ML20082H627

Special Rept 91-004:on 910806,water Level in Both Fire Protection Water Storage Tanks Observed to Be Below Ts. Procedure Changes Made to Verify Pressure Alarm Switches Are Properly Aligned & to Check Clapper Valve Supply Pressures

ML20082H627
Person / Time
Site:	Farley
Issue date:	08/19/1991
From:	Woodard J ALABAMA POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
91-004, 91-4, NUDOCS 9108260187
Download: ML20082H627 (2)

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August 19, 1991 Docket Hos. 50-348 50-364 U. S. Nuclear Regulatory Commission A11N: Document Control Desk Washington, DC 20555 Joseph M. f arley Nuclear Plant Special Report 91-004 The Volume Of Water in Both fire Protection Water Storage Tanks Was less Than 1he Technical Specifica11pjLLimit Gentlemen:

In accordance with the requirements of Technical Specification 3.7.11.1, '

the enclosed Special Report No.91-004 is submitted.

Respectfully submitted, pxJ. . Woodard 5 JDW/BHW: map 0819 Enclosure -

cc: Mr. S. D. Ebneter Mr. S. T. Hoffman Mr. G f. Maxwell 9108260187 910819 PDR S

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Joseph H. farley Nuclear plant Special Report No.91-004 The Volume Of Water in Both fire Protection Water Storage Tanks Was less lhan 1ho Technical Specification Limit j At 2130 on 8-6-91, the water level in both fire protection water storage tanks was observed to be below the level required to meet lechnical Saccification 3.7.11.1. Control room personnel became aware of a problem w1en the fire protection tank low level alarm came in at 2040. The Mw level alarm comes in when the water level in one of the tanks reaches 28 feet - 10 inches. Control room operators reviewed the plant computer for indications of fire system actuation, and no indications were noted.

Personnel were dispatched to look for possible leakage. The number 2 l clapper on Unit 2 cooling tower C was found to be tripped. The clapper was isolated, and the tank levels were increased above the minimum value by 2210.

The clapper valve tripped due to low pressure in a nitrogen bottle which was being used to hold the clapper valve closed. The nitrogen bottle was  ;

being used becaine the air compressor that normally su) plies air to the '

valve was inopet .ble. The minimum observed level in tie fire protection tanks was 25 feet, while the required minimum level is 26 feet. There was no effect on the fire protection capability for any safety-related equipment.

Control room ../sonr, , were not alerted of the fire suppression system activation because the pressure alarm switch associated with the tripped clapper valve was isolated. The alarm switch was apparently isolated when the clap:)er tripped on 07-15-91 and was not unisolated when the clapper was reset. )rocedures did not provide guidance for operating the pressure switches associated with the cooling tower clapper valves. To prevent recurrence, procedure changes have been made to verify pressure alarm switches are properly aligned and to check clapper valve supply pressures, in addition, the logs for the cooling towers have been revised to recuire nitrogen gas-bottle pressure to be recorded if a gas bottle is provicing system pressure, for this event, Technical Specification 3.7.11.1 requires the following Special Reports: a) notification by telephone within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />; b) confirmation by telegraph, mailgram or 1acsimile no later than the next working day; and c) submittal in writing within 14 days following the event. Telephnne notification was made on 8-7-91 and a facsimile report was also transmitted on 8-7-91. This Special Report completes the notification requirements of Technical Specification 3.7.11.1.

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