An energy company is looking into the possibility of building a small nuclear plant in South Dakota.
The company, NorthWestern Energy, is targeting a potential construction date in 2030. The plant would produce between 80 and 320 megawatts. Conventional, large nuclear reactors can produce over 700 megawatts.
“A decision has not been made whether or not to build a plant,” said Jeff Decker, NorthWestern regulatory specialist. He addressed a meeting of the state Public Utilities Commission on Tuesday in Pierre.
The estimated cost is $1.2 billion to $1.6 billion for a 320-megawatt plant. The company said it has two potential sites, but those locations are confidential.
It would be South Dakota’s first nuclear plant since a test facility was briefly operated near Sioux Falls in the 1960s.
NorthWestern told the commission in a document that the need for nuclear power comes as “we are concerned about a number of factors outside of our control that may force us into early retirement of our coal‐based generation facilities.”
“This plant will provide the necessary 24/7 reliability that is needed for NorthWestern’s customers as the existing coal plants in South Dakota are retired,” Decker said in a document submitted to the commission.
To be eligible for federal Department of Energy funding, NorthWestern said it must complete parts of a study by May.
On Tuesday, NorthWestern received permission from the commission to defer the costs of conducting the study. The study costs will accumulate in an account, and the company will eventually seek the commission’s approval to charge those costs to customers “over a period of time instead of passing them on to customers immediately,” NorthWestern said in a document.
The commission is allowing NorthWestern to keep the study costs and timeline confidential for at least 10 years, on the grounds that the project development details are proprietary.
NorthWestern provides electricity or natural gas to 764,200 customers in Montana, South Dakota, Nebraska and Yellowstone National Park.
The 2023 South Dakota Legislature is also interested in nuclear energy. The House and Senate recently passed a resolution encouraging the Legislature’s Executive Board to appoint a summer study committee to “examine the potential use of nuclear power in South Dakota, to include a nuclear power plant, for the establishment of a safe, clean, and reliable source of energy for South Dakota.”
Meanwhile, a proposal to mine near Edgemont for uranium, which is the element used as fuel in nuclear power generation, has been stuck in regulatory review for more than a decade.
Traditional nuclear power plants work by splitting uranium atoms to release energy. Heat from that energy is used to turn liquid into steam, and the steam is used to spin turbines and generate electricity. Nuclear energy does not produce large amounts of greenhouse gas emissions like other forms of energy such as coal and natural gas, but nuclear power production does produce radioactive waste that must be safely controlled and stored.
