ML20150E159

/03L-0 on 781027:5 Snubbers Which Had Empty Reserviors Were Proven Inoperable When Bench Tested.Caused by Hydraulic Fluid Leakage.Leakeage Sources:Reservoir Seals, Leaking Body Joints & Adjustment Screw Thread Seals

ML20150E159
Person / Time
Site:	Zion File:ZionSolutions icon.png
Issue date:	11/22/1978
From:	Richardson C COMMONWEALTH EDISON CO.
To:
Shared Package
ML20150E149	List: ML20150E146 ML20150E159
References
LER-78-120-03L, LER-78-120-3L, NUDOCS 7812110164
Download: ML20150E159 (3)

Text

WitC F OllM 366 U. S. NUCLE AR llLG UL A l OllY COMMISSIOrd (7 77)

LICENSEE EVENT REPORT i cONTnOL DLOCK: l l l l l lQ (PLEASE PRINT On VYPE ALL REQUIRED INFORMATION) i~g l Il L l 7 l Il S 11 l@l0 l 0 l -l 0 l0 l 0 l 0 l 0 l - l0 l 0 l@l 4l 1 l 1l 1 l 1l@l l l@

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M 14 7b 7 0 00 01 DOLKE r NUr/ut h 6') EVENT OATE HLPOHT DAIL HQ EVENT DISCHIPTION AND PROBABLE CONSEQUENCES h

_ [ol2l l Durino refuelino surveillance, 5 snubbers ( 3 accessible & 2 inaccessible),

_ [o l3 l l which had enpty reservoirs were nroven inonerable when bench tested. 1

. I O 141 l railures did not render their associated systens inoperable. These l 7;ogs;jsnubbers are desianed for seismic event protection. Since this low l

, lO le ] l probability event did not occur, public health & safety were not affected) 10 l 7 l l Previoun events (50-295/77-0, 55, 64, 69, 70, 80, 92 and 50-304/78-34). l 10181I 60 l

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SYST E M CAUSE CAUSE COMP. VALVE CODE CODE SUBCODE COMPONENT CODE SUCCODE SUBCODE

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_jnl0l 0i0l40 ly jg l y lg 'in l@ II l 2 l Oj 7 lg 44 J/ di 42 43 47 cAUSE DESCRIPTION AND CORRECTIVE ACTIONS h l1l0ll Hydraulic fluid leaked out of snubbers. Leahane snurces were reservoirI g lscals, leaking body icints, and adiustment screw thread seals. Snubbers !

,,;73lwith leakinc body was replaced, reservoir seals were tichtened and threa<!!

,,.,jl seals replaced by ethylene propylene. The snubber- were fiJled & 4. n ,. ra l I i 14 I I Peri ec i c insnectinnn i a n n +- i #" nrnbin- nnnhhnre.

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ATTACHMENT TO LFR NO. 78 - 120/ 0? L-O COMMO!MEALTH EDISOti CO.

ZION GENERATING STATION 50-295 Description of Event The following accessible snubbers were found inoperable during the refueling snubber surveillance:

P Snubber f Line #

MSRS 115 1MS003-35b" Main Steam Line from S/G 1D SIRS 1251 1SI001-8" Containment Sump Recirc thru containment Spray BDRS 1037 1BD006-2" Blowdown Line The following inaccessibic snubbers were found inoperable during the refueling snubber surveillance:

Snubber # Line #

RCRS 1009 1RC140-14" Pressurizer Surce Line SIRS 1309 ISI 034-10" Accumulator Discharge Line These five snubbers had empty reservoirs. They were rer e 'd and bench tested. The snubbers failed to lockup during the c. .

Consequences of Event These snubber failures did not render their respective systems inoperable. These snubbers are designed for seismic and severe transient protection. Since neither of these low probability events did not occur, public health and safety were not affected. Snubbers have been found inoperable in the past. These are detailed in reports: 50-295/77-8, 55, 64, 69, 70, 80, 92 and 50-304/78-34.

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8 1 Cause of Occurronce and Corrective Action The cause of these failures was fluid leakage.

Snubber 8 Leakane Sources Corrective Action RCRS 1009 Dody of Snubber Snubber Replaced BDRS 1037 Reservoir Seals Seals were tightened and SIRS 1251 Reservoir Seals adjustment screw thread seals replaced as precaution.

SIRS 1309 Adjustnent Screw Seals Seals were replaced t1S RS 115 Adjustment Screw Seals Seals were replaced The newly installed seals were ethylene propylene type. The snubbers were refilled and retested satisfactorily before reinstallation.

Periodic inspections identify problem snubbers. No further corrective action is deemed necessary.

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