The plant operator, British Energy, has suggested that the site would be a suitable location for a further nuclear power station. This is opposed by environmental groups such as Greenpeace.
Construction of Heysham 1 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 likely to remain in operation until 2014. Its generating capacity is 1150 MWe.
Heysham 1 shares its reactor design with Hartlepool 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 lesson was learned and the Heysham 2 reactor island occupies a much larger footprint than Heysham 1 for a similar design output of power.
Construction of Heysham 2 began in 1979, and the station opened in 1988. Its generating capacity is 1250 MWe, and it is estimated to keep running until at least 2023. Heysham 2 shares its reactor design with Torness nuclear power station and is a development of the reactor design used at Hinkley Point B.