ML19031B355

Response to Request for Additional Information Regarding Auxiliary Building Flooding

ML19031B355
Person / Time
Site:	Salem
Issue date:	07/23/1975
From:	Mittl R Public Service Electric & Gas Co
To:	Anthony Giambusso US Atomic Energy Commission (AEC)
References
Download: ML19031B355 (3)

Text

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Public Service Electric and Gas Company 80 Park Place Newark, N.J. 07101 Phone 201/622-7000 July 23, 1975 Mr. A. Giambusso Director, Division of Reactor Licensing U~ So Nuclear Regulatory Commission Washington, D. c.

20555

Dear Mr. Giambusso:

AUXILIARY BUILDING FLOOD PROTECTION NOo 1 AND 2 UNITS SALEM NUCLEAR GENERATING STATION DOCKET NOS. 50-272 AND 50-311

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itt. uLi ~,. u Our letter of December 19, 1974 to the Director of Regulatory Operations reported t.he failure of Nao 1 Unit 4 kV vital switchgear due to flooding from a severe northeast storm on December 1, 1974.

A telephone request for additional information was made by Mro Ao W. Dromerick of your staffo The attached response to. Mr. Dromerick's request is hereby transmitted for your reviewo Very truly yours, R., L. Mittl General Manager - Projects Engineering and Construction Department The Energy People 810 U 9&-2001. 250M R* 74 1

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QUESTION 1 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION AUXILIARY BUILDING FLOODING NO. 1 AND 2 UNITS SALEM NUCLEAR GENERATING STATION Are there any water lines in the electrical switchgear rooms?

If so, please provide drawings.

ANSWER A 12-inch Class I (Seismic) demineralized water line passes through the switchgear room at elevation 64'.

This line is a non-essential bac~-up water supply to the Auxiliary Feedwater System and will remain dry during normal plant operation, there-by precluding any. potential for accidental water. intrusion into vital electrical plant areas.

QUESTION 2 Would a crack in a moderate energy, Class I (Seismic) pipe anywhere in the Auxiliary Building prevent the safe shutdown of the unit?

ANSWER We have investigated the effects of a "critical crack" in the moderate energy, Class I (seismic) piping in the Auxiliary Building.

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~j The investigation indicated that a "critical crack" (taken to be 1/2 the pipe diameter r~

in length and 1/2 the wall thickness in width) in any of these lines would not inter-H fere with the safe shutdown of the unit.

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Equipment arrangement and floor drainage systems are adequate to prevent flooding serious enough to impair the o-peration of equipment necessary for shutdown.

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the event of any Class I (Seismic) line failure of "critical crack" size, the discharge1 effluent would be carried away via existing floor drains or via stairwells and pipe.

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RHR sump level alarms would alert the operator to take the necessary action required I

to maintain the plant in a safe condition.

To.minimize discharged effluent from yard

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tanks into the Auxiliary Building, given a "critical crack" in a Class I (Seismic)

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pipe, steps could be taken in the yard area to reduce tank inventories or divert the inventory to other storage facilities.

• QUE§~ION 3 Will all floor penetrations be sealed?

ANSWER It is planned to seal the floor penetrations between elevations 100' and 84', and 84' and 64' in the switchgear roomso QUESTION 4

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What type fire protection is provided in the switchgear rooms?

Is it water del:uge?

ANSWER co2 fire protection is provided in the switchgear rooms.