Kewaunee Power Station

The Kewaunee Power Station is a partially-decommissioned nuclear power plant, located on a 900 acres (360 ha) plot in the town of Carlton, Wisconsin, 27 miles (43 km) southeast of Green Bay, Wisconsin in Kewaunee County, and south of the city of Kewaunee.

KPS was the third nuclear power plant built in Wisconsin, and the 44th built in the United States. Due to falling electricity prices resulting from the falling price of natural gas, the plant ceased operation May 7, 2013.^[3]

On January 20, 2026 a Notice of Intent (NOI) was submitted by site owners EnergySolutions to the Nuclear Regulatory Commission (NRC) confirming their intent to submit an application for major licensing action for new nuclear generation at the Kewaunee site. This initiative was first announced in May 2025 and the application is expected to be submitted in 2028.^[4]

The plant's original operator was Wisconsin Public Service and it was owned by Wisconsin Public Service Corporation (59%) and Alliant Energy (41%).^[5] From 2000 to July 2005, the plant was operated by Nuclear Management Company, of Hudson, Wisconsin. The plant was then sold to Dominion Resources of Richmond, Virginia. In 2008, Dominion applied to the NRC for an extension of its operating license for an additional 20 years.^[5] The license was extended until 2033.

On April 27, 2006, there was a small water leak at the plant, though no radioactive material was released.^[6]

On October 22, 2012, Dominion Resources announced they would shut down and decommission the plant in mid-2013. Dominion's chairman and CEO said "the decision was based purely on economics. Dominion was not able to move forward with our plan to grow our nuclear fleet in the Midwest to take advantage of economies of scale". Lower natural gas costs and resultant lower electricity prices created an electricity market in which the plant could not compete. The plant came offline permanently on May 7, 2013.^[3][7] Plans for decommissioning were uncertain: as a private owner rather than a public utility, Dominion could not rely on charges imposed on utility customers by state regulators; however, the firm had a substantial reserve fund earmarked for this purpose and a cause of action against the Department of Energy for failure to remove spent fuel. There was also the chance that the energy market might improve due to economic or political changes.^[3]

The SAFSTOR (SAFe STORage) nuclear decommissioning option was selected. During SAFSTOR, the de-fuelled plant is monitored for up to sixty years before complete decontamination and dismantling of the site, to a condition where nuclear licensing is no longer required. During the storage interval, some of the radioactive contaminants of the reactor and power plant will decay, which will reduce the quantity of radioactive material to be removed during the final decontamination phase. A reduced workforce will move fuel assemblies from the reactor into the spent fuel pool.^[8]

On July 15, 2017, as part of decommissioning effort, the remaining fuel assemblies were successfully transferred to 24 Magnastor casks. Pool-to-pad work was completed in 23 weeks. The entire used fuel inventory from nearly four decades of electricity generation at Kewaunee is represented by the 24 Magnastor systems and 14 legacy Nuhoms systems.^[9]

An agreement to acquire the site and complete the decommissioning activities was reached between Dominion and EnergySolutions of Salt Lake City, UT in May 2021. EnergySolutions had previously completed the decommissioning of the La Crosse Boiling Water Reactor, Wisconsin's first commercial nuclear facility.^[10] The sale of the plant was approved by the federal government in March 2022 as well as by the Public Service Commission of Wisconsin (PSC) in June 2022.^[11][12] Prior plant owners WPSC and WP&L were given right of first refusal (ROFR) to repurchase the non-operational site, but both utilities waived this right during the PSC proceedings.^[12]

As of December 31, 2024, the Kewaunee Decommissioning Trust Fund (DTF) balance was $752.4M and the remaining decommissioning work was estimated at $712.8M.^[13]

Dating back to 2001, peregrine falcons nested at the facility, near the top of the containment structure. At least 53 young were produced in that time (2.4 young per year). The nest was taken over by great horned owls in 2022 and has since been deconstructed.^[14][15]

* Power station went offline (start of decommissioning phase)

This plant had one Westinghouse pressurized water reactor. The plant site has two 345 kV lines interconnecting to the grid with one going to We Energies North Appleton Substation located 15 miles (24 km) north of Appleton, Wisconsin and the other one interconnecting with the Point Beach Nuclear Generating Station located just a short distance away. Two 138 kV lines exit the plant which go to the Green Bay area 30 miles (48 km) away.

The NRC defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone with a radius of 10 miles (16 km), concerned primarily with exposure to, and inhalation of, airborne radioactive contamination, and an ingestion pathway zone of about 50 miles (80 km), concerned primarily with ingestion of food and liquid contaminated by radioactivity.^[17]

The 2010 U.S. population within 10 miles (16 km) of Kewaunee was 10,292, a decrease of 0.9 percent in a decade, according to an analysis of U.S. Census data for msnbc.com. The 2010 U.S. population within 50 miles (80 km) was 776,954, an increase of 10.1 percent since 2000. Cities within 50 miles include Green Bay (26 miles to city center).^[18]

The Nuclear Regulatory Commission's estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at Kewaunee was 1 in 83,333, according to an NRC study published in August 2010.^{[19] [20]}

• "Wisconsin Nuclear Plants#Kewaunee". Energy Information Administration, U.S. Department of Energy (DOE). September 1, 2010. Retrieved 2011-03-17.
• "Kewaunee Pressurized Water Reactor". Operating Nuclear Power Reactors. U.S. Nuclear Regulatory Commission (NRC). February 14, 2008. Retrieved 2008-11-20.
• kewauneesolutions.com, a website set up by the 2022 purchaser of the plant; link has unnarrated videos depicting the exterior and interior of the facility, including aerial videos