ML20086J204

Telecopy AO 74-27:on 741121,main Steam Relief Valve RV3-71J Unexpectedly Operated.Caused by Ground on Control Cable to Relief Valve J Manual Actuation Solenoid.Leads Lifted to Manual Actuation Solenoid

ML20086J204
Person / Time
Site:	Peach Bottom
Issue date:	11/22/1974
From:	Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20086J203	List: ML20086J201 ML20086J204
References
AO-74-27, NUDOCS 8401230312
Download: ML20086J204 (1)

Text

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-~ ~ *Melfication Confirming R. S. Fleiscl= sun's conversation with Mr. title Eaunack, A.E.C. Region 1 Ibgulatory Operations Office on Novanber 21, 1974.

Refcresce: License Number DPR-56 Technical Specification Reference 3.6.D.1

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Occurrence Date: November 21, 1974 F cility: Pecch Dottom Atomic Power Station R.D. 1. Delta, Pennsylvanic 17314 Idcutification of Cccurrence:

Unexpected operation of Main Steam Relier Valvo RV3-71J Canditions Prior to Occurrence:

Unit 3 at appro icstely 35% power.

D scription of Occurrence:

At approxt:.stely 35* power with stable plant conditions, the "J" relief valve opened droppin; plant electrical load by about 70 HU. This occurred twice within o few nicutes.

Decignation of Apparcat Cause of Occurrence:

Ground on the control esble to the "J" relief valve manual actuation solenoid.

Anelyais of Occurrence:

Decnuno this valve in not part of the ADS (auto blevdown) syctem and because the feilure and cubsequent. 11ftin:l: of leads af fcceed only the capability of manually cperating tha relief valve from the control room, the safety is:plications are ninimal.

Carrcetive Action:

Investigation shoved that one side of the relief valve t.:nual actuation solenoid was solidly grounded and that there s.as a concurrent intornittent ground on the d.c.

cyates supplyin2 control power to this valve. This combination of grounds had been ecsponsible for the unexpects.d operation of the relief valve colenoid. Because this was not an A.D.S. valve, the 1cade vore lif.ted to'Ethe manual 4.ctuation solenoid, re oving only the c.anual actuation capabilit?,yj.gd. ground vill be furthsr investigated cnd corrected when practical. WM Failure Data:

l Ho previous failures of this type. g gg g Z ON Nb Vcry truly yours, 4.. 03M3D

/*' h&s .* f W. T. Ullrich, Sups-intendent Peach Dottem Atomic Power Station 8401230312 741201 PDR ADOCK 05000278 6 PDR