San Onofre Nuclear Power Plant, California

The San Onofre Nuclear Generating Station (SONGS), between Los Angeles and San Diego, is one of two nuclear power plants directly on the west coast of the United States (the other is the Diablo Canyon Nuclear Power Plant, in Central California), and is now permanently closed.  San Onofre is on a narrow strip of land between Interstate 5 and a popular surfing beach. The plant is home to three pressurized water reactors, and is owned by Southern California Edison Company. Unit 1 was in operation from 1968 until 1992, with a net output capacity of 436MW. Unit 2 was in operation from 1983 until 2013, with a net output capacity of 1070MW. Unit 3 was in operation from 1994 until 2013, with a net output capacity of 1080MW. In 2012, Southern California Edison discovered that a design flaw had caused extensive damage to critical components of the reactor's steam generators, which had led to radiation leaks. In 2013, Southern California Edison decided to permanently close Units 2 and 3, as the cost of repairing and restarting the reactors would have been prohibitive.  Spent fuel from all three reactors will remain on site in an Independent Spent Fuel Storage Installation (ISFSI). Rather than employ the more common aboveground dry cask storage system, Southern California Edison has instead chosen a Holtec-designed system in which the casks are stored in underground concrete vaults.