ML20204D712
| ML20204D712 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 05/18/1979 |
| From: | Jeffery Grant TOLEDO EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| FOIA-79-98 IEB-79-05A, IEB-79-05B, IEB-79-5A, IEB-79-5B, NUDOCS 7907050015 | |
| Download: ML20204D712 (2) | |
Text
-
f G 0tLlN.$lsL Y
~)%oSA/B Oy1 TOLEDO
%m EDISON y JAMES S. GRANT v...,.....
May 18, 1979 p.re, s..,
m e nee. ors, Docket No. 50-346 License No. NPF-3 Serial No. 1-68 L..
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 further respond to IE Bulletin 79-05B for the Davis-Besse Nuclear Power Station Unit 1.
The attached page 3-1 addresses item 3 of the Bulletin whose response is required prior to Davis-Besse Unit I resuming operation.
Additionally, minor changes are being incorporated into the station's procedures to reflect revisions to Babcock and Wilcox's operating guidelines. These change.=
were made as a result of NRC comments and alter, in part, item 2 of the May 4, 1979 (Serial No. 1-65) response.
Yours very truly, JSG:TJM Attachment cc:
U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Division of Reactor Operations Inspections Washington, D.C. 20555 S
.qqo105M' p
THE TOLEDO EDICON COMPANY EDISON PLAZA 300 MAOISON AVENUE TOLEDO. OH10 43652
as.,
Docket No. 50-346
,*,,, Lie:2se No. NPF-3
> Serial No. 1-68 Item 3 Following detailed analysis, describe the, modifications to design s ad procedures which you have implemented to assure the reduction of the likelihood of automatic actuation of the pressurizer PORV during anticipated transients.
This analysis shall include consideration of a modification of the high pressure scram setpoint and the PORV opening setpoint such.that reactor scram will preclude opening of the PORV'for the spectrum of anticipated transients discussed by B&W in Enclosure 1.
Changes developed by this analysis shall not result in increased frequency of pressurizer safety valve operation for these anticipated transients.
Response
l Evaluations of the Davis-Besse Nuclear Power Station Unit 1 (DB-1) were performed to consider modifications which would assure the reduction of the likelihood of automatic actuation of the pressurizer PORV during anticipated transients.
The resuits of these evaluations identified that coincident reduction of the high 4
reactor coolant system (RCS) pressure trip setpoint and elevation of the PORV setpoint would resolve this. At Davis-Besse Unit 1, the high RCS pressure trip is to be reduced from a nominal 2355 psig to-2300 psig.
The PORV opening setpoint is to be raised to 2400 psig.
This will assure the reduction of the likelihood of aut natic actuation of the pressurizer PORV during anticipated transients.
It shotid be noted that Davis-Besse Unit I has nominal pressurizer code safety valve Aift settings of 2435 psig in accordance with " Davis-Besse Nuclear Power l
Station Unit 1 Technical Specifications" No. 3.4.3.
I i
c 9
e e B
b