Edison International, parent of SCE, holds 78.2% ownership in the plant; San Diego Gas & Electric, 20%; and the City of Riverside Utilities Department, 1.8%.

"[9] Controversy continues over Edison's plans for on-site dry cask storage of the considerable amount of nuclear waste created during the facility's decades of operation.

[10][11] Unit 1, a first-generation Westinghouse pressurized water reactor that operated for 25 years, closed permanently in 1992; it has been dismantled and is used as a storage site for spent fuel.

The NRC issued a license amendment in February 2010 releasing the off-shore portions of the Unit 1 cooling intake and outlet pipes in place, under the Pacific Ocean seabed, for unrestricted use.

[18] In 2008, the San Onofre plant received multiple citations over issues such as failed emergency generators, improperly wired batteries and falsified fire safety data.

[24] Southern California Edison stated after the Fukushima disaster in 2011 that the station was "built to withstand a 7.0 magnitude earthquake directly under the plant".

[27] The NRC's estimate of the yearly risk of an earthquake intense enough to cause core damage to the reactor at San Onofre was 1 in 58,824, according to a study it had published in August 2010.

[28][29] In June 2012 S. David Freeman, the former head of the Southern California Public Power Authority and "a longtime anti-nuclear voice",[30] described San Onofre and Diablo Canyon as "disasters waiting to happen: aging, unreliable reactors sitting near earthquake fault zones on the fragile Pacific Coast, with millions of Californians living nearby".

[41] In May 2012, environmental and anti-nuclear activists gathered at Southern California Edison's Irvine headquarters calling for the San Onofre plant to be decommissioned.

[48] On January 31, 2012, Unit 3 suffered a radioactive leak largely inside the containment shell, with a release to the environment below allowable limits, and the reactor was shut down per standard procedure.

There were no blackouts due to the lack of SONGS electricity; more pollution was caused by the use of natural gas plants to make up for the lost power generation, and additional cost led to higher utility bills.

[33] Concerns included "nuclear waste stored at the plant, health hazards from radioactive material, and inadequate evacuation plans".

Resolutions passed in neighboring cities Laguna Beach and San Clemente called for safer and more secure nuclear waste storage.

Friends of the Earth submitted evidence and sworn statements of John Large of the London-based nuclear consulting engineers Large & Associates, demonstrating that the steam generating tube degradation was a generic fault of the Mitsubishi design and that Edison's power derating of the two nuclear units would not lower the rate of wear or the risk of catastrophic tube failure.

[59] The Chairman of Edison International Ted Craver stated the possibility that reactor 3 might be scrapped as "It is not clear at this time whether Unit 3 will be able to restart without extensive additional repairs".

[55][62] SCE reported that most of the excessive wear had been in limited areas, due to higher speed and drier steam than computer modeling had predicted, and inadequate tube support at the U-bend.

[72][73] It determined the current NRC process on this issue constituted a de facto license amendment requiring an adjudicatory public hearing, for three independent reasons:[55] In May 2013, Senator Barbara Boxer asked that the United States Justice Department investigate possible malfeasance by Edison officials, and released a 2004 letter by an Edison executive that expressed worries that the new steam generators, though similar, would not be "like for like" replacements and could lead to the same kind of potential "disastrous" issues that in fact led to the plant's shutdown in 2012.

[77] California Senator Dianne Feinstein signaled approval of the decision to permanently close the plant, stating "I firmly believe this is the right thing to do for the more than 7 million Californians who live within 50 miles of San Onofre."

However, Representative Darrell Issa, whose voting district includes the nuclear station, was more downbeat, saying "our communities now face the loss of employment for more than a thousand highly skilled workers and an essential local source of low-cost, clean energy."

In contrast, Sierra Club Director Kathryn Phillips applauded the move, saying in a statement that "We hope, especially, that the utilities will take this opportunity to help get more locally generated renewable energy, such as rooftop solar, into their portfolios.

"[78] In 2015, State Attorney General Kamala Harris opened an investigation of the Office of Ratepayer Advocates, San Diego Gas and Electric, and Southern California Edison.

California state investigators searched the home of California utility regulator Michael Peevey and found hand written notes, which showed that Peevey had met with an Edison executive in Poland, where the two had negotiated the terms of the San Onofre settlement leaving San Diego taxpayers with a $3.3 billion bill to pay for the closure of the plant.

[82] In August 2014, SCE announced decommissioning would take 20 years, cost $4.4 billion and spent fuel would be held on-site in dry casks indefinitely, while Low Level Radioactive Waste would be disposed in Texas and Utah.

These steel-lined concrete monoliths right next to the Pacific Ocean exceed California's earthquake requirements and Edison says they are designed to withstand fire and tsunamis.

In April 2017 Southern California Edison agreed to move spent nuclear fuel off the site, following legal action by San Diego environmental group Citizens Oversight.

[91] In March 2017 the International Chamber of Commerce ordered MHI to pay $125 million compensation, the liability limit contained in the contract.

[92] The tribunal rejected claims of fraud and gross negligence against Mitsubishi, and ordered the claimants to pay MHI $58 million in legal fees and costs.

The San Onofre Nuclear Generating Station is shown in the 1987 film Made in U.S.A. directed by Ken Friedman and starring Adrian Pasdar, Chris Penn and Lori Singer.

SONGS was also featured in Godfrey Reggio's 1982 experimental film Koyaanisqatsi, where sunbathers are shown on San Onofre State Beach in front of the station.

[93] Passing reference is made to the design of the containment shields (which resemble breasts) in the lyrics of the Descendents song "Kids" from their 1986 album Enjoy!, and in the cult comedy The Naked Gun (1988).