ML20086D632

AO 73-18:on 730625,Barton Differential Pressure Switch Sensing RCIC Steam Line High Differential Pressure Actuated Below 150 Inches of Water.Switch Immediately Reset, Functionally Tested Ten Times & Verified within Tolerance

ML20086D632
Person / Time
Site:	Vermont Yankee
Issue date:	07/03/1973
From:	Riley B VERMONT YANKEE NUCLEAR POWER CORP.
To:	US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20086D635	List: ML20086D632 ML20086D649
References
AO-73-18, VYV-2754, NUDOCS 8312020427
Download: ML20086D632 (1)

Text

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r~ ,,9 v v s VERMONT YANKEE NUCLEAR POWER CORPORATION SEVENTY SEVEN OROVE STRECT RUT 1,AND, VEltMONT 03701 REPLY TO:

VYV-2754 p. O. box is7 VERNON, VERMONT 05354 July 3,1973

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REFERENCE:

Operating License DPR-28 <bN ~' ~

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Docket No. 50-271 ,{;  %"l,Q.-'

Abnormal Occurrence No. A0-73-18

Dear Sir:

As defined by Technical Specifications for the Vermont Yankee Nuclear Power Stat ion, .lection 6.7.B.1, we are reporting the following Abnormal Occurrence as A0-73-18.

At approximately 3015 on June 25, during conduct of RCIC Surveillance Testing, a Barton differential pressure switch sensing RCIC steam line high differential pressure (DPIS 13-83) actuated at -150" h 9 0. This constitutes a violation of the pressure setpoint specified in Table 3.2.2.3 of Technical Specifications, which requires actuation at a pressure 1180 115" 1120. The reactor was at approximately 78% at the time of this incident.

The switch was immediately reset, functionally tested 10 times, and verified to be within the tolerance specified during all ten functional tests.

This remedial action was completed in a time span that precluded the necessity of further immediate action.

The Plant Operations Review Committee concluded that although the pressure switch would not have operated within its specified tolerance, the logic would have actuated at the proper pressure because the companion switch (DPIS 13-84) was set properly and each one provides isolation via a one-of-two-once logic.

PORC also noted that the switch would have tripped at the proper setpoint with a positive differential pressure applied. Due to the fact that the switch had been in tolerance during the last 8 functional tests and since the switch is tested monthly, no additional surveillance beyond that regularly scheduled was deemed necessary for the subject switch.

gRADOCK12O20427 730703 Very truly yours, 8 05000271 PDR VERMONT YANKEE NUCLEAR POWER CORPORATION f) -

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