ML19317F438

Unusual Event 270/75-22:on 751226,LPIS Valves LP-17 & LP-18 Found Manually Inoperable.Caused by Maladjusted Torque Switch Setting.Setting Readjusted & Valve Brake Release Mechanism Repaired

ML19317F438
Person / Time
Site:	Oconee
Issue date:	02/09/1976
From:	DUKE POWER CO.
To:
Shared Package
ML19317F427	List: ML19317F426 ML19317F438
References
RO-270-75-22, NUDOCS 8001140676
Download: ML19317F438 (1)

Text

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c (j DUKE POWER COMPANY OCONEE UNIT 2

'_ Report g : UE-270/75-22 Report Date: February 9, 1976 Event Date: December 26, 1975 Facility: Oconee Unit 2, Seneca, South Carolina Identification'of Event:

Low Pressure Injection System valves manually inoperable Conditions Prior to Event: Unit at 100% full power Description of Event:

On December 26, 1975, Low Pressure valves). Injection System valves LP-17 and LP-18 (LP1 he This annual surveillance test was performed at this time bec problem had existed on Oconce Unit The valves Engineered were mode.

Safeguards cycled electrically to verify their operability in the1 (Se Designation of Apparent Cause of Event:

for valve LP-18 had been set too high which prevented ma the valve..

r Valve LP-17 brake release buttons were discovered jammed which prevented the opprator from engaging the manual handwheel.

Analysis of Event:

Periodic testing as required by Oconee Technical Specification 4.5.1 . ..

22c b is performed on these valves to assure that they can be manually operated to provide be possible.long-term In this emergency event, core cooling should electrical operation not an Engineered Safeguards actuation signal been received.both valves would The manual operability of the valves was restored within approximately seven hours of discovery.

not affectedItby is this concluded that the health and safety of the public was incident. ,,

Corrective Action:

1 and the brake release mechanism on valve LP-17 Both valves has been r have.been tested electrically and manually.

_ performed satisfactorily on the similar LPI valves on Oconee Unit 3. Surveillanc Additionally, a change has been made to the maintenance procedure to require verification of manual the torque switch operability of LPI system valves after adjustment of setting. 4 8001140 b 7b

_