ML19270G413
| ML19270G413 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 05/15/1979 |
| From: | Jeffery Grant TOLEDO EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 1-67, IEB-79-05A, IEB-79-05B, IEB-79-5A, IEB-79-5B, NUDOCS 7906060291 | |
| Download: ML19270G413 (2) | |
Text
.
'79 TOLEDO
.% EDISON JAMES S. GRANT May 15, 1979 v'c. Pres dent Energy Suposy (4191 259-5232 Docket No. 50-346 License No. NPF-3 Serial No. 1-67 Mr. James G. Keppler Regional Director, Region III Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
Dear Mr. Keppler:
This letter is to identify a change in the Davis-Besse Nuclear Power Station Unit 1 respoase to 1E Bulletin 79-05B, item 4.
Enclosed is page 4-1 that revises Toledo Edison's >Sy 4, 1979 (Serial No. 1-65) transmittal.
The effect of the change is that Davis-Besse Unit 1 procedures will not now be modified to provide a manual reactor trip on low pressurizer level. This is a more proper response, because low pcessurizer level is associated with underpressurization rather than overpressurization events. A reactor trip would only aggravate the problem during an underpressurization event as it removes the primary heat source; therefore, our current procedures calling for increasing reactor coolant makeup on decreasing level will be uneffected.
The reactor core will continue to be protected by the low RC pressure trip as analyzed in the FSAR.
Yours very truly,
/A//e 2275 347 JSG:TJM/pm enc.
cc:
U. S. Nuclear Regulatory Co= mission Office of Inspection and Enforcement Division of Reactor Operations Inspection jdf g)g)g,; j{
Washington, D. C.
20555 lf a THE TCLECO EDISCN CCMPANY ECISCN PLAZA 3C0 MACISCN AVENUE TCLECO. CH10 43652 790606079l
c Docket No. 50-346 License No. NPF-3 Serial No. 1-67 May 15, 1979 Item 4 Provide procedures and training to operating personnel for a prompt manual trip of the reactor for transients that result in a pressure increase in the reactor coolant system. These transients include:
a.
Loss of main feedwater b.
Turbine trip c.
Main Steam isolation Valve closure d.
Loss of off-site power e.
Low OTSG level f.
Low pressurizer level
Response
A hard wired reactor trip on the loss of main feedwater and on a turbine trip will be installed prior to Mode 3 operation. Procedures will be prepared and the operators will be instructed to manually trip the reactor on the closure of the main steam line isolation valve, and on low steam generator levels, prior to Mode 3 g
operation. Procedures will be prepared and the operators will be trained to confir.-
that the reactor has aut,matically tripped upon a total loss of off-site power which has forced the Emery,
Die,el Generators to start.
However, if the main turbine gen-:rator is isolated f rom the 345 KV transmission system and it is supplying the unit's house power (including reactor coolant pumps), then the reactor will not be manually tripped.
If the reactor were tripped under this condition, the main turbine generator would a2s> be tripped which would result in an unnecessary momentary loss of AC power, which would force the Emergency Diesel Cencrators to start.
Also, this tripping would case the loss of forced reactor coolant circulation.
2275 348 4-1 Revised May 15, 1979
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