ML20084U825

Ro:On 700409,16-inch Valve 2/3-3327-500 at 2/3A Condensate Storage Tank Found Improperly Closed.Caused by Lack of Instructions to Close Valve on 700403.Addl Requirements Initiated

ML20084U825
Person / Time
Site:	Dresden
Issue date:	04/17/1970
From:	Hoyt H COMMONWEALTH EDISON CO.
To:	Morris P US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084U829	List: ML20084U825
References
01286, 1286, NUDOCS 8306290294
Download: ML20084U825 (2)

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Dr. Pcter A. Morris, Director ,

Division of Ikac tor Licensing U. S. Atomic Energy Commission Washington, D. C. 20545 SUILTECT: License DPR-19, Dresden Nuclear Power Station Unit 2, Section 6.6B of Technien1 Specifications Daar Dr. Morris:

This is to report a condition relating to the, operation of the station in which the 16" valve 2/3-3327-500 at the 2/3A condensate storage tank was found to be improperly closed. The closed position of this valve prevented the #2-11FCI pump from obtaining its ncrmal initial supply of water from the tank during'a test'6peration and could have prevented the HPCI system fron performing as described in the SAR, although the normal

' torus uater supply was available as a backup supply. The situation was discovered on the 4 P.M. - 12 P.!! shif t on April 9, 1970, during a test run of the HPCI uith the reactor at 1000 psig and in the "RUN" mode. The valve was opened immediately and the IIPCI test run was conducted. All other-emergency c. ore cooling systems were operabic at the time. Thc 3 CI system was required to be operabic at the timcTapecified in Technical Specification 3.5.C.

1 The proper positioning of the valve was established during the conduct of the Unit 2/3 separation check list on February 7,1970. A

, review of subsequent operations leads to the conclusion that the valve l

was improperly positioned on April 3, 1970.

Conditions Icading to this situation were as fo11cws:

At 7:55 P.M. on March 29, 1970, a condenser tube leak developed requiring Unit 2 to be shut down. The resulting in-leakage of river water to the hotwell required rejecting and flushing the water in the hotwell, and subsequent replacement of storage water with high purity condensate.

Because of the large volume of water to be rejected (about 350,000 gallons) ,

a a ecial procedure was written and approved on March 31, 1970, and reject g'

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Dr. Peter A. Morris ~. 1 %< '

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• started at 1 30 A.M. on April 1, 1970. 6 ilid 970, a special pro-cedure was written and approved to transfer water from condensato storage tank 2/33 to 2/3A and to the hotwell. The procedure included the valving required to return the system to normal and required that the subject valve be open for the required transfer. The transfer was successfully completed, proving that the volve was open at this time. The procedure did requir e other valves to be closed in order to restore the system to normal, but did not require Valve 2/3-3327-500 to be closed. All valves were rechecked to be in the proper position on April 10, 1970, proving that no other valve was mistakenly identified as 2/3-J327-500 and that all valving was correct on April 9, 1970, except 2/3-3327-500 at t.he time it was found to be closed.

A review of the shift supervisors involved in the valving re-venled no instructions were issued to close the subject valve on 4/3/70.

The Unit 2/3 separation check list requires this valve to be open, whereas the normal position required for Unit 3 startup will require this valve to be cJoced as indicated on the piping dia,r: rams submitted by the consulting design engineering firm of Sargent and Lundy. It can only be assuued that an operator may have considered that this valve should have been closed and acting on his own initiative, closed the valve.

3 To correct the condition 1cading to improper operating valve lineup, additlonr.1 requirements have been initinted thich rc.;uire that the special operating procedure steps be dcted, initialed, and approved as complete by the shift supervisor and returned to the operating engineer for revicu and file. In addition, a rerun of the check list for the system involved will be required on all safety related systems as a doubic check on the proper completion of the special procedure and proper return of the system to normal.

Very truly yours,

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!!. K. Hoyt Superintendent liK11: day

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