ML19225C816

Final Deficiency Rept Re Essential Raw Cooling Water Valve Positioning.Automatic Opening Signals to Essential Raw Cooling Water Valve Will Be Removed Before Initial Criticality of Unit 1

ML19225C816
Person / Time
Site:	Sequoyah
Issue date:	07/03/1979
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML19225C813	List: ML19225C812 ML19225C816
References
NCR-MEB-79-22, NUDOCS 7908020485
Download: ML19225C816 (1)

Text

=4 < r ENCLOSURE -

SEQUOYA1; NUCLEAR PLANT UNITS 1 AND 2 -

ERCW VALVE POSITIONING NCR MEB 79-22 l.'

FINAL REPORT 10 CFR 50.55 (e) ..

Description of Deficiercy On a safety injection signal the valves on the discharge side of the component cooling system (CCS) heat exchanger C are automatically energized to the full open position. These valves (PCV-67-151 header A, FCV (ERCW) 152 header B) control the flow of essential raw cooling waterThe ERCW System is designed exchanger.

through the tube side of the heat exchanger with so that the necessary flow is provided through the heat only one valve open.

loss of offsite power and a failure of

'In the event of a concurrent power train A the open!ng of both valves would cause excess ERCV train B flow through heat exchanger C. This would result in insufficient flow in the rest of ERCW train B.

Safety Implication Statement The reduction of the required flow through the ERCW train B components exchanger C in the event in ofinadequate a loss of offsite cooling other than the CCS heat power and a failure of power train A would resultThis lack of cooling would adversely of required safety-related equipment.to achieve safe shutdown.

affect the ability of the plant

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Corrective Action All automatic opening signals to the ERCW header A1. valve (FCV-67-151) will be removed bef ore initial criticality of Unit iA37 288 70 0802 o/ fgrg;~

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