While Californian voters failed to pass a 1972 proposal placing a 5-year moratorium on nuclear plant construction , anti-nuclear groups campaigned to stop construction of several proposed plants in the seventies , especially those located on the coast and near fault lines . While Californian voters did not pass a 1972 proposal placing a 5-year moratorium on nuclear plant construction , anti-nuclear groups campaigned to stop construction of several proposed plants in the seventies , especially those located on the coast and near fault lines .