ML20084U175

AO 50-265/75-10:on 750326,during Surveillance Test,Pressure Suppression Valves AO-2-1601-23,56 & 63 Failed to Close in Required Time.Caused by Unadjusted Air bleed-off & Solonoid on Valve AO-2-1601-63 malfunction.Bleed-offs Adjusted

ML20084U175
Person / Time
Site:	Quad Cities
Issue date:	04/05/1975
From:	Kalivianakis N COMMONWEALTH EDISON CO.
To:	Oleary J Office of Nuclear Reactor Regulation
Shared Package
ML20084U176	List: ML20084U175 ML20084U178
References
AO-50-265-75-10, NJK-75-178, NUDOCS 8306270106
Download: ML20084U175 (3)

Text

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Aprli 5, 1975 Mr. John F. O' Leary, Di rector Directorate of Licensing Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20545

REFERENCE:

Quad-Cities Nuclear Power Station Docket No. 50-265, DPR-30 Appendix A, Sections 1.0.A.2, 6.6.B.I.a and Table 3.7.1

Dear Mr. O' Leary:

Enclosed please find Abnormal Occurrence Report No. 50-265/75-10 for Quad-Cities Nuclear Power Station. This occurrence was previously re-ported to Region 111, Directorate of Regulatory Operations by telephone on March 26, 1975 and to you and Region Ill, Directorate of Regulatory Operations by telecopy on March 26. 1975.

This report is submitted to you in accordance with the requirements of Technical Specification 6.6.B.l.a.

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

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N. J. Kalivianakis Station Superintendent NJK/lk cc: Region lil, Directorate of Regulatory Operations.

• J. S. Abel O h PDR 3973 con SENT REION

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REPORT NUMBER: A0-50-265/75-10 o

REPORT DATE: April 4, 1975 OCCURRENCE DATE: March 26, 1975 FACILITY:

Quad-Cities Nuclear Power Station Cordova, Illinois 61242 IDENTIFICATION OF OCCURRENCE:

Failure of pressure suppression valves A0-2-1601-23, A0-2-1601-56, and A0-2-1601-63 to close in the required time.

CONDITIONS PRIOR TO OCCURRENCE:

Unit 2 was shutdown in the refuel mode.

DESCRIPTION OF OCCURRENCE:

During operating cycle surveillance testina of the Unit 2 pressure sup-pression valves on March 26, 1975, the closure -times of the above valves were found to exceed their Technical Specification limits. A work re-quest was initiated to repair the subject valves.

DESIGNATION OF APPARENT CAUSE:

Equipment Failure The air bleed-off on all three valves were found to be out of adjustment.

Additionally, the solenoid on valve A0-2-1601-63 was malfunctioning.

ANALYSIS OF OCCURRENCE:

All valves involved are normally closed during reactor power operation.

Upon the receipt of a Group ll Isolation signal the valves are signaled to close. Based upon the fact that-the valves are normally closed and simply remain closed under an isolation signal there is minimal effect

-on reactor safety from slow closure time..

A0-2-1601-63 did operate in both. directions'on December 18, 1974 and in the open direction when the'drywell was.being purged on necember.20, 1974 at 10:20 p.m. prior to the Unit 2 shutdown on December 23, 1974.

The valve then remained open to sustain air circulation in the drywell throughout the subsequent refueling outage. The valve was. tested for

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j0-50-265/75-18 O ga" 2 .

. Tne safety imp 11-close.are m inimal since closure time on March 26, 1975 and failed to close valve to cations of the failure of A0-2-1601-63 The failure occurred while. j it was operable prior to the reactor shutdown. f l mode, 1 the unit was shutdown and depressurized in the re ue There were no personnel injuries or abnormal f radiation not exposures as a}(!

result of this occurrence and the public health and sa ety were affected. I D,

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CORRECTIVE ACTION: i h mal- )p The corrective action was to initiate a work request to repa functioning valves.

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d and was replaced and the bleed-of fs on all three valves j Upon the completion of the work on fiarch limit. 26, the valves were retes all closed within the 10 second Technical Specification FAILURE DATA: _

d with The failure data Indicates only two air operatedired time limit.

valves associate d during a i

the 1600 system previously would not close within the requ ,

Since Group ll these valves are also normally closed and remain c lative experience are again minimal.

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