Segment I Nuclear Power In the Valley? - The State of California has a long love-hate relationship with nuclear power. It's now been 26 years since Diablo Canyon, the state's newest nuclear power plant, came online on the Central Coast. In the intervening years, reactors at Rancho Seco, near Sacramento, and San Onofre near San Diego have been decommissioned, and the state's moratorium on the construction of new plants still remains in effect.