ML19270G396

Submits Response to 790306 Request Re Diesel Generator Lockout

ML19270G396
Person / Time
Site:	Davis Besse
Issue date:	05/30/1979
From:	Roe L TOLEDO EDISON CO.
To:	Reid R Office of Nuclear Reactor Regulation
References
NUDOCS 7906060272
Download: ML19270G396 (2)

Text

s . ,

TOLEDO

%me EDISDN LOWELL E. ROE Docket No. 50-346 y,,,,,,,,,,,,

License No. NPF-3 [],*[,**3,.,' 'l, Serial No. 514 May 30, 1979 Director of Nuclear Reactor Regulation Attention: Mr. Robert W. Reid, Chief Operating Reactors Branch No. 4 Division of Operating Reactors United States Nuclear Regulatory Commission Washington, D. C. 20555

Dear Mr. Reid:

Attached are responses for the Davis-Besse Nuclear Power Station, Unit 1 to the staff positions concerning diesel generator lockout requested by your letter of March 6, 1979.

Response to position 2, previously transmitted to you on April 9,1979, has been revised as requested in a telephone conversation with Mr. G. Vissing of your staff on April 30, 1979.

Very truly yours, LER:TJM Attachment 2274 325 kCCS S

- ,cemc ec~ cc_ mec~ _ e _ec~ _m 1cmce c_eeee i 790606027R g

Docket No. 50-346 License No. NPF-3 Serial No. 514 May 30, 1979 RESPONSES TO NRC STAFF POSITIONS ON DIESEL GENERATOR LOCK 0UT FOR Tile DAVIS-BESSE NUCLEAR POWER STATION UNIT NO. 1 POSITION 1: "All shared annunciators for disability conditions should not be able to be cleared until all abnormal conditions are corrected."

RESPONSE: Davis-Besse Unit 1 cmergency diesel generator annunciators are in total compliance with Position 1.

POSITION 2: "If a diesel generator is provided with a manual shutdown lockout relay, an alarm should be provided which is worded to clearly indicate the diesel generr.cor is incapable of an automatic start when the relay is not set."

RESPONSE: The annunciator window which alarms the condition that the safety shutdown lockout relay is not reset is presently inscribed: "EMER DC TREL TRIP". We will reword this alarm to read: "EMERG DG LOCK-0UT OR TRBL TRIP". This will clearly indicate the diesel generator is incapable of an automatic start. The station's alarm procedures will also reflect this condition.

POSITION 3: "An alarm should be provided which clearly indicates when the diesel generator control switch is not in the automatic position."

RESPONSE: The diesel generator voltage regulator control switch must be in the "0N" position for automatic creration. We propose to add a signal to the annunciator described in Position 2 response, given above, which will cause it to alarm when the voltage regulator control switch is off.

There is no control switch which removes the auto-start capability of the diesel generator. To prevent a start of the diesel generator during maintenance, the starting air supply and fuel supply are shut off by closing hand operated valves. These valves are shown in FSAR Figure Number 9-15A, This operation is strictly controlled by Plant Maintenance Procedure, AD 1844.00 and Safety Tagging Procedure AD 1803.00.

2274 326 Revised May 30, 1979