San Onofre Nuclear Generating Station (SONGS) 
Investigation into Closure 



On October 25, 2012 the CPUC opened an investigation into the causes and accountability for the outages at the San Onofre Nuclear Generating Station (SONGS). The decision sets a preliminary schedule that allows 18 months for the resolution of the investigation.

SONGS is a nuclear power plant owned (78.21%) and operated by Southern California Edison (Edison) serving customers in the greater Los Angeles area including Inyo, Kern, Kings, Mono, Orange, Santa Barbara, Tulare, Ventura, and San Bernardino counties.  It is co-owned with SDG&E (20%) and the City of Riverside (1.79%). 

On January 9, 2012, Unit 2 of SONGS was shut down for scheduled maintenance. On January 31, 2012, Edison also shut down SONGS Unit 3 due to a steam generator tube leak. Neither SONGS units ever came back online. 


Settlement Agreement

In April 2014, Public Advocates Office (the Office), Edison, SDG&E, and TURN, filed a comprehensive Settlement agreement with the CPUC that would prevent the utilities from recovering the cost of the SONGS defective replacement steam generators from ratepayers. The estimated benefit to ratepayers on a present value basis, compared with the utilities’ $4.7 billion original request, is $1.12 billion for Edison customers and $286 million for SDG&E customers.


Phase 1

Nature and effects of the steam generator failures in order to assess the reasonableness of utility actions and expenses, and whether customer refunds are required. 


Phase 2

Adjustments to Edison’s rate base and revenue requirement. 


Phase 3

Causes of damage, allocation of responsibility, reasonableness of repair actions.  


Phase 4

Adjustment to Edison’s 2013 revenue requirement.


On July 18, 2013, Edison served a formal Notice of Dispute on Mitsubishi Heavy Industries, which seeks to hold Mitsubishi accountable for design and manufacture defects in the SONGS' Replacement Steam Generators.  




See the proceeding docket.

See the Office's August 13, 2012 letter to CPUC commissioners urging them to remove SONGS from rate base until it comes back online.

See the Office’s August 1, 2012 joint stakeholder letter to CPUC commissioners urging them to open an investigation into the SONGS outage. The Office co-signed this letter with TURN, Center for Energy Efficiency and Renewable Technologies, Friends of the Earth, and the Alliance for Nuclear Responsibility.

Edison Filings and Testimony.

U.S. Nuclear Regulatory Commission SONGS webpage.