ML19322B764
| ML19322B764 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 12/31/1976 |
| From: | Parker W DUKE POWER CO. |
| To: | Moseley N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 7912050760 | |
| Download: ML19322B764 (2) | |
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DUKE POWER COMPANY Powen Bt:stDxxo
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December 31, 1976
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Tc. c.-e ~ c aac. 7:4 St ca= Noose' ion 373-4093 Mr. Norman C. Moseley, Director U. S. Nuclear Regulatory Commission Suite 818 230 Peachtree Street, Northwest Atlanta, Georgia 30303 Re: Oconee Nuclear Station Docket Nos. 50-269, -270, -287
Dear Mr. Moseley:
The purpose of this letter is to inform you of the status of several commitments which have been made in various correspondence to you.
Reportable Occurrence Report R0-287/76-12, transmitted by letter of September 17, 1976 concerned the loss of a 600 volt motor control center.
In the corrective action section of this report, a commitment was made to reroute the power supply to the Reactor Building Cooling Units (RBCU) by installing a separate power line and feeder breaker for the RBCU's between the motor control center and the load center.
Additionally, a study of the breaker coordination for 600 volt ES motor control centers and their respective load centers was to be performed.
These actions were to be completed by January 1, 1977. Subsequently, it was determined that rerouting of the power supply for the RBCU's should be deferred until the breaker coordination study was completed in order to possibly minimize the modifications necessary to the electrical system.
The breaker coordi-nation study has been completed and certain changes have been recommended.
Since these changes will necessitate the de-energization of the motor control centers, they will be implemented on each Oconee unit at their next respective refueling outages.
In response to OIE Inspection Report 50-269, -270, -287/76-11, our letter dated November 15, 1976 committed to the installation of final lighting along a short section of the protected area fence by January 1, 1977.
Equipment delivery schedules have made this schedule impossible.
It is now expected that this lighting will be installed by April 1, 1977.
Unresolved item 74-14/2 " Ventilation Control between Auxiliary and Turbine Buildings" was identified in OIE Inspection Report 50-269, -270,
-287/74-14. This item was identified by the inspector observing an indi-cation of some air flow from the Auxiliary Building to the Turbine Build-ing. The goal of maintaining the Auxiliary Building at a pressure lower
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P:gs 2 December 31, 1976 than its surroundings is to minimize the potential for unmonitored releases of radioactivity to the environment.
Subsequent to this identification, openings in the wall between the Turbine and Auxiliary Buildings have been more effectively sealed. The motors for two air handling units in the Auxiliary Building have been replaced with larger ones to increase the exhaust flow rate. Additionally, modifications to the Turbine Building to provide openings in the east wall have had the effect of increasing the Turbine Building pressure relative to the Auxiliary Building. These steps have significantly increased the probability that a negative Auxiliary Building pressure will be maintained and that essentially all releases from the Auxiliary Building will be through a monitored pathway. Therefore, a commitment made in an exit interview conducted on August 19, 1976 to increase the motor size of several other Auxiliary Building fans is not now considered necessary. Auxiliary Building pressure will be monitored for one month to document this fact.
Very,cruly yours, A
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' William O. Parker, Jr. f
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