the modification will be made during  ;

the refueling _ outage for. Cycle 7 operation. '

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.Our Safety Evaluation supporting our conclusions is enclosed.

j Sincerely, i

NW .Y Dennis L. Zieman Chief Operating Reactors Branch #2 Division of Operating Reactors

Enclosure:

Safety Evaluation I

cc: See next page O

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Southern California Edison Company October 16, 1978 cc Rollin E. Woodbury, Vice President and General Counsel Director, Technical Assessment Division Southern California Edison Company Post Office Box 800 Office of Radiation Programs i

Rosemead, California 91770 (AW-459)

US EPA David R. Pigott Crystal Mall #2 Samuel B. Casey Arlington, Virginia 20460 Chickering & Gregory Three Embarcadero Center U. S. Environmental Protection Twenty-Third Floor Agency Region IX Office San Francisco, California 94111 ATTN: EIS COORDINATOR David W. Gilman 215 Freemont Street Robert G. Lacey San Francisco, California 94111 San Diego Gas & Electric Company Post Office Box 1831 San Diego, California 92112 Mission Viejo Branch Library 24851 Chrisanta Drive Mission Viejo, California 92676 Mayor City of San Clemente San Clemente, California 92676 Chairman Board of Supervisors County of San Diego San Diego, California 92101 California Department of Health ATTN: Chief. Environmental Radiation Control Unit Radiologic Health Section - '

714 P Street, Room 498 Sacramento, California 95814 l

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