ML19308A842

Unusual Event:On 730404,during Safeguards Test,Reactor Bldg Spray Valves BS-1 & BS-2 Failed to Open on Signal.Caused by Tight Seating.Sign Do Not Jam Valve Closed by Hand Posted. Operating Procedures Modified

ML19308A842
Person / Time
Site:	Oconee
Issue date:	04/04/1973
From:	DUKE POWER CO.
To:
Shared Package
ML19308A831	List: ML19308A830 ML19308A833 ML19308A842
References
NUDOCS 7912120632
Download: ML19308A842 (1)

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l FAILURE OF REACTOR BUILDING SPRAY VALVES TO OPEN DURING ES SYSTEM TESTING On April 4, 1973 and during routine monthly testing of the Engineered Safe-guards (ES) system, reactor building spray valves BS-1 and BS-2 failed to function when the ES system furnished the opening signal to the valve motor operators. These valves are eight inch ALOYC0 45 , 300 lb. globe valves with limitorque operators. The station superintendent was immediately notified, and he verbally reported the incident to Region II Regulatory Operations office in Atlanta, Georgia. The valve motors, limit switches, and torque switches were inspected but no indication of abnormalities was found. The valves were opened manually and it was found that the seating was extremely tight. After the valves were opened lually, they were successfu]ly operated using the valve motor operatses.

1 During recent hot functional testing, the valves BS-1 and BS-2 wera apparently manually closed to prevent some minor leakage through the seats. Consequently, the torque supplied by the valve motor operators was insufficient to reopen these valves.

After verification that valves BS-1 and BS-2 were operating properly, all other ES valves were checked to ensure they had not been jammed closed by manual operation. To prevent recurrence of a similar problem, the Station Review Committee has recommended that a sign be affixed to the manual hand-wheel of each ES valve stating, "Do not jam valve closed by hand." This recommendatica has already been accomplished. Also, operating procedures will require testing of any engineered safeguards valve electrically after

, it has been manually operated.

]91g120 b S

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