ML20086J381

Telecopy AO 74-12:on 741004,setpoint Drift on RCIC Turbine High Reactor Water Level Sensor Found in Direction Less Conservative than Specified in Tech Specs.Caused by Binding of Wheel on Cam Follower.Cam Follower Assembly Replaced

ML20086J381
Person / Time
Site:	Peach Bottom
Issue date:	10/07/1974
From:	Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20086J376	List: ML20086J372 ML20086J381
References
AO-74-12, NUDOCS 8401230624
Download: ML20086J381 (2)

Text

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October 7, 1974 Mr. Ja:es P. O'Reilly, Director

c. 4 .-a. .

King of Prussia, Pennsylvanin 19406 Subj ec t : Abnor-al occurrence 24-Hour ':otification Confirning L'. T. U11 rich's phone conversation with Mr. k' alt Baunack, A.E.C.

Region 1 Regulatory Operationc Office on October 4, 1974.

Reference:

License Sunber DPR-56 -

Tec'mical Spnification Reference Table 3.2.B Report To. 50-278-74-12 --

Report Date: October 7, 1974 Occurrence Date: October 4, 1974 Facility: Peach F, otto: Atomic Fover Station R.D. 1, Delta, Pennsylvania Identification of Occurrence:

Setpoint drif t on the RCIC turbine high reactor water level sensor in a "

direction Icsc conservative than specified in the Tachnical Specifications. . .

Conditions Prior to Occurrence: ,

Unit 3 Start-Up, reactor critical, reactor pressure less than 200 poi.

Description of Occurrence: ..

During a routine instrument calibration surveillance test, the setpoint of one of the RCIC turbine high reactor water levc1 senr. ora, LIS-3-2-3-101A, was found to have drifted outside the limit called for in the Technical ..

Specifications. The prescribed setpoint for this device ia {45". The device was found to trip at 45.1".

Designation of Apparent Cause of Occurrence:

The wheel on the ca: follover was found to be binding, requiring greater

notion on the can to trip the svitch.

A:ulysis of Occurrence:

Since the actpoint shif t was cinor, and would not have prevented the sensor f rom providing a high level signal to the RCIC turbine trip logic, - -

this occurrence has minira1 saf ety implications.

Corrective Action: -

The can follower assembly was replaced; setpoint adjusted and checked for --

repeatability; and the instrument functionally checked per the applicable surveillance test orior to returning it to service.

8401230624 741014 PDR ADOCK 05000278 S PDR < .i.c

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O O l

t p Failure Data:

l These differential pressure avitelgen have required frequent l

re-calibrations to correct actpoint ohif tn. Since the start-up of Unit 2, setpoint shif tu on the instruments in this riorvice have required recalibration on 24 oceacions. Shifts to values in exccas of Technical Specification linien occurred air, times including thin occurrence. Most of these deviations vere only slightly beyond the required setpoint and did not constitute a safety hazard.

Very truly yours, ffffkY W. T. Ullrich. Superintendent Peach Ecttom Ato:ic Pouer Station 9 9 9 #9* +=44eeea e en 4 e e g i

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