ML20040C697

LER 81-036/03L-0:on 811217,containment Isolation Valve CU-15 Failed to Seat Satisfactorily Per Tech Spec 4.7.D.1 During Quarterly Surveillance Testing.Caused by Failure of Closing Torque Switch.Torque Switch Will Be Replaced Next Shutdown

ML20040C697
Person / Time
Site:	Vermont Yankee
Issue date:	01/16/1982
From:	Murphy W VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20040C689	List: ML20040C688 ML20040C697
References
LER-81-036-03L, LER-81-36-3L, NUDOCS 8201290161
Download: ML20040C697 (2)

Text

NRC PM6 U. S. NUCLEAQ REGULATORY COMMISSION (7 77)

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68 69 EVENT D ATE 74 75 REPORT DATE 80 EVENT OESCRIPTION ANO PROBABLE CONSEO'.'ENCES h I o l71 l At full power, containment isalation valve CU-15 failed to seat satisfactorily per l I o i 31 l Tech Spec 4.7.D.1 during Quarterly Surveillance Testing. RWCU was removed from I l o 141 I service and CU-18 shut to provide containment isolation per Tech Spec 3.7.D.2. I l o I s j l There were no consequences to the public health and saf ety. There were no previous l IO16I Ioccurreiices of this t-ne renorted within the last 9 viars_ l l o 17 l l l 10181l I DE CODE SUSC E COMPONENT CODE SUSCODE S E 10191 7 d l Cl Gl@ W@ l Bl@ l I3Vl Al Ll Vl 0l Pl@ l Al@ W @

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NMM CF PAEPARER arren P. Mtirphy PHONE.

(802) 257-7711 2,

VTVYS1 05000271 j LER 81-36/3L CAUSE DESCRIPTION AND CORRECTIVE ACTIONS:

The cause of the problem was failure of the closing torque switch. The torque switch in series with the seal in contact was disconnected from the circuit.

A time delay drop out relay was installed such that the close cc,il remains energized after the limit switch opens, allowing the valve to fully seat.

The torque switch located inside the drywell will be replaced during the next cold shut down. RWCU was placed back in service upon declaring CU-15 operable.

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