ML19308B027

Unusual Event 269/73-14:on 731208,during Reactor Bldg remotely-operated Isolation Valve & Engineered Safeguards Valve Functional Test,Engineered Safeguards Valve RC-7 Failed to Open on Signal from Engineered Safeguards Panel

ML19308B027
Person / Time
Site:	Oconee
Issue date:	01/07/1974
From:	DUKE POWER CO.
To:
Shared Package
ML19308B025	List: ML19308B024 ML19308B027
References
RO-269-73-14, NUDOCS 7912120785
Download: ML19308B027 (1)

Text

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s DUKE POWER COMPANY / . ,'- . -g)f OCONEE NUCLEAR STATION - UNIT 1 j *g 30 M %y UNUSUAL EVENT REPORT UE-269/73-14 - -

ENGINEERED SAFEGUARDS VALVE RC-7 O -

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Description of the Incident on December 8, 1973, the Reactor Building Remotely Operated Isolation Valve and ,

l Engineered Safeguards Valve Functional Test was performed. During the test, the engineered safeguards valve RC-7, a pneumatic operated reactor building isolation valve in the pressurizer sample line, failed to open on signal from the engineered safeguards panel. The valve closed as would be required for engineered safeguards actuation; however, the valve jammed in its seat and could not be reopened from the ES Panel. Regulatory Operations, Region II, was informed of this incident on December 8, 1973.

Corrective Action When the valve RC-7 could not be opened remotely, it was manually unseated and opened. The valve operator was then adjusted to prevent seating the valve with l excessive force. After these adjustments, the valve was cycled several times and operated properly. The valve was then tested daily for three days and operated properly each day.

Safety Analysis Engineered Safeguards Valve RC-7 is one of two valves in the pressurizer sample line which provide reactor building isolation in the event of engineered safe-guards actuation. The redundant valve, RC-5, was tested at the time of the incident aid operated properly. Furthermore, RC-7 functioned as would be required on engineered safeguards actuation. This incident did not affect the safe oPerationoftheplantorthehealthandsafetyofthepublic.,gg1g1gO((W ,