05000263/LER-1976-018

LER 76-18:on 760909,investigation of Drywell Torus Pressure Differential Effect on Torus Water Level Vol Correllation Disclosed Vol Slightly Below Tech Spec Limit.Water Vol Increased & New Vol Vs Level Correlation Issued

ML20056B851
Person / Time
Site:	Monticello
Issue date:	09/22/1976
From:	Clarity M NORTHERN STATES POWER CO.
To:
References
LER-76-18, NUDOCS 9102130429
Download: ML20056B851 (1)

LER-2076-018,

Event date:
Report date:
2632076018R00 - NRC Website

text

_ _ _ _ _ _ _ _ _ _ .

UCENSEE EVENT REPORT 1 1

CCNTEOL BLCCK:( l l l l l l [PLEASE P21NT ALL t'EQUIRE3 tNFOIMATION) 1 6 l NAME LCENsE NUMBER E Tv E '

o' 7 e9 lMi xl 4xlPiil 14 10101-10 l 0 I o 10101-10 lo i I4 11 11 11 11 I 15 25 26 30 b i 11 31 32 l

CA1EGony "'$U Tp fsYE coCxET NUMBEa EVENT CATE REPORT CATE

@ CONT l 7 8 57 l

58 l [T_]

59 W60 l Ol 5l 01-l012 l 6 l 3 l 61 68 l O l 91 0l 91 7l 6l 69 74 l0 l 91212 l 7 l 6]

75 80 EVENT DESCR6PTION o l LURING NORMAL CPERATICN, INVESTIGATION OF DRYWELL-TCRUS PRESSURE DIFFERENTIAL l 7 89 60 c3 l nrrm ny TnonS WATrp irypt .vntituc mapri ATTON DTsrinsen VntWn si TmTTY PFinW Teru l 7 89 60 Q l SPEC. LDlIT. LEVEL IDWERED SLIGFffLY ON 9-7-76 IN RESPONSE TO RECENT NRC DESIRE TO l 7 89 OJ <

@ l STAY CLOSER 'ID LON LIMIT. CORRELATION USED DID NOT ACCOUNT FOR WATER DISPLACED FRnN1 j I 7 89 60

[]31 VENTS DUE TO PRESSURE DIFFERENTLAL. NO REDUNDANT SYSTB1. l l 7 89 mg 60 C E COCE CCMPONENT CODE R VOLATON o lS I A l lA l l zl :l z l z l z l zj lz l lzl9l9l9l y 7 89 10 11 12 17 43 44 47 48 CAUSE DESCRiPTON f l FAILURE TO ACCOUNT FOR FFFECT OF DRYWELL. TORUS PRESSURE DIFFERENTIAL kHEN SPECIFYINGJ ,

7 89 bJ j DFSTRUD TODMS KA'ITD T RTT WATED VntTTNm WA9 TNrDP ACrn AYn A VFW Vnif f"; V9 i nTi j 7 89 tsd 1

l CORRELATION WAS ISSUED. J

's'[Ev's' s conta oTsEn status "!s'Co C vEay oiscovEnv cEscamTON 1

9 W l1l 0l 0l l NA l W l Investigation l 7 8 10 12 13 44 45 46 80 ACTMTv CONTENT AELEAsED OF AELE ASE AMOUNT OF ACTMTv LOCATON CF RELEALE M p_j [:_j l NA l ' l NA l 7 8 9 10 11 44 45 60 PERSONNEL EXPOSURES NUMBER TYPE DESCaiPTON 1

7 89 l0 1 0l 0l 11 Wl12 13 NA

• 60 j

PERSONNEL INJURIES '

I NUMBER DE SCAPTON . I El l0l Ol Ol l NA l 7 89 11 12 BO OFF5ITE CONSEQUENCES 1 l NA J 7 89 60 LOSS OR OAMAGE TO FACILITY T Y PE DESCRPT ON E9 L:J 10l NA 7 0S I ,

