ML20086K905

Telecopy AO 74-29:on 740528,recirculation Pump Switch DPIS-2-2-137A Failed.Caused by Failure of Differential Pressure Cell Bellows Mechanism.Device Will Be Replaced W/ Spare

ML20086K905
Person / Time
Site:	Peach Bottom
Issue date:	05/29/1974
From:	Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20086K904	List: ML20086K901 ML20086K905
References
AO-74-29, NUDOCS 8402070068
Download: ML20086K905 (1)

Text

. d' 'Direclorate of Regul y Operations d'W T;i W 631 Park Avenue My King of Prussia, Pennsylvania 19406 *% ;:; .

f@d; Subiect: Abnortul Occurrence 24-Hour Notification e'-

.h &.R.

Confircing my conversation with Mr. Donald Cathton, A.E.C. Region 1 it;- '.4 s ,.

Regulatory Operations Office on May 29, 1974 'p._v. $.fN ~ . .Q

Reference:

License Number DPR 44, Amendeent Nu=ber 1  !.kf [hk)

Technical Specification Table 3 2.3 ((19

.a.s .::9 .

Report No.: 50-277-74-29 .d!h. g Report Date: May 29, 1974 ' *b O,% c' Occurrence Date: May 28, 1974 RM7?

Facility: Peach Botto: Atomic Power Station .~~

R. D. #1, Delta, Pennsylvania 17314 Identification of Occurrence:

Failure of the recirculation purp a p avitch dPIS-2-2-137A. -

Conditions Prior to Occurrence:

The reactor was critical at 65% power, 960 psig.

Description of Occurrence:

During a routine functional curveillance test the subject differential -

pressure switch failed to operate. This switch provides an input into the LPCI break detection logic circuit and has a Technical Specification -

setpoint of 2 + 1 psid. 'ihen the device was valved out of service and the 3 -

Ap reduced to zero psid, the indicator and trip mechanie= remained at about 7 paid.

Designation of Apparent Cause of Occurrence:

The differential pressure cell bellows cechanism has apparently failed. .

This failure prevents the trip and indicator from following a change in -

pressure.

Analysis of Occurrence:

This failure has minimal safety inlications since ihe logic circuit in which this switch is connected is of the one-out-of-two-twice type ,

and is also redundant in the other LPCI system. . - _

Corrective Action -

For other reasons the plant was shutdown on 5/29/74 The device chall be .

A replaced with a spare prior to returning the plant to service. The failed device will be disassecbled to deter =ine, if possible, the cause of the -

failure.

Failure Inta:

This is the firct failure of this type on evitchen in thic service.

f $

Very truly yours, pg - -

W. T. Ullrich, Superintendent ' '-

E Peach Bottom Atomic Power Station ,

> u 2 8402070068 740607 E , b PDR ADOCK 05000277 h 3:

S PDR 3R r m

-*