Dominion Virginia Power has selected the Mitsubishi Heavy Industries’ (MHI) US-APWR design as the prospective reactor for its proposed North Anna power plant expansion project.

The US utility currently operates two nuclear units at the North Anna site, located 72 km northwest of Richmond, Virginia and wants to construct a third unit there. It selected the US-APWR design by a competitive process involving bids from reactor vendors around the world.

MHI says that the reactor is among the world’s largest advanced-pressurized water reactors (APWR), capable of powering more than 360 000 US homes. In 2007, Texas-based Luminant selected the US-APWR design for its Comanche Peak Units 3 and 4 south of Fort Worth, Texas.

MHI developed the US-APWR based on technologies for a 1538 MW APWR intended for use at the Tsuruga Power Station (Units 3 and 4) of the Japan Atomic Power Company. A variety of modifications were added to meet the demands of US utility customers for enhanced performance, including the world’s highest level of thermal efficiency, a 20 per cent reduction in plant building volume, a 24-month fuel cycle and greater economy through increased power generation capacity.

To date MHI has built 24 pressurized water reactors in Japan and has exported numerous components for nuclear power plants to US utilities, including reactor vessel heads, control rod drive mechanisms and steam generators. MHI first entered the US nuclear market in 2002 through an order from Dominion for a replacement reactor vessel closure head and control rod drive mechanism at the Surry and North Anna nuclear plants, respectively.

Dominion must obtain a combined construction and operating license from the NRC as well as an agreement from Virginia State Corporation Commission to construct a new nuclear unit at North Anna.