. 60 i PUDLICiTY M L NA 7 89 80 l

AOCITIONAL FACTORS M l (EVD.T DESCRIPTION CONT'D) NO PREVIOUS SIMILAR OCCURRENCFS. VOLUME INCREASED l 7 89 80 9102130429 760922 CF ADOCK 050 63 DE l A50VE LIMIT. 81-RO-76 18) l 7 89 _. 80 NAME. M. H. Clarity moNE51.2 g95-5151 4 we ees.ser. }

3 l

.') l HSP NORTHERN STATES POWER COMPANY M IN N E A P O Li s. M IN N E S OTA 5 54 01 l

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.C  %

Qg K' s September 22, 1976 &, (( +

1 seper s Mr J G Keppler, Director, Region III k WI ~

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Office of Inspection & Enforcement C3 U S Nuclear Regulatory Conraission g 799 Roosevelt Road D Glen Ellyn, IL 60137

Dear Mr Reppler:

MONTICELLO NUCLEAR GENERATING PIANT Docket No. 50-263 License No. DPR-22 Torus Water Volume Below Lim,i_tit The Licensee Event Report for this occun;-..;. x. reproduced on the back of this letter. Enclosed are 3 copies.

Yours very truly,

}t'j-L 0 Mayer, PE 4 f c 7, Manager, Nuclear Support Services < i; / -

LOM/MHV/ deb 1. f m v' /,

cc: Director, IE, USNRC (40) y ((;y 'C '

. Director, MIPC, USNRC (3)

G Charnoff f

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(j t

i MPCA Attn: J W Ferman b\', 5> ;s i

f 3L" l** ,

'%+ Men Ye'5 I

% . n _. s '

9778

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Nbh i N O Ft T H E R N STATES POWEn CO M P A-- N--Y -

14 ant. ice 33o lhc3 ear Generating P3 ant j lenticeJIo, )M MG62  ;

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l 1  !

j Sc}itutier 30, 1976 ,ji l IU  !

l 14r. J. G. Kcppler, Director i Region 131

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i Office of 3nspect. ion and linforcen. cat  !

l Unit a3 States Ibt3 car llegulato e Co: mission j j 799 Roosevcit Rond .

i G3 cn li3 3 yn, 3 3 3 inois 60337

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l Dear 15. Xcppler'

• 1  !

1x3rr3cnto meumR cumurIle PLAh5r i Doche .16. 50-263 License 16. DPR-22  :

! i d

On Sepictaber 9,1976, it was Comri that toms water vo3ume sets severa3 Intn-  !

< diw3 cubic feet be.3ow the 6tt,tJ10 cubic foot miniman rco,uired by TecJmica3  !

4 Specification 3.7.A,3 (c). *1brus imf.cr 3cyc1 Ind been reduced slight 3y on-  !

Septernher 7,1976, in response to recent3y expressed WRC desire that )cvel  ;

be raa.intairied closer to the Jov

Jimit to minimiz,e structural lottds during l 7 a IDCA. 7Tre correlation between voltrw: and indicated Icyc1 wldch vns used l J to establish the desired IcVel had not been corrected to account for water l 4 displaced Mm the vent downconiers due to the drpeel) - torus pressure diff-  !

i crential.  !

~

1 j tlpon discovery, the seter vo3une vas increased to slightly above the Jinrit,  :

1 and a new volume vs Jevel corrc3ntion was issued. j

Yours veni tru3y, 4

l ,6 2 . ,7 czy?

f #1'bi. .( .

l- L. R. F33ason >

PJant. Harager l IE/sdd cc

llirector, Office of }4anagement ' Jnfornetion 6 Program Control (2 copies) .

G Charnoff I

}4innesot.a Po33ution Control Agency Attn: J W Periwm

i F33c

{ [9py nent by tc3cc9 pier _to Kc191 cy:

D W

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