ML19317D492
| ML19317D492 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 08/23/1976 |
| From: | Parker W DUKE POWER CO. |
| To: | |
| References | |
| NUDOCS 7912060752 | |
| Download: ML19317D492 (2) | |
Text
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l Mr. Benard C. Rusche 4
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U. S. Nuclear Regulatory Co a
Washington, D. C.
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s Re: Oconee Nuclear Station Docket Nos. 50-269, -270, -287
Dear Mr. Rusche:
The Oconee Nuclear Station Technical Specifications 3.7, " Auxiliary Electrical Systems," provides Limiting Conditions for Operation relative to the Oconee Electrical System.
Previsions are made for operation in degraded modes for specified periods of time to perform maintenance or test or if equipment is not operable. Further, any degradation beyond the detailed conditions of the specification are required, by Specification 3.7.8, to be reported to the NRC Office of Inspection and Enforcement within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and a safety evaluation for the specific situation is to be performed by Duke Power Company. The results of this evaluation together with the plans for expediting the return to unrestricted operation shall be submitted to the NRC, Office of Nuclear Reactor Regulation within five days. The purpose of this letter is to describe a situation which has occurred at Oconee Nuclear Station and to provide the required written teport.
On August 18, 1976, at approximately 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />, it was determined that the Oconee Unit 3 125 volt DC instrumentation and control power system batteries (3CA and 3CB) had not been tested in accordance with Technical Specification 4.6.7.c within the specified surveillance time period.
This is a one-hour discharge test at the required maximum safeguards load.
Since these batteries had not been tested, they were considered inoperable based upon the definition " operable" in Specification 1.3.
An evaluation of this situation was performed.
It was determined that ten battery discharge tests have been performed at Oconee (four I&C battery tests for Oconee 1, two I&C battery tests for Oconee 2, two switchyard battery tests and two Keowee Hydro Station battery tests) with all batteries performing satisfactorily. The voltage and temperature 7 912 060 75~ m3
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o Mr. Benard C. Rusche Page 2 August 23, 1976 of pilot cells have been measured five times per week and the specific gravity and voltage of each cell have been measured monthly with no indications of battery degradation.
Annunciators provided in the control room give assurance of continued proper operation of tha battery chargers.
From the above tests and indications and a review of the service life and capacity of these batteries, it was concluded that the Oconee 3 instrument and control batteries should be capable of performing the one-hour test discharge at the required maximam safeguards load.
In view of the above discussion concerning the operability of the Oconee 3 I&C batteries and the fact that redundancy is provided to the Oconee 3 125 VDC I&C system from the Oconee 1 I&C batteries, it was considered that maintaining Oconee 3 at power was the safest course of action based upon the short period of time necessary to perform the test discharge and the minimization of maneuvering transients. Oconee 3 battery 3CB was removed fram service and the discharge test was completed by 1850 hours0.0214 days <br />0.514 hours <br />0.00306 weeks <br />7.03925e-4 months <br /> on August 18, 1976 with the battery restored to operable status by 1630, August 20, 1976. The 3CA battery was then removed from service and the discharge test was completed at 1925 August 20, 1976.
Battery 3CA was returned to operable status on August 23, 1976 following the battery charge.
It is considered thac the limiting conditions for operation specified in Technical Specification 3.7.1 are now being met.
Very truly yours, William O. Parker, Jr MST: r l
cc:
Mr. Norman C. Moseley l
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