ML20084U159

AO 50-265/75-12:on 750417,check Valves 2-220-20B & 67B Failed to Check & 2-263-2-31H Leaked Excessively.Caused by Weak Springs & Pitted Poppets.New Springs & Poppets Installed

ML20084U159
Person / Time
Site:	Quad Cities
Issue date:	04/25/1975
From:	Kalivianakis N COMMONWEALTH EDISON CO.
To:	Oleary J Office of Nuclear Reactor Regulation
Shared Package
ML20084U160	List: ML20084U159 ML20084U162
References
AO-50-265-75-12, NJK-75-220, NUDOCS 8306270078
Download: ML20084U159 (2)

Text

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D$ Qu:d-Citics Merating Etation

• I Post O!Sce Box 216 h7 M Cordova. II:- ,61242 TcI:phonc(,1654 2241 7m 1 33 ^

fy'y 13 ^ ~

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,v - -i HJK-75-220 , , .. ' Q April 25, 1975 .

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q,s Mr. John F. O' Leary, Director -

Directorate of Licensing Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20545

Reference:

Quad-Cities Nuclear Power Station, Unit 2, Docket No. 50-265, DPR-30 Appendix A Sections 1.0.A.2, 3.7.D.1, 6.6.B.I.a

Dear Mr. O' Leary:

Enclosed please find Abnormal Occurrence Report No. 50-265/75-12 for Quad-Citics Nuclear Power Station. This occurrence was previously reported to Region lil, Directorate of Regulatory Operations in person on April 18,1975 anr: to you and Region li t , Directorate of Regulatory Operations by telecopy on Apri: 18, 1975 This report is submitted to you in accordance with the requirements of Technical SpectfIcation 6.6.B.l.a.

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

,4Y a. 'Y N. J. Kalivianakis a Station Superintendent NJ K/LDR/vmm i

Enclosure f cc: Region li t , Directorate of Regulatory Operations J. S. Abel

$O y,y .[w v 1

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/ l 8306270078 750425 PDR ADOCK 05000265 PDR  ?, j Jg5j S

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,REPCRT-NUMBER: A0 50-265/75-12 [

REFORT DATE: April 27, 1975 ,S OCCURRENCE DATE: April 17, 1975

'N FACILITY: Quad-Cities Nuclear Power Station Cordova, Illinois 61242 J

4 IDENTIFICATION OF OCCURRENCE:

"}

Flow Instrument check valve failures ,

CONDITIONS PRIOR TO OCCURRENCE: -

1 o

Unit Two in cold shut down condition. Reactor hydrostatic ' pressure test being performed. .3 L

DESCRIPTICN OF OCCURRENCE:

On April 17, 1975 at 1700, while performing a reactor hydrostatic pressure test, two check valves, 2-220-20B and 2-220-678, failed to check; and check valve 1-263-2-31H

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leaked excessively thereby exceeding Technical Specification 3 7.D.I. The hydro test was terminated and work request 1374-75 issued for repair of these check valves. 1 DESIGNATION OF APPARENT CAUSE OF OCCURRENCE:

i-Equipment Failure - Cause of the valves to fall was determined to be weak springs and pitted poppets on all three valves. The 2-220-20B valve seat needed lapping.

ANALYSIS OF OCCURRENCE:

Safety implications are minimal. The purpose of these valves is to check the flow of water through the small instrument 1inc in case the instrument 1Inc severed. m There Is also a manual isolation valve located on the instrument line. Had the [

instrument line severed during operation of the plant, reactor water and steam would 3 have been contained in the reactor building along with fission product gases. The reactor water and condensed steam would have been collected in the reactor building floor drain sumps and the fission gases controlled by the reactor building venti-lation system or, if needed, the stand-by gas treatment system. The flow of coolant ,

and gases would have been isolated by the manual valve within a short period of time, i g Had tnis occurred, the entire event would have been completely controllable with no j consequences to the health and safety of the public or plant personnel. Because the check valves were found faulty and repairs made during pre-start-up testing,  ?

consequences to health and safety were non existant.

L

_ CORRECTIVE ACTION:

All check valves-had new springs and poppets installed and the 2-220-20B valve seat [

was lapped. Repairs were completed on April 23, 1975. Proper valve operation was , ,

then verified at normal reactor operating pressure.

FAILURE DATA:

instrument line check valve failures have happened previously at quad-Cities Station (See A0-50-524/74-21). However, this is.the first time-such an event was caused by L faulty component parts.

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