ML20126A603

RO 2-80-2/1P on 800110:leak Testing on ADS Safety Relief Valve Air Supply Piping Identified Check Valves in Piping Exhibiting Through Leakage in Reverse.Caused by Inappropriate Design.Unit 2 Shut Down for Piping Insp

ML20126A603
Person / Time
Site:	Peach Bottom
Issue date:	01/11/1980
From:	Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:
References
NUDOCS 8002150122
Download: ML20126A603 (2)

Text

l PHILADEl.PHIA ELiiCTRIC COMPANY '

i Poach Bottom Atomic Power Station bolta, P c n n s y a v:e n t ns j _

L13th January Jl, 19s0 Mr. boyce n. Grt a r Office of inapuction and Enforecuent Region 1 i United States Nuclear Regulatory Coumission 631 Park Avenuo l King of P r u a r, i a , PA 19406 i S ti nJ ECT : R E P O M T A ti L E OCCU R R EN Cli . P RO*4 P T NOTIFICATION 'l

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Con fi rmin g W. T. 011 rich's conversation with Mr. Grounman,

' Region 1, United Stato. Nucicar uegutatory C o wim i a z i o n on January 10, 1960.

R e f o r u n c e :, Docket No. 50-277 and 50-278 l Peach Buttom Unita 2 and 3 Technical Spe ci fi c at i on Reference >: o.9,2.a(9)

Ruport Nu, 2-50-2/!P Occurrence Date, Janua ry 10, 19 ts o i Identification of Occurrence:

Misapplication or a hard seated chuck valve in the ADS safety reliof valvo .ir s u p p.l y piping.

Apnaren- Cause of Occurrence:

In a pprop ri a t s design.

Analysis u_f Occurrunce: ]

l Leak tostang on the Ais S >afoty-4oisaf va1vu alr uupp1V p161ng l identified chuck valves in the pipanu that ornibited through-loakage an tne rov e rs e ( e tt e c k i n g ) direction Each chock valve lholutos an ADS mafety-reliof valvo air operatur and I L ., a a m o c i a t, u d str accumulator froni t. h e air supply s y s t u as . The air piping at the con tainment punotration and the piping at the ADS safety-relief valvon 13 designed solAute C l a n :, l' . n 'l t h o u g h the tutorsenton pipin, in the dryaoll was not doaigned as s c i a m. l c Cluss 1, it la all small piping not subjected to large torces during a seismic ovent.

The air s upp ly :.ys t em e x t.e rn a l to thu drywell is not seisale Clu.ss I ti t t.h the lomkage of tne att from tit e accumulators through the hard seated check valve, long term upc4abiltty of the ADS s, n i e t y - r e l i e f valveu cannot ti o aa,surud. Thi. n. a y complicate the couldown of the ruautor in the event. o t' an carthquake. c o u.ti a n e d with a total losa of off-site po.or, The AUS lunction af thouu - valvus during a small break L.O C A whuru tiP C ) 23 i n opu r a b '! c 1. not affected because they asi used carfy in t. h e transient befuse thu Joakage can affect their operability.

3 8002150

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.. 2 Corrective Action: l Unit 2 has baan shut down fo r inspnction or enn p t s. i n c i n a t ele the

! drywell ro determine acismic class and to replace the h a rit w an t ant  ;

check valvas with soft s ea t eil on e s , fin i t 3 hn* bnen esi n i p p c<l with j a se.lsmic Class t backup supp.ly external to t. h e d rywe l I at the containment penetration to ensure the capeibility o f ADS s a f e t y - r e l i e f' )

valve operations fo r an e x t e n d ait p e r t oil of time in the event _of u <

total loss of outside power coupled with an earthqunie. If the inspection of tin i t 2 reveals.that the intervening air supply system within the drywett is not seismic Class T. Unit 3 will be shut down to replace the check valves.

Previous Faltures:

None.

Vary truly yours.

}7~J Xgg*X.*... . Lf N. T. Uttrich Station Superintendent WTU:lla

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