ML19246A720
| ML19246A720 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 05/18/1979 |
| From: | Short T OMAHA PUBLIC POWER DISTRICT |
| To: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| NUDOCS 7907060268 | |
| Download: ML19246A720 (3) | |
Text
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CENTRAL FILES PDR:HQ LEDR e@.lEn flSIC rS Omaha Public Power District 1623 HARNEY a
OMAHA, NEDRASKA 60,02 u TELEPHONE 536.4000 AREA CODE 402 May 18, 1979 Mr. K. V. Seyfrit, Director U. S. Nuclear Regulatory Co nission Office of Inspection and Enforcement Region IV 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76011
Reference:
Docket No. 50-235
Dear Mr. Seyfrit:
The Omaha Public Power District received IE Bulletin 79-09, dated April 17, 1979, requesting certain information in regard to the use of GE Type AK-2 circuit breakers in safety-related systems at the Fort Cal-houn Station. Accordingly, the requested information is attached.
Sincerely,
)
J
- n. Shor Assistant General Ihnager TE3/KJM/BJ9:jtm Attach.
cc:
URC Office of Inspection and Enforcetent Division of Reactor Operations Inspection Wash?ngton, D. C.
20555 LeBoeuf, Lamb, Leiby Ec MacRae 1757 "H" Street, H. W.
Washington, D. C.
20036 7 9 0 7 o n n 2c=E; r
'h p' 1
Ouestion 1 Detemine whether or not GE Type AK-2 circuit breakers are used or planned for use in safety-related systems at your facility.
Resoonse 1 AK-2 circuit breakers are used at the Fort Calhoun Station.
Questions 2 and 3 If such circuit breakers are used or planned for use, identify the safety systen involved and provide in written forn your plans for develop-ing a preventive maintenance program which vill assure design performance with the GE Type AK-2 circuit breaker.
The progran shall include as a nininum but not be limited to the fol-loving:
e.
Establish and adhere to a preventive maintenance schedule re-garding the subject circuit breakers.
b.
Have the maintenance performed by qualified personnel.
The GE power circuit breaker instruction canual should be used as guidance in setting up the maintenance procedures.
c.
During the preventive maintenance, perform the reco== ended corrective actions described in the enclosed GE Service Ad-vice Letter No. 175(CPDD)9.3, dated April 2, 1979 A copy of this letter is enclosed for your information and appro-priate use.
Responses 2 and 3 These circuit breakers are used in the entire h80 volt plant distri-bution system.
This distribution syste= enco= passes all station energency safeguards systers.
A conputerized preventive =aintenance program, which assures design perfor=ance of the GE ?ype AK-2 circuit breaker, has eeen establL hed.
This system requires preventive maintenance of the breaker and a calibration trip check on an every-other-refueling basis, with the high operating fre-quency breakers checked every year.
The raintenance schedule includes the following elecents:
a.
The schedule is adhered to and performed by qualified personnel.
b.
The GE pcVer circuit breaker instruction manual is used as guidance in setting up the maintenance procedures.
b
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_2_
Corrective actions described in the CE Service Advice Letter No.
175(CPDD)9 3, dated April 2,1979, vill not be performed since they are not applicable to the Fort Calhoun Station.
This is because the Fort Calhoun Station h80 switch gear does not use the undervoltage trip de-v3 ce addressed in the advice letter.
A much simpler shunt trip device is used.
This shunt trip device receives its trip signal from an IAV voltage relay, load shed, interlock, or manual switch.
It then, in turn, actuates the breaker cechanical trip techanism which opens the breaker.
m E
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