Turbine Generator Trip Causes Reactor to Shut Down at Grand Gulf Nuclear Station in Mississippi

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Researched by Industrial Info Resources (Sugar Land, Texas)--The Grand Gulf Nuclear Power Station, which is located in Port Gibson, Mississippi, has been offline since about 2:30 p.m. CDT on June 30 due to an unscheduled mechanical maintenance outage. The station is owned by Entergy Corporation (NYSE:ETR) (New Orleans, Louisiana).

Sources said that the turbine generator control valve malfunctioned in the 1,201-megawatt (MW) Unit 1. This caused the reactor pressure to increase to unacceptable levels, which then triggered the reactor protection system (RPS).

There was no loss of off-site power, and the emergency core cooling system did not have to initiate. However, the reactor core isolation cooling (RCIC) system was initiated and injected. The safety relief valves were not triggered, and the main steam isolation valves remained open.

Currently, the unit is in a "Hot Shutdown" mode, which means that the reactors must be cooled and everything brought to a halt. The main turbine bypass valves are controlling reactor pressure to the main condenser, and there are no challenges to primary or secondary containment at this time. Plant officials are hoping to bring the unit back online by the end of the week.

The Grand Gulf Nuclear Power Station currently has one unit. The station is awaiting the NRC's approval for a second unit.

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