ML20086K286

Telecopy AOs 74-55 for Unit 2 & 74-32 for Unit 3:on 741127, Four Excess Flow Check Valve Bypass Valves Discovered in Open Position.Caused by Improper Procedural Control.Test Procedures Being Reviewed & Revised.Open Valves Closed

ML20086K286
Person / Time
Site:	Peach Bottom
Issue date:	11/29/1974
From:	Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
AO-74-32, AO-74-55, NUDOCS 8401260435
Download: ML20086K286 (2)

Text

r o e P!!1LADr.l.Pil! A r.LT.CTRIC COMPAYY f'b I

• o ~

'ench Bottom Atomic Power SC lon Delta, Pennnylvnnia 17314 1;ovember 29, 1974

r. Jneen P, O'Reilly. Director nited Staten Atoete Energy Comaionion @~ g gg pg r ci ,,

.rcctorate of Regulatory Operations jf g (Oh4P 88##MUN 31 Park Avenue ing of Prunnia, Pennnylvania 19406 . . . _ _ .

7jects b _ Abnormal Occurrence 24-Ilour tiotliication

.:nfirning W. T. Ullrich'n phone conversation with !!r. Valt Baunack, A.E.C. Region 1

culatory Operationn Of fice on 1;ovember 27, 1974.

.:ference: License Number DPR-55 and 50-278-74-32 Tcchnical Specification Parantaph 3.7.D.2 .

_ . . - _ . . . ____.,_....m .

. . . = - -

port No.: 50-277-74-55 and 50-278-74-32

port Dato: Novenhcr 29, 1974 heurrenco-Dato s Nove bar 27., 1074 - - . . . - - -

bcility: Peach Bottom Atomic Poucr Station Delta, Pennsylvania 17314

(:cntification of Occurrence:

Discovery of four encens flow check valve bypnen valven in the open pooition.

2nditiono Prior to Occurrence:

Unit 2 at approxinately 100% and Unit 3 at appronicately 507. power.

accription of Occurrence:

During the investigation of an instrument probica, coveral instru=ent nencias lines were

( =..CI:;c 99..inR qt5o r.t .Jdt-.$Mntifr ro ~.11h1c - 1 e nh o, Dn.qtv1 ?)cip.J.uvytI p innyip y g sy g fl~od chech valvo bypaca-valvaa aar.ociated with Unit 3 incert :entation ucrc'.found in--coa.

op:n position.

signation of Apparent Cause of Occurrence

Improper procedural control on excesa flow check valve bypass valve.

alysis of Occurrence:

Th2 instrument sensing lines are provided with a rootricting orifice innido the dryucil, a nnnual chutof f valve outsido the dryuolls and an exccos flou check volve icacdintcly downstream of the shutoff valvo outcido the dryuell. Each excess flou check valve has a bypass valve which is opened during reactor vcusc1 hydrostatic testitt3, integrated leak rate testing, and local icak rato tecting. The bypnaa valves on the exccan flow chock valves should nortally be cloced during reactor power operation. The instrunent censing lines are n=all dimeter piping which nico tend to linit flov. Total leakage on a ruptured instru= cat lino would bo li=ited by the upotroom orifice with the exceso flow check valve dicabled. Sinen leakago is limited by another in-lino devico and no piping failurco have occurred, the safety iap11 cations nosociated with thic event are etnical.

rrective Action:

Ao indicated above, the excess flow check valve bypass galvengen opened during the p$rforcance of certatu tents. The present procedurco yaedst'o y,cr[ bra thene teute do not include n detailed check liet which verif ten that;gNOMMOEt('21ov check valve bypass valve han beca returned to the cloned posttion af5M$o5piction o,fg cccting. It is believed that the non-existanco of cuch detailed check listg ($2 bedthe bypass valves to bc Icft in an open position.

g6- f/ r OW3 st .. .

8401260435 741129 PDR ADOCK 05000277

/9 W**

S PDR

, +,.

~

~' ~~

. .. O w C g pbnoren1 Occurrence 24-11our Report _ _50-277-74-55 _nnd__5_0-_278-74-32 .

Af ter noting the above 4 valves in an open ponition, all excess flow check valves in both Unit 2 and Unit 3 wert. checked. This inspection revealed two addition.11 bypann valves on Unit 2 and two additional bypana valves on Unit 3 in the open position. All other valves were found in the closed position. The valves which were found open were irmediately closed.

The applicable test procedures are being reviewed and revised to include appropriate steps which verify that the exceos flow check valve bypass valves have been returned to the closed position af ter co:cpletion of the test.

Failuro Data:

j Abnornal Occurrence Report lio. 50-277-74-35 and 50-278-74-10. -

rvary truly yours, ,

l f*W.* AS"~ f. .

st. T. Ullricli, Superintendent e Peach Bottca Atomic Power Station ,

i 5

a 4

e e

4

<_. _w