Nuclear power in the United Kingdom generated 16.1% of the country's electricity in 2020. As of December 2025, the UK has nine operational nuclear reactors at four locations (eight advanced gas-cooled reactors (AGR) and one pressurised water reactor (PWR)), producing 5.9 GWe.
It also has nuclear reprocessing plants at Sellafield and the Tails Management Facility (TMF) operated by Urenco in Capenhurst.
The United Kingdom established the world's first civil nuclear programme, opening a nuclear power station, Calder Hall at Windscale, England, in 1956.