Construction of Heysham 1, which was undertaken by British Nuclear Design & Construction (BNDC), a consortium backed of
English Electric,
Babcock & Wilcox and
Taylor Woodrow Construction, began in 1970, with the first reactor commencing operations in 1983 and the second reactor following in 1984. However, initial production levels were low, and full commercial operation was only declared in 1989. It is planned to remain in operation until 2028. Its generating capacity is 1,150MWe. The reactors were supplied by National Nuclear Corporation and the turbines by
GEC. There were four 17.5MW auxiliary gas turbines on the site, these had been first commissioned in January 1977. Heysham 1 shares its reactor design with
Hartlepool nuclear power station, which introduced the replaceable pod boiler design. The
CEGB specified a compact design for the Heysham 1 and Hartlepool power station reactor islands in comparison to the design of the two preceding stations at
Hinkley Point B and
Hunterston B in order to reduce the capital cost, but this caused expensive construction delays because of restricted access. The Heysham 2 reactor island occupies a much larger footprint than Heysham 1 for a similar design output of power. In 2013, a defect was found by a regular inspection in one of the eight pod boilers of unit 1. The reactor resumed operation at a lower output level with the defective pod boiler disabled, until June 2014 when more detailed inspections confirmed a crack in the boiler spine. As a precaution, unit 2 and the sister
Hartlepool nuclear power station were also shut down for inspection. Heysham 1 was scheduled to be shut down for defueling and then decommissioning in March 2024. EDF subsequently announced plans to extend the life of Heysham 1 and Hartlepool to March 2026. In December 2024, EDF further extended the life of Heysham 1 until March 2027. In September 2025, following an inspection of the graphite cores, EDF announced a further one year extension to March 2028. ==Heysham 2==