There are five nuclear power plants operating in Spain, of which Almaraz and Ascó have two twin units so that there are seven operational reactors. There is also one plant in the definitive shutdown situation, Santa María de Garoña.

These seven electricity production units are divided into two types, those using pressurised light water (PWR) and those using boiling light water (BWR). In chronological order, the list of plants in the BWR group is Almaraz, with two units (1980 and 1983); Ascó, also with two units (1982 and 1985); Vandellós II (1987) and Trillo, the last power plant put into operation in Spain (1987).

In the group of boiling water (BWR) power plants, the oldest is Santa María de Garoña (1970) followed by Cofrentes (1984).