ML20086K366

Telecopy AO 74-41:on 740919,setpoint of HPCI Steam Line High Flow Sensor Found Outside Tech Spec Limits.Caused by Setpoint Drift.Device Recalibr & Returned to Svc

ML20086K366
Person / Time
Site:	Peach Bottom
Issue date:	09/20/1974
From:	Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20086K364	List: ML20086K359 ML20086K366
References
AO-74-41, NUDOCS 8401270046
Download: ML20086K366 (1)

Text

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Afp LADELPHIA ELECTRIC COMPANY Peach Bottom Atomic Power Station Delta, Pennsylvania 17314 September 20, 1974 Mr. James P. O'Reilly, Director United States Atomic Energy Com:nission 3-Directorate of Regulatory O'pc:ations ,C - [., -.

631 Park Avenue King Of Prussia, Pennsylvania 19406 6[M

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Subject:

Abnor=al Occurrence 24-Hour Notification PMf J.?;., " k Confirming R. S. Fleischmann's phone conversation with Mr. Walt Baunack.

A.E.C. Region 1 Regulatory Operations Office on September 20, 1974.

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Reference:

License Number DPR-44, Amendment Number 1 ___

W Technical Specification 3.2.B hy.]

Report No.: 50-277-74-41 Y.J.Q'],

Report Date: September 20, 1974 #:!c Occurrence Date: September 19, 1974 hg-.Q Facility: Peach Bottom Atomic Power Station + -

R. D. 1, Delta, Pennsylvania 17314 k,p.'.1$

,.,-p'l-Identification of occurrenca: ME "-

ri Setpoint of HPCI ateam line high flow sensor outside of Technical Specification limits.

Conditions Prior to Occurrence:

The reactor was at 80% power.

g Description of Occurrence:

During a routine instrument calibration eurveillance test, the setpoint of one of the EPCI' ateam line high flow sensors, DPIS-2-23-76, was found to have drifted outside the limita allowed by the Technical Specifications. The prescribed setpoint for this 3g a device is less than or equal to 225 inches H 20. The device was found to trip at Q jf 231 inches H20. hg f 4 9jV U Designation of Apparent Cause of Occurrence: W' kM(i'~

[ A careful examination of the subject switch revealed no evidence of binding or other mechanical calfunction. The switch tripped consistently at 231 inches B 0.2 This 3fg,',

setpoint failure is attributed to setpoint drif t only. 9,W '.;',

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Analysis of Occurrence: l The HPCI steam line high flow isolation signal circuitry is arranged in a one out i

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of two configuration. A high flow signal from either of the two differential pressure devices is sufficient to cause an isolation of the HPCI steam supply.  %'h gh,y A d

_ Due to the s=sil magnitude of the setpoint shift and the fact that the device was n.I. Q.

functional,,this occurrence has a minimal effect on plant safety. j0gyk,.,,

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. Corrective Action:

i The subject device was imediately recalibrated to within acceptable limits and

_ returned to service. The calibration of the companion switch was checked and found to be satisfactory. 8401270046 740929 -

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i PDR ADOCK 05000277 .

i Failure Date: S PDR j