Rancho Seco Nuclear Generating Station

The Rancho Seco Nuclear Generating Station is a decommissioned nuclear power plant built by the Sacramento Municipal Utility District (SMUD) in Herald, California. In 1966, SMUD purchased 2,100 acres in southeast Sacramento County for a nuclear power plant, which was built in Herald, 25 miles south-east of downtown Sacramento. The reactor entered commercial operation April 17, 1975. On March 20, 1978 a power failure of the plant's non-nuclear instrumentation system led to steam generator dry out. In an ongoing study of "precursors" that could lead to a nuclear disaster if additional failures were to have occurred, the United States Nuclear Regulatory Commission concluded that this event at Rancho Seco was the third most serious safety-related occurrence in the United States (Behind the Three Mile Island accident and the cable tray fire at Browns Ferry). The plant operated from April 1975 to June 1989; it was closed by public vote June 7, 1989. All power generating equipment has been removed from the plant and the now-empty cooling towers remain a prominent part of the local landscape. Also scattered throughout the area around the plant are abandoned air raid sirens that at one time would have warned people of a radiation release from the station. On Oct. 23, 2009, the Nuclear Regulatory Commission released the majority of the site for unrestricted public use; while approximately 11 acres of land including a storage building for low-level radioactive waste and a dry-cask spent fuel storage facility remain under NRC licenses.