SCRIBA, NY – On November 3 at 8:23 a.m. Nine Mile Point Unit 1 experienced an automatic reactor shutdown.
The shutdown was caused by a water level change in the reactor pressure vessel. The transient began with a control system failure associated with the Feedwater System.
The plant responded according to design and automatically shut down with all safety systems responding appropriately.
The plant is in a safe and stable condition, according to Jill Lyon, CENG spokesperson.
“Our Operators, using detailed procedures and their training, took the appropriate actions to respond to plant conditions. Reactor water level has been restored,” she said.
All nuclear power plants are designed with a defense-in-depth approach to ensure safety. As such, they are designed to automatically shut down in response to certain indications and conditions.
The unit had been at 25% power when the shutdown occurred.
The unit had been synchronized to the grid earlier today at 5:56 a.m. following last Monday’s automatic shutdown due to the electrical disturbance in the switchyard.
“Our Outage Control Center was staffed supporting power ascension. The unit will be returned to service when the required work scope has been successfully completed and tested,” Lyon added.
Unit 2 continues to operate safely at 100% power and was not affected.