ML19312B758

RO-2-79-49:on 791005,insp Program in Accordance W/Ie Bulletin 79-02 Revealed Design Deficiency in Four Seismic Supports Associated w/1-inch Control Rod Drive Piping. Bechtel Corp Redesigning Supports within Acceptable Limits

ML19312B758
Person / Time
Site:	Peach Bottom
Issue date:	11/02/1979
From:	Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:
References
IEB-79-02, IEB-79-2, NUDOCS 7911190342
Download: ML19312B758 (2)

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I'll11,ADFt.Plf1 A El.F'CTHIC COMPANY Pench Bottom Atomic Power 8tation (Ig a. h (f Delta. Pennsylvania 173118 November 2, 1979 Mr. Boyce 11. Orler Office of Inspection nnd Enforcement Region 1 United Dt.at.on Huvicar Roguint.ory Commi ssion I G u Park Avenue King of Prunnin, PA .19706I 4 i THIS DOCUMENT CDNTAI pgR QUAUTY PAGES DUJVECT: '-

ItEPORTABL.E OCCURREllCE - PROMPT NOTIFICATION ]

Confi rmine, W. T. III .i rJ ch' n convorantion with Mr. nreenman, Dcgfon .1, United fitnten Nuclear Reguintory Cornianlon on November 7, 3979

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Ileference: Ikacket. Hn . % -277 Pcnch let tom Un i t ?

, Technien1 flyecifient,lon lieforencon: 6.9.P.n(9)  !

Report. Ho.  ?-79 b9 Occurrence Datet October 5,1979 l

Identifiention of Occurrence:

An part of t.he innportion program which in being parformed .in ranponse t.o l NHC Thal Jotin 19-02, on ons s incering revlaw of vendor dec.lgn revenind n i non-connnevntive condi t.f on existit.g vj th la ceinmic nupports annocinted vjth T Contro.1 flod Dri ve piping. This piping runn from the Control Rod Drive ifydrnulle Control Unitn in the Reactor IN11(ling t.o the Control Rod Drivan. Four of the nix nnchor bolta on each Hupport Vere found to hnVG a design Hafet,y IRetor hetVeeng 'l nnd 2. } j Apparant Caupo of Uecurrenoot Engineer 1ng design dericiency.

Ann.lynis of Occurrence _:

Although n nnfety fnetor for ench of the h supports van not nvn11nble, engineering , judgement indiented that the nafety factors would be between 1 nnd 2. Post.ulating the design basin earthquake, rn13nre of thene selpmle nupports and pubnequont failure of the supported piping would not, prevent the Control Hodn from scraraming.

Corrcet.lvo Action:

Bechte 1 Corporation is prennntly redesigning tha supporta to rnine the enfety fact ora of a t3 h neinmic nupports to acceptable 31mita. Thir snodt ficntion vill be f rnplemented within 7 anyn. Fni) ure to impinrtent corrective action within thin titse period vill rerguire Unit 2 to be pit.ced in the cold chutdown condition (reference letter from B. H. Grier, Director, ITRC, Henion 1 to II . T.. Daltrof f, Vice. Pren. , Electric Product t on dat.ed Oc tnber Pis , 1979).

79111903 4

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Previous Failures:

2-79-33/IP 2-79-35/3P 3-79-19/J P 3-TV-73/IP 3-79-25/IP 3-79-26/IP

' 2-79-%/IP 3-79-30/1P 3-79-31/.1P 3-79-3?/IP 3-79-29/]P Very truly yourn, NY ffAd$ 1-d '

W. T. Ullrich titntion Superintendent, Wnl:ent i

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