Nuclear Station in Connecticut Forced Offline after Steam Leakage in Stop Valves

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Researched by Industrial Info Resources (Sugar Land, Texas)--Dominion Resources Incorporated (NYSE:D) (Richmond, Virginia) was forced to take a large unit offline at the Millstone nuclear plant over the weekend after a mechanical failure as engineers performed a brief test on the stop valves. During the test, engineers discovered steam leakage, which required the removal of the 882-megawatt (MW) Unit 2. Maintenance crews suspect that the primary cause was due to a mechanical failure on both of the feedwater pumps. In a nuclear-powered steam turbine unit, the pumps are important components of the condensate feedwater system. This system has two primary functions with the feedwater pumps supplying the steam generator with purified water while the condensate system heats the water up to 450 degrees Fahrenheit. This high-pressured heated water is required to produce adequate steam for the turbine. Malfunctions in either of the components normally results in a significant reduction in capacity or the unit's complete removal. Engineers hope to have the issue resolved this week.

Located in Waterford, the Millstone plant is the only nuclear generating facility in Connecticut. The station consists of two units with a maximum capacity of 2,037 MW. Unit 3 has a maximum capacity of 1,155 MW. The station also has a 14-MW combustion turbine unit that is used primarily as an emergency generator.

Dominion is a producer and transporter of energy. The company's portfolio of assets includes approximately 26,500 MW of generation and 1.1 trillion cubic feet of natural gas and oil reserves. The company operates in three segments: Dominion Virginia Power, Dominion Generation and Dominion Energy.

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