The 1970s proved a pivotal period in California's history with nuclear power. The climate between nuclear power advocates and environmentalists was confrontational. While voters failed to pass a 1972 proposal placing a 5-year moratorium on nuclear plant construction, conservation and environmental groups worked throughout the decade to stop construction of several proposed plants, especially along the coast and near fault lines.

In 1975, Jerry Brown replaced Ronald Reagan as California's governor, and the California Committee for Nuclear Safeguards qualified Proposition 15 for the state ballot. This stringent proposition, which ultimately failed at the polls, would have prohibited licenses for any new power plants until public 'proof' of an effective radioactive waste disposal system was discovered.

In 1976, just before this measure failed at the polls, Governor Brown passed three nuclear safeguard laws; one of which included the provision that the Resources Conservation and Development Commission of California and the Legislature determine at lease one method of disposing of radioactive waste material safely. Most utilities supported the laws in an attempt to ward off Proposition 15.

In 1972, San Diego Gas & Electric (SDG&E) began planning a new nuclear energy facility for southern California. In 1975, the year before California's new safeguard laws were enacted, they purchased land for the plant, approximately 16 miles southwest of Blythe and 10 miles from the Colorado River. On February 17, 1976, SDG&E filed a notice of intent with the state's Resources Conservation and Development Commission to build the Sundesert Nuclear Plant (SNP). The proposal was the first submitted to California's new "one step" approval system, implemented in 1974.

SNP would provide electric power to customers within the service areas of SDG&E, who held a 50% interest in the project. The California Department of Water Resources, Los Angeles Department of Water and Power, the cities of Anaheim, Glendale, Pasadena, and Riverside also held interest in the project. The proposed plant would consist of two 950-megawatt nuclear generators, the first scheduled to go into service in 1985, and the second in 1988.

The need for the plant was almost immediately disputed, as well as its negative environmental impact, as its proposed creation encountered resistance from citizens, local governments, and state-wide government agencies. Several environmental issues were raised, in addition to the problem of nuclear waste disposal, including the presence of nearby fault lines.

While the state's Legislative Counsel argued that California's new nuclear safeguard laws unconstitutionally infringed upon the federal government's regulation of nuclear plant hazards, the SNP sought out legislative immunity to the new regulations. In mid-1977 Assemblyman Alister McAlister authored a bill that would potentially exempt SNP from California's 'de facto' ban on new atomic factory construction.

In December the state Resources Conservation and Development Commission, who's members had all been appointed by Governor Brown, gave preliminary approval to the proposed $3 billion Sundesert project, but cut the plant's size in half and saddled it with numerous restrictions. The following month the same commission released a report that concluded all nuclear power plants were not safe because of their inability to dispose of radioactive waste. They urged the state legislature not to exempt SNP from the safeguard laws not because of any particular flaw or problem in the proposal, but because of waste disposal problems inherent to any and all nuclear energy facilities.

In January 1978, the California Senate voted 21 to 10 to exempt SNP from the state's nuclear safety laws, but the Democrat-controlled Assembly committee ultimately rejected the exemption due to persistent concerns regarding the potential dangers in storing nuclear waste. This decision marked the end of the Sundesert Nuclear Power project and was seen as a major turning point in the state's energy policy.

In 1983, the U.S. Supreme Court heard arguments regarding California's moratorium on new nuclear plant construction; Pacific Gas & Electric v. State Energy Resources Conservation & Development Commission. This was a direct challenge to the 1976 statue that prohibited construction of new nuclear plants in the state until adequate storage facilities and means of disposal for nuclear waste were determined.

Two California utilities and the federal government argued that the Atomic Energy Act gives the United States Nuclear Regulatory Commission sole authority to regulate nuclear power plant construction and operation. Interestingly, the Court sided with the state of California based on economic and land use issues, rather then on protection from radiological hazards, stating that while the federal government oversees health and safety matters, the states may regulate nuclear power on an economic basis.