ML19263D746
| ML19263D746 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 04/09/1979 |
| From: | Roe L TOLEDO EDISON CO. |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| 494, NUDOCS 7904130215 | |
| Download: ML19263D746 (2) | |
Text
- s I
UU April 9, 1979 gg Serial No. 494 LOWELL E. ROE Docket No. 50-346 ll;,';'ll;,',*,,,,
14191 259 S242 Licetise No. NPF-3 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 No. I to the staff positions concerning diesel generator lockout requested by your letter of March 6, 1979.
Very truly yours, s
b, /
LER:TJM bt d/3-4 Attachment 790413 0 A /5 S
\\
i THE TOLEDO EOISON COMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO, OHIO 43652
April 9, 1979 Serial No. 494 License No. NPF-3 Page 2 RESPONSES TO NRC STAFF POSITIONS ON DIESEL GENERATOR LOCK 0UT FOR THE 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 emergency dicscl 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 dicscl generator 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 DG TRBL TRIP".
We will reword this alarm to reId: "EMERG DG LOCK-0UT AND TRBL TRIP".
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 operation. 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 arc 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.