Dominion Mulls Millstone's Future as Kewaunee Closure Advances

Employees working to permanently decommission Dominion Energy's 556 megawatt (MW) Kewaunee nuclear power station in Wisconsin moved the last of the facility's used nuclear fuel in mid-June to a dry fuel storage facility located on site.

In a related development, news reports say that Dominion told the New England Independent System Operator (ISO) that it might close its Millstone station in Connecticut as early as 2022 due to what it says are unfavorable market conditions. ISO New England reportedly told the utility it may also elect to transfer responsibility to provide energy to a third party or pay a penalty to exit the market early.

Under New England ISO rules, a power plant operator can indicate that it will not remain open by not participating in the ISO's forward capacity auction market. That signal normally comes no less than four years in advance of a plant's retirement. The forward capacity market pays power plants to ensure their energy will be available years in advance.

Millstone Units 2 and 3 are pressurized water reactors (one from Westinghouse and one from Combustion Engineering) and have a combined generating capacity of 2,037 MW. They were sold to Dominion Resources by Northeast Utilities in 2000.

In Wisconsin, meanwhile, Dominion permanently closed the Kewaunee nuclear station in May 2013 due to economic challenges including a weak electrical market.

The plant began commercial operation in 1974. It operated one Westinghouse pressurized water reactor. Dominion acquired the station in July 2005. In February 2011, the NRC renewed the station's operating license for an additional 20 years, until 2033.

Under the U.S. Nuclear Regulatory Commission's regulatory requirements for the SAFSTOR decommissioning option – chosen by the company for the Kewaunee station – radiological contamination must be safely removed and sent to a facility authorized to accept the material within the 60-year period.

Dominion Energy operates three nuclear power stations – the Millstone Power station in Waterford, Conn., and the North Anna and Surry power stations in Louisa and Surry counties, Va., respectively.