ML13324A826

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Provides Written Notification of Changes to Integrated Living Schedule Section V.B & Justification for Deferral of Implementation to Cycle 10.Waste Gas Decay Tank Instrumentation Being Upgraded
ML13324A826
Person / Time
Site: San Onofre Southern California Edison icon.png
Issue date: 03/26/1986
From: Medford M
Southern California Edison Co
To: Lear G
Office of Nuclear Reactor Regulation
References
TAC-54376 NUDOCS 8603310229
Download: ML13324A826 (2)


Text

Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 M.O.MEDFORD TELEPHONE MANAGER. NUCLEAR LICENSING (818) 302-1749 March 26, 1986 Director, Office of Nuclear Reactor Regulation Attention:

G. E. Lear, Director PWR Project Directorate No. 1 U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Gentlemen:

Subject:

Docket No. 50-206 Integrated Living Schedule Cycle IX Projects San Onofre Nuclear Generating Station Unit 1

References:

A. Letter, M. 0. Medford, SCE, to 3. A. Zwolinski, NRC, dated August 29, 1985 B. Letter, Kenneth P. Baskin, SCE, to H. R. Denton, NRC, dated May 23, 1984 The Reference A letter provided a revision of the Integrated Living Schedule (ILS) and the ILS Program Plan used to schedule capital backfits at San Onofre Unit 1. The Plan is designed to implement the proposed license condition of Reference B as modified in Reference A.Section V.B of the Plan provides guidance for changing the schedules of the ILS. In accordance with that section of the Plan, and due to the large number of modifications being accomplished during the current outage, it is necessary to defer implementation of certain projects.

This letter provides written notification of these changes and justification for deferral to Cycle 10 for implementation.

All projects being deferred from Cycle IX to Cycle X implementation are included on Schedule B of the ILS. Schedule B includes, among other things, regulatory items which have specific backfits identified and which SCE has agreed to implement. The projects being deferred are as follows:

o Regulated Instrument Buses o

CVCS Valves MOV-LCV-1100B, C, D o

Waste Gas Decay Tank Monitoring Instrumentation The Regulated Instrument Buses were scheduled to be modified by adding indicating lights for power trouble. The failure of one of these buses has previously caused erratic feedwater flow. This modification can be deferred to a later outage as vital buses to which the regulated buses are connected have indication in the control room. In addition, if a regulated bus fails, it would cause symptoms in the control room that would alert the operators to a potential problem.

8603310229 860326 PDR ADOCK 05000206 40

.P PDR n.

Mr. G.

March 26, 1986 The CVCS valves MOV-LCV, 1100B, C and D were identified as valves that change their state upon receipt of a Safety Injection signal and then return to their original position upon reset. The controls for these valves are to be modified to assure that the SI state is maintained even after the signal is reset. In the interim, administrative controls assure that the valves are kept in the SI state after SI reset.

The Waste Gas Decay Tank Monitoring Instrumentation is being upgraded and added due to previous difficulties in identifying leakage of radioactive gases from these tanks. The new instruments will be designed to readily identify the contents and conditions of the tanks.

The tanks are currently monitored regularly to fulfill this function.

If there are any questions, please let me know.

Very truly yours, cc:

J. B. Martin, NRC Region V, Regional Administrator F. R. Huey, USNRC Resident Inspector, Units 1, 2 and 3