ML20084B712

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Ao:On 720524,essential Svc Motor Generator Set Failed Resulting in Feedwater Control Sys Failure & Reactor Scram. Caused by Dirty Contacts on 2K Relay.Hfa Relay Replaced
ML20084B712
Person / Time
Site: Dresden, Quad Cities, 05000000
Issue date: 06/26/1972
From: Palmer E
COMMONWEALTH EDISON CO.
To: Bloch E
US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084B716 List:
References
FAP-72-120, NUDOCS 8304070043
Download: ML20084B712 (1)


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June 26,1972

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o co Mr. E. J. Bloch Acting Director, Directorate of Licensing U. S. Atomic Energy Commission Washington, D.

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20545 Refe rence :

License DPR-30,-Quad-Cities Nuclear Power Station, Unit 2

Dear Mr. Bloch:

The purpose of this letter is to clarify an incident which occurred on Unit 2 at Quad-Cities Nuclear Power Station on May 24, 1972.

This incident was reported to you by telegram on that date.

The incident was incorrectly reported to you as an abnormal occurrence as defined by Section 1. A.4 of the Te chnical Specifications.

The incident involved a failure of the essential service motor generator set which resulted in a feedwater control system failure and a reactor scram.

A review of the incident was conducted and it has been established Jhat this failure did not render any safety system incapable of performing its intended safety function as defined 'in the Technical Specifications.

The cause of the incident was traced to dirty contacts on the 2K relay in the MG set control circuit which pre-vented a transfer to, the backup DC supply.

This HFA relay has been replaced'with a 120H type relay with gold flash contacts to prevent a~ repetition of this occurrence.

Very truly yours, COMMONWEALTH EDISON COMPANY Quad-Cities Nuclear Power Station

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.x 8304070043 720626 gDRADOCK 05000265 F.

A. Palmer PDR Station Superintendent FAP/zm

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