ML19305A111

LER 78-038/03L-0 on 781125:during Normal Operation,Drywell Vent Valve AO-1601-23 Would Not Open.Mechanical Failure of Solenoid Air Supply Valve SO 2-1601-52A Prevented Operation of Drywell Vent Valve.Solenoid Valve Was Replaced & Tested

ML19305A111
Person / Time
Site:	Quad Cities
Issue date:	12/15/1978
From:	Hannum D COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19305A104	List: ML19305A103 ML19305A111
References
LER-78-038-03L-01, LER-78-38-3L-1, NUDOCS 7901040139
Download: ML19305A111 (2)

Text

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                 +                                                               LICENSEE EVENT REPORT O.

SNIROL HLOCth l l l l l l l (PLEASE PRINT On TYPE ALL EEQUIRED INFORMATION) 1 6 lo lilE l9ll L lLICfNSEE Q l ACOOL l D l 2 l@!0 14 tv l 0l 0l -lLICEinSE O! 0fautl /tif0 Hl - l 0 l0 l 220 !@l4 26 lI l1' IlTYPC LICLNSE l1 JJl@!b7 GAIl l@ b6 CO%'T loI11 sCM LLJ@l 0 l s 1010 10 l2 l 6 l s l@l i I i i 2 l s l 718 j@li 74 7s I? ii l c l >l a80I@ HEPOHT D S1E l 8 60 61 Dg;gETNUveEH Q$ 63 LVENT D ATc EVENT DESCRIPTION AND PACB ABLE CONSEQUENCES h ' Io i2I l During normal unit operation the Unlt Two operator found he could not open f [ 0,: l [ drywell vent valve A0 1601-23 The valve was left in the closed (safe) position j until the problem could be determined and repairs made. The downstream valves l I n 1. l l lo Isl l A0 2-1601-63 and A0 2-1601-24 were proven operable as required by Technical l j o ic i l Speci fication 3.7.D.2. The alternt,te venting capability of bypass valve A0 2-1601-62l jol7l l was available at the tifne of this occurrence. l I 1018 I I cOI[E '#'d! C0 s sCOoE COMPONENT cOoE su'eCIo'E sEoE 10191 l s l A l@ W@ [3_j h lV l A l L l V l O ! P l@ [[Lj@20 d @ 18 13 7 8 9 to Il 12 13 sEOVENTIAL OCCURHENCE REPORT REVISION EVENT YE AR REPOHT NO. CODE TYPE NO. LER

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27 10131 28 29 It i 30 L---J 31 LOJ 32 _ 21 22 2J KFr ACT t oN PL NT TET HOURS S8 IT D FOR lb B. S PLIE MAN FACTunER LA_j@[Z_j@ lZ l@ [Z j@ l 0 l0 l0 l0 l lY 41 l@ [y_j@ lAl@ lV 44 l0 l9 1547l@ 33 34 35 36 31 40 42 43 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h Iil0 l l The cause c,f this occurrence was a mechanical failure of the solenoid air sucolv i 11 15 I l valve (S0 2-1601-52A) to the operator of vent valve A0 2-1601-23. The solenoid l [il7j l valve was replaced and valve A0 2-1601-23 was cycled three times and proven to be l l3 ;3l l operable each time. l l 11141 l 80 7 8 9 STA s  % POWEH OTtlER STATUS IS O HY DISCOVERY DESCRIPTION . Operational Event l li 15 l lF l@ l0 l 7l 6l@l NA l lA l@l A TlVITY CO TENT RELE ASED OF RE LE ASE AMOUNT OF ACTIVITY LOC ATION OF RELE ASE NA l l NA l l1l6 7 8 9 l [_0] @ to- l Z l@l11 44 45 80 PERSONNEL e XPOSURES NU'/S E R TYPE DESCR. I t i l 71 1 0l O l 01@Lz_l@l NA

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ne,.tE or rarPAGER D. Hannum PHONE: 309-65h-??hl FvP_ 757 t,

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l. LER NUMBER: LER/R0 78-38/03L-0

11. LICENSEE NAME: Commonwealth Edison Company Quad-Cities Nuclear Power Station 111. FACILITY NAME: Unit Two IV. DOCKET NUMBER: 050-265 V. EVENT DESCRIPTION:

On November 25, 1978 while Unit Two was operating in the RUN mode at 2047 HWt, the Unit Two operator found that vent valve A0 1601-23 failed to open when the control switch was actuated. The vent valve could only be opened and closed by physically tapping the solenoid valve. The vent valve was left closed until the solenoid could be replaced. The downstream valves A0 2-1601-63 and A0 2-1601-24 were proven operable as required by Technical Specification 3.7.D.2. Work request 5382-78 was initiated to correct the problem. VI. PROBABLE CONSEQUENCES OF THE OCCURRENCE: Valve A0 2-1601-23 is riormally closed and is used to period-Ically vent the drywell. Alternate venting capability of bypass valve A0 2-1601-62 was availabic at the time of the occurrence. Since the valve remained in the closed position, no detrimental effect was made on overall plant safety. Vll. CAUSE: The apparent'cause of this occurrence has been determined to be a malfunction in the solenoid air supply valve 50 2-1601-52A to the operator of vent valve A0 2-1601-23 The solenoid valve Internals had become worn and dirty resulting in a mechanical failure of the solenoid valve. The solenoid valve is a Versa product model number VPS-4422. Vill. CORRECTIVE ACTION: The solenoid valve was replaced and the air throttle valve was adjusted. The A0 2-1601-23 valve was cycled three times and proven to be operable each time.}}