ML17252A241

Letter Submitting Reportable Occurrence Number 050-249/1976-18 in Accordance with Technical Specifications, Section 6.6.B

ML17252A241
Person / Time
Site:	Dresden
Issue date:	10/21/1976
From:	Stephenson B Commonwealth Edison Co
To:	James Keppler NRC/RGN-III
References
BBS Ltr. #76-748
Download: ML17252A241 (3)

Text

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• . Comrtto~h-h Edison

. DrescP.ln Nuclear Power Station e

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R.R. #1 Morris, Illinois 60450 Telephone 815/942-2920 BBS Ltr. #76-748 oc*tober 21, 1976 Mr. Jame1s G~ Keppler, Regional Di rec tor Di~ectorate of Regulatory Operat{ons - Region III u .. S. Nuclear* Regulatory. Commis*sion 799 Roosevelt Road

• Glen Ellyn, Illinois 60137 Enclosed please find Reportable Occurrence report.number 50-249/1976-18 ..

This report is being submitted to your office in accordance *with the Dresd.en:

Nuclear Power Station Technical Specifications, Section 6.6.B.

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'-B. Stephenson Station Superintendent Dresden*Nuclear Power Statiort BBS:jo

• Enclosure*

cc: Director of Inspection & Enforcement Director of Man~gement Information & Program Control Fi.le/NRC Mail Seaton 0ac.k;;1 Gierk

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. . LICENSEE EVENT REPOA1a CONTROL BLg_i;:K:L ii~,

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(PLEASE PRINT ALL REQUIRED INFORMATION)

UC EN SEE LICENSE EVENT NAME LICENSE NUMBER TYPE TYPE

• • @E] II tLIDIRISl3 I 10101-10101010101-10101 14 I r 11 1t 1t I 10131 1 a9 14 15 ' . 25 26 30 31 32 REPORT REPORT CATEGORY . TYPE SOURCE OOCKET NUMBER EVENT* DATE REPORT.DATE

• @rr]coNI I I I IL I lLI 1015IOl~IOIJl4lql IO Iq I :u I ? I t, I . I I Io I:l Lo I 71 " I 1 a . 57 58 59 60 61 68 69 74 75 80 EVENT DESCRIPTION (0'21 jJ)URl!V(;... '°R.EFtf£UNG OUTAGE UJCAL J...EAK-RA.TE. lt;:STING, F£EpWATE.f< ..GHCK,.

7 8 9 . 80 folal I VAJ...V5 3-. l20 - 5'3 ..4 ANJ:> -0?.A £XHL8 7< 8 9 .

ITED J...£,(U< RATES bl=

'64.? AND.

(,I 6'ol 80 lol41 lscFH RtSPEc.T1yELY (TECH SPt::c: L1MrT:* 2Cf.3WI Sc.EH). A FE.W PAYS &ATER. I 7 8 9 / 80 lo15l8 ITHE5E Cl1ECK VAJ...VES WE'RE PRES$VR12 ED To soo p~1G- 1N P.N ATTEMPT TO I

. 7 9 . . I . . 80 fol61 l*Bt:TTER 'APPROXlt'YlATE:" ACC!J?C:NT CONDITIONS. SUBSl;;QUCNT 'RETE:STING- OF VAL..VESI

7. 8 9 * ** PRME . . ($E ATTAOIEJ)SJ1CT)80 SYSTEM CAUSE . * ' COMPONENT COMPONENT *

• CODE

• CODE COMPONENT COOE SU?PUEA MANUFACTURER llDLATlJN

~ ICIHI lfil IVIAILIVIEIXI lAJ 1Clfol~l51' lY.J

. 7 8 9 10 11 12 17 43 44 47 . 48 .*

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• CAU$E DESCRIPTION * . . * . . .

~ )IH£ JN1TiAl- LI-RI FAILUR~ OF VALVE 3-<l10~S"g-,4 WA~ APPARENTLY CAUSE:]) BY I 7 8 9 . . . ' 80 lolsl lD1R-t IN THE 5E11TttJfr f/R£fl. , L.JHtC/=l RES UL TcT> IN ExCESSI'/£ Disc "'."To.; S~AT *** .* I 7 8 9 ' . . . ' 80

'..;~>;J11PJ IC-LEl+RANC£S: PRES$URI z ING-. THE . VAJ.;V{F;kf.NJ//:l-l'-*VJA-:r£1?,..'-1EFF6:.CHl/EbY;. 'REJf>fJ0£fJ):i~,'i.t¢i.. I 7 . 8. 9 . FACILITY

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• M*.ETHOO OF ($c E> fl. TT. OC. kt;.,..:.

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q . .J££_Tj'. .... _SQ

. .: . . . . STATUS " POWER OTHER STATUS . DISCOVERY' DISCOVERY OESCRIPTiON .

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• 10Io I o Io12I 13I . NA 44 I IBJ 45 AIA . .

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. FORM OF ACTIVITY CONTENT RELEASED OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE fiEl . l6J . ~I~ _______N..._.A_ _ ___. NA 7 a* 9 10 . 11 44 45 80 PERSONNEL.- EXPOSURES

• NUMBER TYPE DESCRIPTION

[!lfil Io 10 Io I. 1KJ . ~'______N__'._ A _ _ _ _ _ _ _ _ _ ___,___ _ _.,---_ __,I

. 1 as ** 11 12 13 so PERS'ONNEL. INJURIES .

. NUMBER DESCRIPTION ffEJ IOI O!OI ~--*V._A_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _..______,

7 8 9 11 12 80 OFFSITE CONSEQUENCES fill] . }JA 7 8 9 80 LOSS. OR DAMAGE TO _FACILITY TYPE

• DESCRIPTION EID 1£J NA : .

7 as 10 80

. PUBLICITY .

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. 7 B *9 80 ADDITIONAL FACTORS

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• 8 9 80 PHONE: £';<,/. ';),_,/,,5°

EVENT DESCRIPTION (Continued) 3-220-58A and -62A yielded leak rates of 20,0 and 5220 SCFR respectively, Since the leakage through valve .3-220-58A was reduced to a value below .Tech Spec limits, no further action was necessary. Valve -62A was disassembled and repaired, Redundant valves were available and operable during unit operation, This is a repetitive occurrence. (50-249/1976-18)

• CAUSE DESCRIPTION (Co?tinued) these clearances sufficiently to permit a satisfactory disc-to-seat seal, Disassembly of valve 3-220-62A revealed that, in addition to having dirt in the seating area, the valve also had worn disc assembly pins which resulted in an impre-cise disc-to-seat alignment. The valve was cleaned, and the disc assembly and seal ring were replaced. Following reassembly, valve -62A was retested, and a leak rate of 1.84 SCFH was obtained.

• Because of the high incidence of initial LLRT *failures on the feedwater check valves, the station is currently reevaluating the method of testing these valves. The significant improvement in LLRT results which are obtained after the valves. have been back-seated with water indicates that the present testing method qoes,not allow an adequate determination of how these valves will perform tinder accident

.. ,, G.OJl~.i. tions. Valves. 3-:220-58A and -62A are 18-inch, tilting disc check valves man-

. . .,,~4'£a;tttlfecf~by.'.Cr1rie** c~irfp~ny.