05000010/LER-1977-041-03, /03L-0:on 771023,water Leaked to C Holdup Tank & Ground During Normal U-1 Radwaste Operation.Caused by Scratched Valve V3 & V45 Seats & Worn Manhead Gasket.Valve Seats Lapped,Manhead Gasket Replaced & Hatch Tightened

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/03L-0:on 771023,water Leaked to C Holdup Tank & Ground During Normal U-1 Radwaste Operation.Caused by Scratched Valve V3 & V45 Seats & Worn Manhead Gasket.Valve Seats Lapped,Manhead Gasket Replaced & Hatch Tightened
ML19338E407
Person / Time
Site: Dresden Constellation icon.png
Issue date: 11/23/1977
From: Mohr T
COMMONWEALTH EDISON CO.
To:
Shared Package
ML19338E406 List:
References
LER-77-041-03L, LER-77-41-3L, NUDOCS 8009290531
Download: ML19338E407 (3)


LER-1977-041, /03L-0:on 771023,water Leaked to C Holdup Tank & Ground During Normal U-1 Radwaste Operation.Caused by Scratched Valve V3 & V45 Seats & Worn Manhead Gasket.Valve Seats Lapped,Manhead Gasket Replaced & Hatch Tightened
Event date:
Report date:
0101977041R03 - NRC Website

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U.S. NUCLEAR REGULAT5GY COMMISSION (7 M )

iP c.lCENSEE EVENT REPORT-w "CONTi?OL BLOCK:

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8 60 61 DOCKET NUMBER 68 69 EVENT DATE 74

'S REPORT DATE So EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h iei2l l During normal operations of U-l Radwaste, U-l neutralizer was being pumped to B SSG l

,3,3; j waste collector. Valves V3 and V45 leaked 7000 gal of H20 to empty C heldup

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Worn gasket on a manhead allowed approx 12 gal of H20 contain-l t O lsi l ing 2.5 E-4 Ci to leak to ground. Some leakage was collected and returned to U-l l

10teIl neutralizer. No leakage reached uncontrolled areas. Leakage into controlled areas l

1017 l l vas cleaned. The event posed no threat to public safety.

Minor spills occurred]

ioisl l previously 50-010/70-1 and 50-010/77-1.

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CAUSE

CdfSE COMP.

VALVE code CODE SUBCODE COMPONENT CODE SUBCODE SUSCODE l0l9l l Ml Alh Wh (_Bjh I V l A l L l V l E l X lh l Cl@ l Dl @

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9 10 11 12 13 18 19 20 SE QUENTI AL OCCURRENCE REPORT REVISION LE R 'RO EVENT YE AR REPORT NO.

CODE TYPE No.

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33 i4 3h 36 32 40 41 42 43 44 47 CAUSECESCRIPTION AND CORRECTIVE ACTIONS h IllOl t h?ve seats in valves V3 and V45 were scratched, causing leakage to C holdup tank l

r i (1 l l above the lower manhead. The valves seats were lapped.

The manhead gasket was re-l

,,,,, l placed and the hatch tightenc.d.

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44 4s 46 so AMOUNTgF ACTIVITY @ l RELEASED OF RELE ASE LOC ATION OF RELE ASE 1f 16 1 [1_l h [_P,j @ l 2.5 x 10-Curies l

Ground adiacent to "C" holdun tank l

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ATTAfmMENT TO LICENSEE EVENT REPORT 77-041/03L-0 COMMONWEALTH EDISON COMPANY (CWE)

DRr.SDEN UNIT 1 (ILDRS-1)

DOCKET # 050-010 Unit 1 neutralizer was being pumped to B-SSG waste collector at 0035 on 10/23/77. At the same time B-SSG waste collector was being pumped to Unit 2/3 radwaste B-neutralizer. At 0250 the operator discovered water The leaking from the lower manhead of C-holdup tank onto the ground.

release area was posted and covered.

Samples were taken for isotopic Valve V-3 and V-45 had leaked because of scratched valve seats, analysis.

allowing approximately 7000 gallons of water to enter C - holdup tank.

The level was raised This was determined from the increase in tank level.

to six inches above the lower manhead. A worn gasket on th" manhead per-mitted water to leak to the ground. A bucket vss placed unour the leak and leakage rate was determined to be approximat.ely 1/8 gallon per minute.

Using the distance of the bottom of the manhead to the final fluid level and assuming the tank was filled at a " constant rate, it was determined that the tank had been leaking.for approximately 96 minutes.

Therefore, the water which was released amounted to approximately 12 gallons.

The activity of the water was found to be 5.5 pCi/L.

the total release amounted to 2.5 x 10-4 Ci.

The water in C - holdup

. Thus, tank was pumped to Unit 2/3 radwaste B-neutralizer. The water collected by bucket was returned to Unit 1 neutralizer. The release was contained in a controlled area and no water was released to the river.

The valve seats were repaired and the manhead gasket was replaced.

Safety significance of this event was minimal because of the small amount of the release.

Previous occurrences were reported under R.O. #50-010/1976-1 and 50-010/1S77-1.

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l' NRC DISTRIZUTION pen PART 50 DOCKET MATERIAL INCIDENT REPORT i

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FROM:

oATE OP coCUMENT Comonwealth Edison Company 11/23/77 Mr. James G. Keppler Morris, Illinois e4TE RECEivEm B. B. Step'tenson 12/09/77 i

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Licensee Event Report (R0 50-010/77-041/-031,

0) on 10/23/77 concerning valve seats in valves V3 & V45 being scratched, causing leakage to C holdup tank above the lower i

manhead.....

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l PLANT NAME: Dresden Unit No.1 l

RJL 12/09/77 (1-P)

(1-P)+(1-P)

NOTE: IF PERSONNEL EXPOSURE IS INVOLVED l

SEND DIRECTLY TO IGiEGER/J. COLLINS

/ WWh FOR ACTION /INFORMATION s

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