ML20084S318

AO 50-265/75-25:on 750721,two Hydraulic Snubbers Found to Have Empty Oil Reservoirs.Caused by Several Oil Leaks for One Snubber.Failure of Second Snubber Unknown.One Snubber Fitting Tightened & Other Snubber Replaced

ML20084S318
Person / Time
Site:	Quad Cities
Issue date:	07/31/1975
From:	Kalivianakis N COMMONWEALTH EDISON CO.
To:	Office of Nuclear Reactor Regulation
Shared Package
ML20084S320	List: ML20084S318 ML20084S326
References
AO-50-265-75-25, NJK-75-390, NUDOCS 8306160654
Download: ML20084S318 (3)

Text

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"s bp [h Commonwe:lth Edison

) Quad-City' 'juclear Power Station

', Po::t Ofrect.;x 216 ' .

• • Cordova, Illinois 61242 2,-(i'i_

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, Telephone 309/654-2241 . .;

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July 31, 1975 O~ ** *; * ;

Director- of Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington D. C. 20555

Reference:

Quad-Cities Nuclear Power Station l Docket No. 50-265, DPR-30, Unit 2 1 Appendix A, Sections 1.0.A.2, 3.6.1.1, 6.6.B.I.a ';

Enclosed please find Abnormal Occurrence Report No. A0 50-265/75-25 for quad-Ci ties Nuclear Power Station. This occurrence was previously reported to Region Ill, Directorate of Regulatory Operations by telephone on July 22, 1975 and to you and Region Ill, Directorate of Regulatory Operations by telecopy on July 22, 1975 This report is submitted to you in accordance with the requirements of Technical Specification 6.6.B.I.a.

Very truly yours, COMMONWEALTH EDISON COMPANY QUAD-CITIES NUCLEAR POWER STATION

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N. J. Ka1iv'lanokIs Station Superintendent j NJK/TJ/lk i cc: Region lil, Directorate of Regulatory Operations J. S. Abel l

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'R'EPORT WUMBER: A0-50-265/75-25 o: o u Ll 1

RE' PORT DATE: July 31, 1975 f OCCURRENCE DATE: ' July 21, 1975 FACILITY: Quad Cities Nuclear Power Station Cordova, Illinois 61242 ,

'l0ENTIFICATION OF-0CCURRENCE:

Ona- (1) Grinnell, and one (1) Bergen-Patterson hydraulic snubber were found to heve empty

. oil reservoirs.  ;

CONDITIONS PRIOR TO OCCURRENCE:

Unit 2 was'in the cold shutdown mode for maintenance. ,

DESCRIPTION OF OCCURRENCE:

During the surveillance of hydraulic snubbers on Unit 2 during a maintenance outage, Grinnell.

snubber number. 4750, on the pump suction line for the reactor water clean up system, was found to have.an empty oil reservoir. A work request (number 2671-75) was written to have i the snubber repaired. '

I A Bargen-Patterson snubber (number 132) located inside the drywell at 90 .on the recirc ring hradar, was also found to have an empty reservoir.

' DESIGNATION OF APPARENT CAUSE OF OCCURRENCE: l 1

. Equipment Failure - l The apparent cause of this occurrence is designated as equipment failure. The Grinnell f Snubber ^had several oil leaks that allowed the reservoir to become drained. The Bergen-Patterson-snubber was replaced and will. be disassembled in the future for repairs; .the exact cause of .i its failure ls thus not known.

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j. . ANALYSIS OF OCCURRENCE: -

Snubbers' arc designed to prevent unrestrained pipe motion under dynamic loads as might occur during 'an earthquake or severe transient. Since snubbers are only required during low pro-bability events, a period of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is allowed for repairs or replacement while the plant is cperating.

_W hsn the snubbers were. found defective they were replaced and no damage .to the --lines to which

! thay were attached had occurred. 'Since there was no line failure or release of radioactivity-in the plant or to the environs there' was no effect on the health or safety of the public.

!- CORRECTIVE ACTION:

, -Tha Grinnell snubber was repaired.by tightening the fittings.that. allowed the oil to leak; ~

L ~from the reservoir. ~ 'The Bergen-Patterson snubber was replaced with a rebuilt' snubber (number.

165) of, the '_same type. The removed snubber will be disassembled and rebuilt in' the future.

. Station Work Requests. Number 2671-75 an'd 2707-75 document the work' performed to repair the.

foiled ~ snubbers..

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I FAILURE DATA: }

> The same Grinnell snubber was found to have an empty oil reservoir on December 30, 1974.

A leaky fitting on the line from the reservoir was tightened, the reservoir refilled, and no leakage was observed.

Tha Bergen-Patterson snutsber liad been rebuilt and replaced during the spring 1975 reftcaling

- outage. This was the first inspection of this snubber since the outage.

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