The Callaway Plant is a nuclear power plant located on a site in Callaway County, Missouri, near Fulton, Missouri. It began operating on December 19, 1984. The plant, which is the state's only commercial nuclear unit, has one 1,190-megawatt Westinghouse four-loop pressurized water reactor and a General Electric turbine-generator. It is owned by the Ameren Corporation and operated by subsidiary Ameren Missouri. It is one of several Westinghouse reactors built to a design called Standard Nuclear Unit Power Plant System, or SNUPPS. The plant produces 1,279 electrical megawatts (MWe) of net power. It has run continuously for over 500 days between refuelings, one of 26 U.S. reactors to do so. History In 2001, Callaway set a plant record by producing 101.1 percent of its rated electrical output, ranking it among the world's top reactors, according to the Energy Information Administration. On November 19, 2005, its workers finished replacing all four steam generators in 63 days, 13 hours, a world record for a four-loop plant. In 2008, Callaway produced about 19 percent of Ameren Missouri's power. In 2014, the Nuclear Regulatory Commission tests found contaminated ground water near the site. The plant experienced three unplanned shutdowns during the last three quarters of 2020. On December 24, 2020, an electric fault on the non-safety main generator caused an extensive outage requiring the replacement of significant components. The components were replaced, inspected, and tested during subsequent months. According to NRC inspection reports, on August 2, 2021, the reactor was restarted. Two days later on August 4, 2021, the main turbine generator was synchronized with the electrical grid and on August 8, the plant reached rated thermal power. Proposed Unit 2 and cancellation On July 28, 2008, Ameren Missouri applied to the U.S. Nuclear Regulatory Commission (NRC) for a Combined Construction and Operating License (COL) to build a 1,600-MW Areva Evolutionary Power Reactor. "Given projections for a nearly 30 percent increase in demand for power in Missouri in the next two decades, we believe we will need to build a large generating plant to be on line in the 2018–2020 timeframe," wrote Thomas R. Voss, the company's president and chief executive officer. In April 2009, the proposal was cancelled. One stumbling block was a law that forbids utilities to charge customers for the interest accrued on a construction loan before a new plant produces electricity. The new nuclear reactor would have cost at least