U.S. nuclear electric generation plant outages averaged 2.7 gigawatts (GW) during the summer of 2019 (June through August), about the same as during the summer of 2018. Nuclear plant availability was at its highest level, meaning that nuclear outages were at their lowest level from late June to early July, averaging 1.2 GW. Although the Three Mile Island Unit 1 retired in late September, daily nuclear outages that month were 67% lower than year-ago levels. Nuclear plants undergo planned outages, usually for maintenance and refueling, or unplanned outages, such as during hurricane-related disruptions.
