ML20086D992

AO 73-24:on 730816,instrument Lines Monitoring Suppression Chamber Pressure Found Incorrectly Tubed to Differential Pressure Sensor Which Activates Breaker Operation,Causing Actuation W/Positive Pressure

ML20086D992
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	08/17/1973
From:	George Thomas VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20086D983	List: ML20086D979 ML20086D992
References
AO-73-24, VYV-2961, NUDOCS 8312050720
Download: ML20086D992 (2)

Text

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t VERMONT YANKEP. N UCLEAR POWER CORPORATION SEVENTY SEVEN OROVE STRCCT RUTLAND, VERMONT 03701

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REPLY TO:

VYV-2961 P. O. sox 157 VERNON. VERMONT 053s4 August 17, 1973

. -: ,,W y United States Atomic Energy Commissic.n ' ,

Directorate of Regulatory Operations, Region I

631 Park Avenue / 'I I 'Q,. 4 3.i,4 p'l O)

King of Prussia, Pennsylvania 19406 j' r ?,'.

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REFERENCE:

Operating License DPR-28 N

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$9&" .5/ 1 Docket No. 50-271 .

t" c' Abnormal Occurrence No. A0-73-24 \.3 [

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..V 4Qf As defined by Technical Specifications for the Vermont Yankee n..,.1. o r pnuar gration Sactinn A.7.3.1. up nre renorrina the followino '

sumu t ma t vetutteuce ao nu-DI*, and evuflamius uut olsekuu conversation with your office.

At approximately 1400 on August 16, 1973, an instrument technician, while investigating a reported opening of the Pressure Suppression Chamber-Reactor Building Vacuum Breakers, discovered that the instrument Jines monitoring suppression chamber pressure were incorrectly tubed g to the dif ferential pressure sensors which activate breaker operation, 3 thus causing actuation with positive suppression chamber pressure. This inoperabili ty of the Pressure Suppression Chamber-Reactor Building Vacuum Breaker s- m exceeds the Limiting Conditions for Operations as defined by Section . 7. A.3.a of Technical

• Specifications . The subject section requires that two of tvo vacuum breakers shall be operable at 'all times when primary containment integrity is required.

The instrument line connections to DPIS 16-19-32A and,B were immediately corrected and returned to service by 1430 on August 16, 1973.

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COPY SENI' REGION 4

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- k.,), VERMONT YolKCC NUCLCAR POWER CORPORATiod I

Directorate of Regulatory Operations

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August 17, 1973 I Page 2 ,

All other dif ferential pressure sensors are being investigated te ensure that a sin.ilar condition does not exist elsewhere.

Very truly yours, VERMONT YANKEE I.1] CLEAR POWER CORPORATION

""" 3 s.yc George S. Thomas Assistant Plant Superintendent WFC/kbd t

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