ML20086J167

Telecopy AO 74-34:on 741207,hydraulic Snubbers Found Inoperable on Main Steam Relief Valve Discharge Piping. Caused by Loosening of Lock Nuts.Snubbers Repaired

ML20086J167
Person / Time
Site:	Peach Bottom
Issue date:	12/09/1974
From:	Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20086J166	List: ML20086J162 ML20086J167
References
AO-74-34, NUDOCS 8401230274
Download: ML20086J167 (2)

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VILADPLPi!1LELECIP.1C..C0!C'A( qg g(

Peach Eo tton Atomic Power S ta tiva). . D ,", g--

Delta Pennoylvanin g , v.; O t ? D O *d D .C

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Decenber 9, 1974 Jttm.clLL _0'.ACllly .J)i. rect _or zed States Atomic Enargy Comincion setorate of Regulatory Operations Park Avenuo .

7,of Prunoia, Pennoylvania 19406 d cc t_t Abnoral Occurrence 24-Itour Natifiention tfircing H. T. Ullrich'a phone convernation with Mr. Walt Daunuck, A.E.C. Region 1

ulatory Operations Of fico on December 8,1974.

crence Licence !; umber DPR-50 ,

Technical Specification

Reference:

3.11.D.1 b,  !

ort !!o.: 50-278-74-34 O

sort Date: Decenber 8, 1974 f

urrence Date

Decenber 7, 1974 i

ility: Peach Lotton Atomic Power Station, Deltn, Pennnylvania 17314 ,

n/ I entifiention of Occurrence:

Inoperabic hydraulic anubbern on tuin ocean relief valve discharge piping. <

uditions Prior to Occurrence: ,

l Reactor nhutdown.

acription of Occurrenec:

A routine inspection of / Unit 3 dryvcll hydynulic anubbero during an outage identific uin unubbern on tha rctin etcan relief valve diccharge pipin:: uhich vere Inuperi.blo.0no caubber on RV-71E (3-1-G';-s-2) cal ny-71J (3-1-GG-S-0) diccinrge lineo ucre found to La rotnted cuch that the reservoir vao belou t.he hydraulic cylinder. Pour snubbera on RV-71F dincharce line vore found to be inoperable becanoe of the following reunona.

One reecrvair van capty (S-68) . The thrended extennion to the cylinder on one nnubber d

(3-1-CG-S-10) was bent about 15' and tha rccervoir was noved out of pooition. The rccervoir on thic onubbor une alca cc:pty. Snubber S-69 failcd ac the point uharn the picton rod cunnects to the pipe cicep. The pipe clamp had nico noved down the dicchr.rne ;

lino appro::ir.ately one . foot. The fourth cnubber (3-1-CG-S-9) faile.J nt the point uhurc the rod end attcches to the piston rod.

nignation of Apparent Cauce of Occurrence: -

A lock nut ic provided on the cylinder .cy. tensions to unintain the naubber acccmbly in :N proper orientation. Loonening of thio lock nut pornico the naubber to rotate to the inverted position. It in believed thct on tha tuo snubborn which vere found , inverted, the lock nut vibraced loone. The f ailuro of the varioun snubberu on the 'F' relief vela diccharge piping in under invootigation.

f clycio of Occurrenco: .

An inapect. ion of the af f ected piping ton indiented under Corroc81ve Action, Ins not identified any piping dnce:ge. No diccharge of-_ctem to the dryvell roculted f rou the enubber deficiencies. Safety implicacions are, thereforu, ninical. l 1

orrective Action: ,.

.I Repairo voro endo to the 01: tmubbarn noted. The pipe clar:p vae reponitioned and eights All sis: onubbern ucre rer:oved. Ono cylirder anocably vao replaccd, and one rod -er>3 l cttachnent van repnited. The dccaged cylinder c::tcasion and eccervoir support ucre  ;

re traight ened . The icek nuto and nutn and bolto were tightened au required. The anubberl uero filled, tested, and reinstalled.

8401230274 741217 PDR ADOCK 05000278

• 50" '

8 PDR ~

r ,#< , 12M 3s

, 00PY SENT REGION _

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norral Occurrence 24-1 bur Motifiention ncport No. 50- 270-74-34_

The lock nuto on n11 anubbern in the drywell vere checked an being tight during the outcne. Thin ohmild preclude future inverted unubbero.

A volunctric and surface inspection of the A 'F' relief valvo piping from the rain etenta header to the valve in in proa,rcos. curface innpcction on the relief valve dicelurgo piping at each olbou to alco in pronrcoo. An Ennineering is being conculted ci:.h recpect to additional inapcction requirecente. onnineering revicu of the cupport cycten ior chia particular dicchargo line io being rede.

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ilure Dato: . . - . -- -

Av. .wroccurecuernoporc-Tusin'rr SOr27C,74:G; SO-270-74 1G dar30 277-74-45.

ry-truly youra, .

'. PQ ffba T. Ull' rich, Superintendent *

.ach l'otton Atomic Peucr Station.

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