ML19242C561

From kanterella
Jump to navigation Jump to search
Forwards Response to IE Bulletin 79-11.Westinghouse Type DB-50 & DB-75 Circuit Breakers Not in Use in safety-related Sys
ML19242C561
Person / Time
Site: Davis Besse Cleveland Electric icon.png
Issue date: 07/03/1979
From: Jeffery Grant
TOLEDO EDISON CO.
To: James Keppler
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
1-77, NUDOCS 7908100583
Download: ML19242C561 (2)


Text

9 AO[

. ys s

TOLEDO

%ms EDISON JAMES S. GAANT v.c. p,..... i e .rs , s.....

Dc:ket No. 50-346 me ass san License No. NPF-3 Serial No. 1-77 July 3, 1979 Mr. James G. Keppler Ragional Director, Region III office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Dear Mr. Keppler:

IE Bulletin 79-11 directed certain actions for plants utilizing Westinghouse type DB-50 and DB-75 circuit breakers in safety related systems.

Enclosed is our response to IE Bulletin 79-11 for the Da (s-Besse Nuclear Power Station, Unit No. 1.

Very truly yours, k_Y, r--

JSG:1KR Encl.

cc:

U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Divisicn of Reactor Operations Inspection Washington, D. C. 20555 599252 7908100 D3, O IS79 THE TCLECO EDISON CCMPANY EDISCN PLAZA 300 MACISON AVENUE TOLECO, CHIO 43652

  • '64 se Docket No. 50-346 License No. NPF-3 Serial No. 1-77 July 3, 1979 Items 1, 2 and 3 of Action Required:

Response : Not applicable since Westinghouse type DB-50 and DB-75 circuit breakers are neither used in safety related Class IE service nor are in spares at our facility.

Item 4: Review test procedures and test schedules for all safety related circuit breakers to assure that all such breakers are tested at least each refueling outage to confirm over-current time delay protection.

Response: All safety related circuit breakers used at our facility do not incorporate the dash pot system. A Solid State tripping unit is used for circuit breaker mounted overcurrent tripping. Remote relays functioning off of current transformers are used for ove rcurrent tripping functions which are not circuit breaker mounted.

The Station maintenance procedures require the testing of these circuit breakers at every refueling outage. The circuit breaker mounted trip devices are tested at every refueling outage. The remote relays for 480V circuit breakers are presently tested on a 48 month cycle. This will be changed to each refueling cycle and implemented im=ediately. Higher voltage Class IE circuit breakers remote relays are tested on a 12 month cycle.

530753