ML20084D427

Ao:On 750520,electromagnetic Relief Valve 2-203-3C Failed to Open During Scheduled Surveillance.Caused by Adjustment Problem in Pilot Valve Linkage.Capscrew Out of Adjustment. All Electromagnetic Relief Valves Adjusted

ML20084D427
Person / Time
Site:	Dresden
Issue date:	05/30/1975
From:	Stephenson B COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
335-75, 6045, AO-50-237-75-30, NUDOCS 8304110186
Download: ML20084D427 (2)

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Addrest w/fy to: Poct Omce Box 767 Chicago, libriois 60090 BBS Ltr. #335-75 Drceden Nuclear Power Station R. R. #1 4

Morris, Illinois 60450 g-l May 30, 1975 p/ M. D l\\

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1/c. James G. Koppler, Regional Director

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REFORT OF AI"!OPPAL OCCURRFNCE PER SECTION 6.6.A 0F 'Q

SUBJECT:

SPEIFICATIC:!S ETJETRO:.'.T1c RELIEP VAINE PAILED TO OPEN

References:

1) Regulatory Guide 1.16 Rev. 1 Appendix A

2) Notification of Region III of U. S. Nuclear Regula%ry Cornission Telephone P. Johncon, 0930 hours0.0108 days <br />0.258 hours <br />0.00154 weeks <br />3.53865e-4 months <br /> on May 20, 1975 Telegram:

J. Keppler, 1515 hours0.0175 days <br />0.421 hours <br />0.0025 weeks <br />5.764575e-4 months <br /> on May 20, 1975

3) Drawing the.ber M12 Report Numbers 50-237/1975-30 Report Date: Ihy 30, 1975 s

Occurrence Datos May 20, 1975 Facility: Dresden Nuclear Power Station, Morris, Illinois IDWTIFICATION OF OCCURRD?CE The 2-203-3C electromatic relief valve failed to open during a scheduled. survoillance.

This represents a condition which could prevent a cafety system component from

. performing its intended safety function.

i CONDITIO:!S PRIOR TO OCCURRD!CE Unit-2 was in the run modo during a routine startup operation when the incident occurred. The unit was at 405 LTt and zero electrical load.

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At approximately 0400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br /> on May 20, 1975 the 2-203-3c electromatic relief valve failed to open when actuated manually from the control room. The indicating lights shouad evidence of pilot solenoid operation but no reduction of bypass valve position or increace in discharge te:rporature was observed.

DESIGNATION OF APPARF2;T CAUSE OF OCCURRE:CE (Component Failuro)

The 2-203-3C electromatic relief valve failed to open because of an adjustment probica in the pilot valve linkage. The capscrew on the pilot operating lover that contacts the pilot valve ntem was found to be out of adjustment. Upon installation of the relief valve after r:aintenance, the contractor failed to make final adjustcents on the operating lever.

MIALYSIS OF OCCURRD!CE t

Reactor operation is permitted with one electrcmatic relief valve out of service.

The other unit,-2 relief valves vere tested ilmediately following the occurrence.

The HPCI system was also determined to be operable as required by Section 4.5.D.2 of the Technical Specifications.

CORRECTIVE ACTION All four electromatic relief valven were checked and adjusted to the proper tolerances. Surveillence tests rero then conducted on the relief valves and 30 operated catisfactorily; houever, 3B failed to open (this incident will be dio-cussed in subsequent report number 50-237/1975-32).

To ensure that thic problem does not recur, a check on the adjust:nont of the operating levers will be dono following all maintenance on the relief valves.

FAILURE DATA A similar incident occurred and was reported (50-237/1970-22) on the unit-2 3D clectromatic relief valve in 1970. These relief valves are P.odel Number 1525-VI.

electromatic relief valves manufactured by Drecscr Industrial Valve.

n Sincerely, 1[fX.. '/

0Y AJ "B.*B.Stlephencon Superintendent BSS:JEM:a=p FileAIRC

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