STP to shut down one reactor temporarily

The South Texas Project nuclear power plant near Bay City will temporarily shut down one of its two reactors to repair part of the steam system that drives the electric generating turbines.
Power output in Unit 2 at the plant dropped by about 55 megawatts on Friday evening, said plant spokesman Buddy Eller, which led to the discovery of a leak in an expansion bellows in the main steam condenser. The bellows, which are not related to the reactor’s safety systems, are designed to expand and contract and are only accessible when the unit is shut down.
A similar problem was discovered earlier this year, leading to a 14 megawatt drop in output, but the issue had resolved itself, so it was determined at the time the unit could continue running.
The unit usually generates about 1,350 megawatts, enough power for about 1 million homes.
The company wouldn’t say how long it expects the repair to take for competitive reasons.
Full text of the release is below:

STP Unit 2 Going Offline Temporarily
Wadsworth, Texas – Sept. 16, 2009 – STP Unit 2 is being taken offline temporarily for maintenance on the plant’s extraction steam system. The repair is not related to the unit’s reactor or safety systems.
Degradation of a non-safety related expansion bellows in the main condenser of Unit 2 has resulted in a loss of overall efficiency of the unit and warrants a proactive repair. The bellows are designed to expand and contract based on steam pressure and temperature, and are only accessible when the unit is shut down.
“The safe and reliable operation of our units is always our top priority,” STP Chief Nuclear Officer Ed Halpin said. “We are taking a proactive, conservative approach to addressing this condition.”
STP is an industry leader in safety and production. The two-unit facility has operated for more than two years without an accident or injury among its 1,200 employees and contractors, and is an industry leader in overall personal safety. STP established an industry record in October 2008 when it completed a fourth consecutive production run by operating both units continuously between refuelings, which are 18 months apart.
“Our focus is always safety over production,” said Halpin. “Our team is poised to safely and effectively implement repairs.”
STP supplies approximately 7.5 percent of the electricity used in Texas. The plant is managed by the STP Nuclear Operating Company and owned by Austin Energy, CPS Energy and NRG Texas. STP’s twin reactors produce 2,700 megawatts of electricity, enough for nearly two million homes.
To learn more about the South Texas Project, visit