ML20086K540

Telecopy AO 75-5:on 750118,electrical Failure Found of Operator Motor on RHR Throttling Reactor Injection Valve Mo 2-10-154B.Caused by Vibration During Valve Operation. Motor Will Be Replaced & Antirotation Strut & Key Realigned

ML20086K540
Person / Time
Site:	Peach Bottom
Issue date:	01/20/1975
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20086K539	List: ML20086K536 ML20086K540
References
AO-75-5, NUDOCS 8401270230
Download: ML20086K540 (1)

Text

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. P G'd C ln I4 t. l.Dn hl t air. ( c PO We r bl a t. L e nt l O = " ' ' "" " ' " O Jano.iry 20, 1975 Me, Jamen P. O'Reilly, Director Unit ed Stat en Atenic Energy Cor..:ninnion Directorate of hegulatory Operationn 631 Park Avenue Kind of Prussia, Pennnylvanta 19400 .

Subject:

- Abr.orn.il occurrence 24-Ituur ht if f ent ion Confirning T. J. Donnnby's phone ennverant inn with E. J. Brunner, A.E.C. Region 1 Regulatory Operatican Office on January 18, 1915.

Roforence: Licrano 1:ur.ber apR-44 Technical SpecLfication

Reference:

L 5,A.3 neport 30. 50-277-75-5 Report Date: January 10, 1975 Ocentrence nato: Janunty 19, 1975

i'ac ility : Peach Botton Atomic Power Station R.D. 1. Delta, Pennsylvania 17314 Identifi:ation of Occurrence:

Electrient failure of operc tor t;otor on p.!!R throttling reactor injection valve (U.0 2 10-154L)

Conditions Prior to Occurrence:

Reactor chutdoun and depressurized. RllR operating in chutdown cooling tsode.

Description of Occurrence While opening the valve from the control roon, the limitorque operator notor failed electrically, tripping itu circuit breaker.

Dosicnation cf Apparent Cause of Occurrence:

Vibratiur. during valve oporatien had loonened the net ncrew holding the valvo sh:

nati-rotation strut key, The anti-rotation key had niipped down and Jamed betvi the valve nten and the paching follower, rer.ulting in an increaned louding on tht operator. Becauan tlw torque nu'.tch in inoperative during the opening ott'oke, tl cotor failure in probably due to the increaned nochanical lond on the operator.

Analynis of Occurrence:

At the tiee of the failure the reactor wnu in the cold rshutdown condition. The

• RHR loop var; availabl6: for shutdoun cooling, and if required, the "B" loop coul<

have been used beenuse the MO 10-154B valve was in the partially open ponition when the rwtor failed. The unfety significance of this incident in minimal becna the vibration which initinted the failure exf otu only when the valve in being throttled. During reactor operacion thin valve in in the full open ponition.

Correctf.ve Action:

The cotor vill be replaced and the anti-rotation ntrut and key realigned. The m acrou vill be ntaked in place and the other three MO 10-154 valves vill be inspected for loone net ocrcun and anti-rotation struta.

l Failure Data:

There have been no identient failures of thin type nt Peach Botton, but a notor failure on this operator van reported in Abnornal Occurrence Report 50-277-74-32 l Very truly yourn, 0401270230 750128