The plant was named after Robert Emmett Ginna, a former chief executive of
Rochester Gas & Electric, who was one of the nation's earliest advocates of using nuclear energy to generate electricity. Ginna is owned and operated by
Constellation Energy following separation from
Exelon in 2022. Constellation, prior to merger with Exelon purchased it from Rochester Gas and Electric in 2004. The Ginna plant was the site of a
nuclear accident when, on January 25, 1982, a small amount of
radioactive steam leaked into the air after a steam-generator tube ruptured. The leak, which lasted 93 minutes, led to the declaration of a site emergency. The rupture was caused by a small pie-pan-shaped object left in the steam generator during an outage. This was not the first time a tube rupture had occurred at an American reactor but following on so closely behind the
Three Mile Island accident caused considerable attention to be focused on the incident at the Ginna plant. In total, 485.3 curies of noble gas and 1.15 millicuries of iodine-131 were released to the environment and of contaminated water was lost from the reactor. In 1996 the original Westinghouse supplied steam generators (including the one that was damaged in 1982 and repaired) were replaced by two brand new
Babcock & Wilcox steam generators. This project enabled an uprating of Ginna's output several years later and was a major factor in the approval of the plant's operating license extension for 20 years beyond the original license (originally valid until 2009). == Electricity production ==