05000206/LER-1981-004, Forwards LER 81-004/01T-0.Detailed Event Analysis Encl

Forwards LER 81-004/01T-0.Detailed Event Analysis Encl

ML13333A738
Person / Time
Site:	San Onofre
Issue date:	05/04/1981
From:	Haynes J SOUTHERN CALIFORNIA EDISON CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML13333A739	List: 05000206/LER-1981-004, Forwards LER 81-004/01T-0.Detailed Event Analysis Encl 05000206/LER-1981-004-01, /01T-0:on 810416,consultants Determined That non- Metallic Internals of Actuators,Regulators & Solenoid Valves of Recirculation Flow Control Valves 1115 D,E & F Required Replacement.Caused by Aging.Internals Being Replaced
References
NUDOCS 8105120363
Download: ML13333A738 (2)

LER-1981-004, Forwards LER 81-004/01T-0.Detailed Event Analysis Encl

Event date:
Report date:
2061981004R00 - NRC Website

text

Southern California Edison Compan P. 0.

BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 J. G. HAYNES MANAGER OF NUCLEAR OPERATIONS May 4, 1981 U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region V 1990 North California Boulevard Suite 202, Walnut Creek Plaza Walnut Creek, California 94596 Attention:

Mr. R. H. Engelken, Director DOCKET NO. 50-206 SAN ONOFRE UNIT 1

Dear Sir:

By letter dated April 16, 1981 to the Director of Nuclear Reactor Regulation (copy to your office) we provided written, prompt notification of a reportable occurrence involving the recirculation flow control valves (FCV 1115 D, E and F).

These valves are utilized to modulate the flow of cooling water from the sump to the reactor core during long-term recirculation following a loss of coolant accident. This letter provides the two week followup report and the licensee event report (LER No.81-004) in accordance with Specification 6.9.2.a of the San Onofre Unit 1 Technical Specifications.

As a result of our efforts to obtain additional information to demonstrate qualification of safety-related electrical equipment to the DOR Guidelines, we have determined that the recirculation flow control valves contain nonmetallic material in the actuators, regulators and solenoid valves for the valves.

The diaphragm in the actuator is made of Buna-N material; the regulators contain gaskets, 0-rings and a diaphragm assembly made of Buna-N; and the solenoid valves contain nylon discs and Buna-N seats and gaskets.

Our evaluation indicates that this material has a limited life which may have already been exceeded and we cannot guarantee the valves would be capable of performing their safety function during recirculation.

Accordingly, the actuator diaphragm and solenoid internals are being replaced with like material and the regulator is being replaced with a similar regulator. Replacement with like material will ensure that the valves will be capable of operating for approximately two years. A maintenance schedule will be developed such that the above identified parts will be replaced prior to exceeding their qualified life.

Mr. R.

May 4, 1981 If you have any questions, please call me.

Very truly yours, J. G. Haynes Manager of Nuclear Operations ACLl oren s:wpl Enclosure cc: Director, Office of Management and Information Program Control (2)