Nuclear power plants owned by major U.S. investor-owned utilities spent an average of 23.89 mills per kilowatthour on operation, maintenance and fuel in 2025, compared with 42.12 mills for fossil steam plants, according to the U.S. Energy Information Administration's Electric Power Annual. A mill is one-tenth of a cent, so the nuclear figure equals about $23.89 per megawatthour.

Fuel accounted for the largest gap between the two plant types. Nuclear fuel expenses averaged 6.64 mills per kWh in 2025, while fossil steam fuel costs averaged 30.62 mills. Gas turbine and small-scale plants, a category that also includes wind and solar units, averaged 24.61 mills for fuel and 28.22 mills in total expenses.

Within the nuclear total, operation costs were 10.14 mills per kWh and maintenance costs were 7.10 mills in 2025. Hydroelectric plants, including pumped storage, averaged 16.43 mills in total expenses.

The EIA series shows nuclear operating expenses trending lower over the past decade. The total stood at 26.54 mills per kWh in 2015 and dropped to 22.83 mills in 2024 before rising slightly in 2025. Nuclear fuel costs fell from 7.70 mills in 2015 to a range of 6.10 to 6.64 mills over the past four years. The figures are weighted by net generation and come from utilities' Federal Energy Regulatory Commission Form 1 filings.

A separate Statista chart of Lazard estimates as of June 2025 puts the levelized cost of power from fully depreciated U.S. nuclear plants at $34 per MWh, compared with a range of $141 to $220 per MWh when construction costs are included.

Source: U.S. Energy Information Administration -- https://www.eia.gov/electricity/annual/html/epa_08_04.html