ML20084U551

Final Deficiency Rept Re Failure of Cable Connector E5 for Drywell Blower 1A4 at Penetration Ea.Caused by Impurity in Connector Prior to Potting.Potting Compound Removed & Replaced

ML20084U551
Person / Time
Site:	Browns Ferry
Issue date:	06/06/1973
From:	Gilleland J TENNESSEE VALLEY AUTHORITY
To:	Kruesi F US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084U431	List: ML20084U446 ML20084U462 ML20084U499 ML20084U519 ML20084U551 ML20084U609 ML20084U662 ML20084U689 ML20084U853 ML20084U869
References
10CFR-050.55E, 10CFR-50.55E, NUDOCS 8306290114
Download: ML20084U551 (2)

Text

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Mr. F. E. Krucci, Director Directorate of Regulatory Operations U.S. Atomic EnerCy Cornission Vashington, D.C. 20545

Dear t.r. Kruesi:

On 'May 7,1973, TVA notified Directorate of Reculatory Operations Region II office by telephone of what was believed to be a repnrtable deficiency in a cable connector at the Browns Ferry I:uclear Plant. In accordunce with paraEraph 50.55(e) of 10 CFR 50, we are submitting the encleced formal report of the deficiency.

Very truly yours,

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21. E. G111 eland Assictant to the Manager of Power Enclosure CC (Enclosure):

Mr. I!ornan C. Moseley, Director Directorate of Regulatory Crerations U.S. Atomic Enercr Cctaission Region II - Suite 818 230 Peuchtree Street, W.

Atlanta, Georcin 30303 8306290114 740617 PDR ADOCK 05000259 5 PoR l

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BR0": S FEPRY N" CLEAR FLi? T C;1T 1 EEFORTABLE DEFICIE::CY - FIN \L DEFICIE:;CY REECRT FALWE OE' CABLE C0:;'.;ECIOR E5 FOR DRT,lELL ELCWER 1A4 AT FENETRATIO: EA Dryvell blevar 1Ah was in cervice to support the Prica / ,

Contair:2nt Leak P. ate Test. Cn M2y h, 1973, a crcund '

vns detected en hECV chutdevn board 1A. It vac treced ^

- to the cotor control center (MC) feeder co' partment for dryvell blcver lAh. The cc=ce cf the g-cund was traced to the pcVer lead for the dryvell blower. Thece power leads are routed th cu--h electrical penetration EA, connection 25-5E. Further checkirc; showed that a 10,0C0-oh:1 recistc. : e path existed frca 3 phace to the shell cf connector ES (cable half of the connector outcide the dryvell). The connector in cucation had been potted following nc=21 precedures. The connector was cut away fror the cables and vts tested after heatin;;. The resistance path ves then =cacured to to 5,CCO ch=c. After cooling to c2bient temperature, the resistance increaced to 10,CCO ch:3.

The pottin;'; co=cu.i van removed fro = the connector, an1 the connector was retested. The recistance path had chant;ed from lO,CCO olra to 50 tegci'rs. Tnic

• was ceasured at 500V DC vith a pertable ce.ger.

It va: ccncluded that scre i= purity W.3 in the connector prior l Lo pottinc. 1." tar the pcttin; ccrpcu ri was recoved and replaced, the anc:aly no 1cn;cr existed.

Since this dryvell bicuer is ; overed from an ungrounded ,

cyctec, no less of functica vould occur from this cin ;1c grourd. T'.cre are 10 drpeell bicvera installed, cicht of which cre required fer centinued rever creration, but servu no safety function during a desiga bacia cccident.

In order to accure that the other connectors for Unit 1 do not have sicilar defectc, TVA vill =oniter the grourri detector 3 du-ing the trecrerational and startup test

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