The firm has notified the US federal Nuclear Regulatory Commission (NRC) to file a 20-year license renewal application for its two-unit North Anna power station in 2020.

In 2015, Dominion also notified the NRC its intention to relicense the 1,676MW two-unit Surry nuclear power plant and to submit 20-year license renewal application in the spring of 2019.

Dominion nuclear generation division chief nuclear officer Daniel Stoddard said: "Renewing North Anna Power Station's licenses for a second 20-year period is the right thing to do for our customers, the regional economy and the environment.

"The planned relicensing of North Anna and Surry ensures that the benefits of these clean energy sources will continue to provide affordable, reliable, carbon-free electricity to our customers through the middle of the century.

"The operation of North Anna and Surry also positions Virginia for economic growth. It directly supports more than 2,000 high-paying jobs in Virginia and produces additional economic and tax benefits.”

The unit 1 of North Anna Power Station was commissioned in 1978, while the unit 2 entered service in 1980.

The company plans to invest up to $4bn on upgrades to the relicensing process of North Anna and Surry power plants, which were originally licensed to operate for 40 years.

The current licenses of units 1, 2 of North Anna and Surry nuclear plants are scheduled to expire in 2038 and 2040, and 2032 and 2033 respectively.

Upon renewal, the operating licenses for the two units at North Anna and Surry will extend to 2058 and 2060, and 2052 and 2053 respectively.

Dominion Energy also operates two nuclear units at its Millstone Power Station, located in Waterford, Conn. In 2005, it renewed the station's operating license for one 20-year term, extending the current license for unit 2 and unit 3 to 2035, and 2045 respectively.

Image: The North Anna nuclear generating station in Virginia, US. Photo: courtesy of dougward from Devon, United States/Wikipedia.