ML20086J068

Telecopy AO 75-6:on 750121,RSCS 30% Rated Power Interlock PS-3-3-250A Failed.Caused by Minor Leakage from Bourbon Tube Resulting in Buildup of Moisture in Switch Case.Switch Assembly Replaced,Calibr & Checked

ML20086J068
Person / Time
Site:	Peach Bottom
Issue date:	01/22/1975
From:	Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20086J066	List: ML20086J065 ML20086J068
References
AO-75-6, NUDOCS 8401230093
Download: ML20086J068 (1)

Text

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% 6 PL $ $. U. y -WWC6d. 'W.

O -it he-a Peach Bottour Atomic Power Station Delta. Pennsylvania 17314 January 22. 1975 Mr. James P. O'Reilly Director United States Atomic Energy Cossaission l Directorate of Regulatory Operations 631 Park Avenue King Of Prussia, Pennsylvania 19406

Subject:

Abnormal Occurrence 24-Hour Notification Csafirming R. S. Fleiscimann's phone conversation with Tom Shedlowsky, A.E.C. Region 1 Regulatory Operations Of fice on January 22. 1975.

Reference:

License Number DPR-56 Technical Specification

Reference:

3.3.B.3.a c i

a ss'??// s\

Report No.;

Report Date:

S0-278-75-6 January 22, 1975 [ ~N) h,.a

,g[yp, u/.s Occurrence Date: January 21. 1975 2 @tf N Fccility: Peach Bottom Atonic Power Station --k R.D. 1. Delta, Pennsylvania 17314 ID 4 ,'? O ,.. //'/,D

' A' ~i c: .,L. , . ~6 Identification of Occurrence: q 47,'f 'f,Cl.

Failure of P5-3-3-250A, RSCS 30% rated power interlockE kY. Y cedician. Prine en (k currence:

Unit 3 shutdown.

Description of Occurrence:

During a routine instru: ment surveillance test, PS-3-3-250A was found to have suffered corrosion damage which rendered it inoperable. The corrosion resulted from a buildup of noisture in the switch housing.

l Designation of Apparent Cause of Occurrence:

Minor leakage f ron the bourdon tube resulting in a building of moisture in the switch case.

Analysis of Occurrence:

accause either the PS-250A or PS-2503 switch servea independently to arm ths RSCG -

. lielov. 30% rated power, the failure.of only one of these evitches han einisal safet; implications.

Corrective Action:

The entire switch assembly was replaced in kind, calibrated, and checked in accordance with the applicable surveillance test.

Failure Data:

None previous. g123OO93750131

. g ADOCK 05000278 PDR Very truly yours, 9 13 W. T. Ullrich, Superin*,endent Peach Bottom Atomic Power Station

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