See event # 40223, Part 21 reported on 10/04/03 by
GE Nuclear Energy for background information.
On October 5, 2003, Progress Energy Carolinas, Inc. received notification from General Electric of a Part 21 involving the potential for numerous, unexpected confirmation count (CC) resets in the event of an instability condition. These CC resets may result in the inoperability of TS Table 3.3.1.1-1,'Reactor Protection System Instrumentation, Function 2. f, OPRM Upscale.'
All Unit 1 and Unit 2 OPRM channels have been declared inoperable. Technical Specification 3.3.1.1, Action I requires an alternate method of detecting and suppressing thermal hydraulic instabilities to be implemented within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The alternate methods of detection and suppression are currently in place.
Due to the implementation of Technical Specification required compensatory actions, there is minimal safety significance.
The NRC Resident Inspector was notified of this event by the licensee.
Also see similar events reported by
NMP Unit 2 (event # 40217) and Fermi Unit 2 (event # 40215)