ML20034E080
| ML20034E080 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 02/16/1993 |
| From: | Hampton J DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9302240420 | |
| Download: ML20034E080 (1) | |
Text
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Ddeher Company
, y.y
.Gmee &clearSite VicePresident P.0 Box 1439 (803)&%3499Olixe S,
$(gg (803)M535M Fax DUKEPOWER I
February 16, 1993 U.
S., Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Subj ect:
Oconee Nuclear Station Docket Nos. 50-269,-270,-287 Special Report, Technical Specification 3.7.9-Technical Specification (TS) 3.7.2(e)1 pemits complete single string or single-of the 230kV Switchyard 125VDC power system to be inoperable for 24 component hours.
In the event of degradation beyond TS 3.7.2, TS 3.7.9 requires notification of NRC Region II within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and submittal of a safety evaluation which justifies the safest course of action to be taken in the event of ongoing degradation beyond TS 3.7.2, together with plans for expediting the return to unrestricted operating conditions.
On February
.0, 1993 it was determined that the limits of TS 3.7.2.e.1 were exceeded on January 26,1993 when power was lost to both 230kV Switchyard battery chargers for approximately 30 to This occurred during a dead bus transfer as part of a Technical 40 minutes.
Specification required test during the Unit 1 tefueling outage. NRC Region II was notified of this event by telephone on February 10, 1993.
Although the event of concern has already been resolved, the following information provides the basis for the cvurse of action taken.
Briefly, upon discovery of low battery voltage during a routine surveillance,- the Oconee Unit 1230kV Switchyard feeder was restored, the battery chargers were verified to be and the batteries were verified to be operating at normal float operating, voltage.
Subsequent investigation determined that the chargers had been-deenergized for approximately 30 to 40 minutes.
Calculatio: s have been documented to show that the actual battery terminal voltages would be significantly greater than required if a switchyard isolate event were to occur following an assumed one hour discharge at normal loads.
Very Truly Yc,urs,
. W. Hampton xc:
L. A. Viens, Project Manager DNRR S. D. Ebneter, Regional Administrator Region II P. E. Harmon, Senior Resident Inspector g
9302240420 930216 PDR ADOCK 05000269 g
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