San Onofre Nuclear Generating Station

Bret Bonanni
November 29, 2016

Submitted as coursework for PH240, Stanford University, Fall 2016

Background of the Station

Fig. 1: SONGS located in North San Diego County remains in close proximity to the Pacific Ocean as pictured above. (Source: Wikimedia Commons)

The San Onofre Nuclear Generating Station (SONGS) is located in the northwestern corner of San Diego County. As seen in Fig. 1, the station covers a large area of space which neighbors the Pacific Ocean. Owned and operated by Southern California Edison, San Diego Gas and Electric, and the city of Riverside; the facility occupies approximately 214 acres within the boundaries of the Camp Pendleton U.S. Marine base. SONGS was shut down permanently in 2013, thus ending the operation of the site after 45 years. The plant's first unit, Unit 1, saw operation from 1968 to 1992. Unit 1 was a pressured water reactor and has been a storage facility for spent fuel since its closure in 1992. Unit 2 began in 1983, while Unit 3 started in 1984. Both Unit 2 and 3 are combustion engineering two loop pressurized water reactors. Units 2 and 3 were shut down until further notice in January of 2012 due to premature wear found on over 3,000 tubes in replacement steam generators that had been installed in 2010 and 2011. [1] Due to the tremendous cost of repair to get the plant back into a safe working order, the Southern California Edison Company announced that they would be permanently closing down the plant in June of 2013. [2]

Potential Risk

In 2011, nearly six million people lived in the danger zone of the SONGS site. [3] Due to the growing density of the surrounding population, SONGS has become a hazardous concern for many. Though the retirement of the site was in 2013, the potential threat regarding the site still remains prevalent, as it has become a center of nuclear waste. Approximately 43 percent of the intermediate and long-lived radioactivity in the spent nuclear fuel at SONGS is Cs-137. [1] The reactors at San Onofre have generated about 210 million curies of Cs-137. [1] That being said, the two fuel pools located on the site contain roughly 168 million curies of Cs- 137. [1] As a frame of reference, this quantity of Cs-137 is more than 6 times the amount released by all atmospheric nuclear weapon tests, and about 89 times that which was released by the Chernobyl accident. [1] With SONGS being in an earthquake prone location, it is clear that any sort of large earthquake could cause damage to the pools thus leading to nuclear drainage that would cause catastrophic nuclear disaster, threatening the lives of many.

© Bret Bonanni. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.


[1] R. Alvarez, "Storage of Nuclear Waste From Spent Fuel at San Onofre," Friends of the Earth, 25 Jun 13.

[2] "Timeline of San Onofre Plant's Operations," San Diego Union-Tribune, 7 Jun 13.

[3] "San Diego County Demographics Profile," County of San Diego, March 2013.