ML20084T033

RO 50-249/75-18:on 750324,during Surveillance Testing,Core Spray Valve 3-1402-4A Failed to Close Electrically.Caused by Fault in Motor Operator.Valve Closed Manually

ML20084T033
Person / Time
Site:	Dresden
Issue date:	04/04/1975
From:	Stephenson B COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
230-75, RO-50-249-75-18, NUDOCS 8306200426
Download: ML20084T033 (2)

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&' V'/ Address Reply to: Post O! hee Box 767 Chicago, Ilhnois 60690 EES Ltr. #230-75 Dresden Nuclear Power Station R. R. #1 Morris, Illinois 60450 April 4, 1975 Mr. James G. Keppler, Regional Director Directorate of Regulatory Operationc-Region III U. S. Nuclear Regulatory Co=r.ission 799 Roosevelt Road Glen Ellyn, Illino'is 60137

SUBJECT:

REPCRT OF UNUSUAL EVEC PER SH' TION 6.6.C OF THE TECHNICAL SPECIFICATIONS CORE SFRAY VALVE P.0-3-1402-4A

References:

1. Regulatory Guide 1.16 Rev. 1 Appendix A

2. Notificati5n of Region III of U. S. Nuclear Regulatory Co::enission Telephone: Mr. P. Johnson at 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> on March 24, 1975 Report Number: 50-249/1975-18 Report Date: April 4, 1975 Occurrence Date:  !" arch 24, 1975 Facility: Dreeden Nuclear Power Station, Morris, Illinois-IDC;TIFICATION OF OOCU RFTCE Core Spray Valve 3-1402-4A failure to close.

CC'!DITIO?!S PRIOR TO OCCURRE;CE Prior to the failure of core spray valvo 3-1402-4A to close the unit was in the "run" mode with thermal power at 1265 megawatts. The unit had an electrical load of 408 megawatts, and the core spray reonthly surveillance testing was in progress.

DESCRIPPION OF OCCURRFNCE On March 24, 1975 at about 0230 hours0.00266 days <br />0.0639 hours <br />3.80291e-4 weeks <br />8.7515e-5 months <br /> on core spray valve > 1402-4A failed to close electrically during surveillance testing. From previous failures it has been detemined that the 3-1402-4A valve cannot be closed electrically while a core spray pump is running. As corrective measures for, previous failures a unit operator was stationed at the valve prior to its operation to manually close the valve when necessary.

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7 I NI.,JamesG.Kepple April 4, 1975  ;

l DESIGNATION OF APPARET CAUSE OF OCCURRENCE k

!l From previous failures it has been determined that the 3-1402 4A valve draws a higher than rated current during its operation. The higher current draw

1. could be due to an internal valve problcm or an internal motor problem.

' It is presently believed that the cause of the' problem is due to a fault b in the motor operator. However, prior to changing the motor operator the valve will be disassembled and inspected during the next unit outage which is presently scheduled for the end of April. The results of the valve  ;

inspection will determine the cause of the failure more accurately. Following  ;

' the valve inspection a followup letter will be sent to Region III outlining additional corrective actions. Also, since no additional corrcetive actions will be made until after the valve inspection any additional failures of the .

valves during surveillance testing will not be reported to Region III except by telephone.

ANALYSIS OF OCCURRENCE

! The failure of the core spray valve 3-1402-4A to close electrically did not place the safety of the plant or public in jeopardy. The 3-1402-4A valve is used for test purposes only and is not required for system operability.

CORRECTIVE ACTIONS The im ediate corrective action taken was to close the valve manually. A unit operator has been stationed at the 3-1402-4A valve to manually close the

valve when necccsary. Additional corrective actions will be made following an inspecticn of the 3-1402-4A valve during the next refueling outage.

T'AILURE DATA The 3-1402-4A valve has failed to close electrically while a core spray pu p was running since Decenter 1974. All previous failures occurred while perfc= ins monthly surveillance testing. ,,'

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.B. .B Sttshenson Superintendent BBS:TEL smp File /KRO

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