The renovation will enable the power plant’s two nuclear reactors to remain in operation until 2058 and 2060.

North Anna supplies 2,000 megawatts of electricity to the grid, enough to power 500,000 homes. That’s about one-sixth of all the energy Virginia’s consumers receive.

The result of the four-year review by the Nuclear Regulatory Commission was a 485-page safety report covering a range of topics: the plant’s mechanical and electrical systems, metal fatigue, plant structures and operating standards.

The review also produced a 444-page environmental impact statement that analyzes, among other things, how Dominion handles radioactive material, what cooling water the plant uses and its impact on surrounding land. It also examines the impacts and feasibility of generating electricity using other methods.

Among the major improvements Dominion has made at North Anna is the replacement of the main generators. The generators generate electricity using superheated, high-pressure steam from the nuclear reactors. Dominion is also replacing the main condensers, which recycle the steam to maintain a continuous process.

Other major investments include refurbishing reactor coolant pumps and converting instrumentation and control systems from analog to digital, Dominion spokesman Tim Eberly told the Richmond Times-Dispatch.

In addition, the company is implementing 80 improvements to station procedures, such as additional inspections and equipment testing.

The North Anna Power Plant, on the south shore of Lake Anna in Louisa County, about 5 miles southeast of Lake Anna State Park, has two nuclear reactors that began operation in 1978 and 1980.

Their original operating license was for 40 years. In 2003, after a similar review, the Nuclear Regulatory Commission extended their licenses for another 20 years, allowing them to operate until 2038 and 2040.

“With this 20-year extension, our customers can continue to count on North Anna for reliable, carbon-free energy for the next generation,” Eric Carr, Dominion Energy’s chief nuclear officer, said in a statement. “North Anna operates 24/7, generating the reliable, clean energy that powers our customers’ homes and businesses every day.”

Dominion’s other nuclear power plant, in Surry County, received a license extension in 2021 that allows it to operate until 2053.

Together, the two plants generate 40% of Virginia’s electricity and are responsible for about 90% of Virginia’s carbon-free energy.

“For more than 50 years, nuclear power has been the most reliable workhorse of our fleet and the largest source of carbon-free energy in Virginia,” Carr said.

The U.S. Nuclear Regulatory Commission has granted a license for a third plant in North Anna. Dominion says it has not committed to building the new plant but wants to retain the option to do so in order to meet the projected rapidly increasing demand for electricity in Virginia.

It would be a different type than the current pressurized water reactors in North Anna and would have an output of 4,500 megawatts, according to the approval documents with the Nuclear Regulatory Commission.

Meanwhile, at North Anna, Dominion is taking the first critical step toward bringing a new type of nuclear technology to Virginia: a small modular reactor that is less than a third the size of existing and expensive power plants like North Anna.

Smaller size and standardized parts are considered a means of reducing the cost of building nuclear power plants.

Dominion Energy’s affiliates also plan to seek approval to extend the operating licenses of two other nuclear power plants, the VC Summer Power Station in South Carolina and the Millstone Power Station in Connecticut, to 80 years.