Nuclear refueling outage days in the U.S. 1995-2023

As of October 2023, the number of refueling outages for nuclear power plants in the United States stood at 35 days, up from 30 in 2021. On average, refueling outages lasted longer before 2013. Their duration was above 40 days per year in the 1990s, peaking at 80 in 1997.

Why are refueling outages needed?

Since spent fuel rods are no longer useful in sustaining a nuclear reaction, nuclear units are required to dispose of the spent fuel rods and conduct other routine maintenance and repair activities. Daily nuclear outages in the U.S. are scheduled for the months of low energy demand, such as April and October, when the loss in nuclear capacity can amount to 20 gigawatts as a daily average.

Electricity mix of the U.S.

U.S.’s electricity needs are met by a selection of energy carriers including natural gas, coal, oil, and renewable sources as well as nuclear energy. Despite the wide variety of fuels that can be used, U.S.’s power generation mix consists primarily of fossil fuels to provide its citizens with an around-the-clock “baseload” supply of electricity.