 Nine of the reactors were designed by Allmänna Svenska Elektriska Aktiebolaget (ASEA), three supplied by Westinghouse.After the Three Mile Island accident in 1979, there was a national referendum in Sweden about the future of nuclear power.As a result of this, the Riksdag decided in 1980 that no further nuclear power plants should be built, and that a nuclear power phase-out should be completed by 2010.