ML19320B560

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First Interim Deficiency Rept Re Selector Switches Environ Qualification.During Review of Switch Contract Documents, Documentation Not on File to Substantiate That Switches Are Environmentally Qualified to Withstand Temp
ML19320B560
Person / Time
Site: Sequoyah Tennessee Valley Authority icon.png
Issue date: 07/07/1980
From:
TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML19320B551 List:
References
NCR-SQN-EEB8008, NUDOCS 8007140456
Download: ML19320B560 (1)


Text

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v p ENCLOSURE SEQUOYAH NUCLEAR PLANT UNIT 2 SELECTOR SWITCHL; ENVIRONMENTAL QUALIFICATION NCR SQN EEB 8008 10 CFR 50.55(e)

FIRST INTERIM REPORT Description of Deficiency Cutler-Hammer switches type 10250T are used in Class IE control-circuits for safety related equipment. The switches are

- mounted locally to the equipment and ar- tsed in testing such that equipment operability can be dire < f observed. The switches are wired in the circuits with other sw cches in the main control room which are used to control the equipment manually or automatically.

During a review of the switch contract documents, it was found that documentation is not on file to substantiate that these switches are environmentally qualified to withstand the temperatures which could result from certain high energy line breaks.

Switches-are located in local control boxes at each of the following locations:

(number of switches per unit is in parentheses)

1. Vertical Pipe Chase at elevations 653, 690, 699 and 714 (19) 2.- Auxiliary Feedwater Pump Turbine Room at elevation 669 (9)
3. RHR Heat Excha7ger Rooms at elevation 690 (2, one per room)
4. RRR Pump Rooms at- elevation 653 (6, three per room) l Interim Progress l

Twopossible.correctiveactionbarebeingevaluated. .One is to perform an environmental qualification test on a mounted switch j

and its related circuitry. The other is to' delete the switches j

from the equipment circuitry, using main control room switches i and 'a communications 'line to an observer near the components for testing.

l

'800714035(,

1