The DCPP is an electricity-generating nuclear power plant located near the community of Avila Beach in San Luis Obispo County, California. After the permanent shutdown of the San Onofre Nuclear Generating Station in 2013, it is the only remaining operational nuclear power plant in the state.

The facility, which is located on about 700 acres of which about 12 acres form the power-producing portion of the plant, has been in operation since 1985.  Its two Westinghouse Pressurized Water Reactor units are licensed until 2024 and 2025 respectively.  The two units produce a total of 18,000 gigawatt-hours of electricity annually, which is enough energy to meet the needs of more than three million Northern and Central Californians.  This is nearly 10 percent of California’s energy portfolio and 20 percent of the power that PG&E provides throughout its service area.

In February, 1963 PG&E announced plans to construct five nuclear reactors at the Nipomo Dunes in southern San Luis Obispo County.  Protests were immediately raised and later that year, the Sierra Club met with PG&E to discuss establishing the new power plant on an alternative site. PG&E agreed to choose an alternative site and two years later in 1965, the Diablo Canyon site became the new alternative to the Nipomo Dunes.  Over the next three years, PG&E began the process for construction of a two unit reactor with the Atomic Energy Commission (precursor to the Nuclear Regulatory Commission) and the California Public Utility Commission (CPUC).  The Atomic Energy Commission formally approved the construction permit in April 1968 and in July of 1968, construction began on Unit 1.  The Unit 2 construction permit was issued in December of 1970, with construction beginning in early 1971.

Continuing through the 1970s, there were hearings, referenda and litigation covering issues involving earthquake safety, security plans, and environmental quality.  In 1984, after 14 years of hearings, protests, blockades, interventions, court cases, retrofits and reconstruction, PG&E was granted a full power licenses by the Nuclear Regulatory Commission (NRC) for Unit 1 on August 2nd and Unit 2 on November 2nd.  On May 7, 1985, Unit 1 began commercial operation and on March 13, 1987, Unit 2 followed.

In June 2016, PG&E announced plans to close the two Diablo Canyon reactors in 2024 and 2025. This resource planning decision was approved by the CPUC on January 11, 2018 (Decision 18-01-022).  In February 2018, PG&E withdrew its application to the NRC for a licensing extension.