ML20141N150

Procedure Fcr 85-227, Main Feedwater Block Valve Interlock

ML20141N150
Person / Time
Site:	Davis Besse
Issue date:	02/26/1986
From:	TOLEDO EDISON CO.
To:
Shared Package
ML20141N145	List: ML20141N144 ML20141N147 ML20141N150 ML20141N153 ML20141N156 ML20141N160 ML20141N163 ML20141N168 ML20141N172 ML20141N176 ML20141N179 ML20141N180
References
FCR-85-227, TAC-61015, NUDOCS 8603040419
Download: ML20141N150 (1)

Text

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M2W ELOCK VALVE INTERIDCK FCR 85-227 I. PURPOSE A. Reduce plant transients and trips caused by failure related to these interlocks II. DESCRIPTION A. Remove the interlock between main feedwater valve position and ICS feedwater flow selection

1. Make ICS always read main feedwater flow B. Remove the interlock between the main feedwater block valves (FW779 and FW780), and startup feedwater valve position

1. Install a signal to close the main feedwater block valves on a reactor trip C. Block Valve Control I

1. In the open position the block valves will still open and stay open

2. In the close position the block valves will still close and stay closed

3. In the auto position the ICS will close the block valves only if the Reactor trips

a. All other automatic closure or opening of the block valves by ICS is removed III.

SUMMARY

A. This change affects the ICS interlocks associated with i

the Main Feedwater Block valve

1. Since the modified circuit cannot switch between S/U and Main FW flow measurements, failures involving undesirable transfer between the two (2) measurements are eliminated

2. Since the strip chart recorder will only display Main FW flow rate, potential uncertainty concerning which measurement is displayed is eliminated 4

3. This change eliminates the interlock between S/U valve position and the Main FW block valves, thus rsquiring the operators to manually control the valves 8603040419 860226 PDR V ADOCK 05000346 PDR

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