TIMELINE: San Onofre Nuclear Generating Station

April 8, 2013: Fatigue damage will restrict Unit 2 steam generator from restarting. (Source: NRC.gov)

April 3, 2013: The operator of the San Onofre Nuclear Generating Station wants to put its reactor restart plan into effect on June 1. (Source: 10News.com)

March 25, 2013: Dr. Joram Hopenfeld, a former Nuclear Regulatory Commission employee, writes a testimony about the San Onofre Nuclear Generating Station tube failures. (Source: Dr. Joram Hopenfeld)

March 22, 2013: Southern California Edison announced it has a new proposal to restart Unit 2 at the San Onofre Nuclear Generating Station. (Source: 10News.com)



March 18, 2013: The utility, operator and majority owner of SONGS, said a technical evaluation by Intertek APTECH of Sunnyvale found that Unit 2 could operate at 100 percent with full integrity of steam generator tubes. (Source: 10News.com)

March 16, 2013: Seven tubes in total have failed a pressure test. (Source: 10News.com)

Feb. 28, 2013: San Diego's former city attorney, Michael Aguirre, asks the California Public Utilities Commission to return ratepayer money because San Onofre Nuclear Generating Station was using substandard equipment. (Source: 10News.com)

Feb. 6, 2013: Senator Barbara Boxer sent a letter to immediately investigate new information that indicates Southern California Edisonand Mitsubishi Heavy Industries may have been aware of problems with the design of the San Onofre nuclear power plant’s replacement steam generators before they were installed. (Source: State Senator Barbara Boxer)

Jan. 23, 2013: The San Diego Unified School District Board of Education on Tuesday adopted a resolution opposing the proposed restart of a reactor until its operator undergoes a rigorous license amendment process. (Source: 10News.com)

Sept. 1, 2013: An ammonia leak in a water-treatment system at San Onofre Nuclear Generating Station prompted an alert and partial evacuation at the facility. (Source: 10News.com)

Sept. 30, 2012: Southern California Edison found coolant in a backup generator's oil. (Source: 10News.com)

Nov. 8, 2012: Friends of the Earth argues that Southern California Edison did not get a proper license amendment when the steam generators for Units 2 and 3 were replaced in 2010 and 2011. (Source: NRC.org/Friends of Earth memo)



Nov. 2, 2012: Since the closure of Units 2 and 3, the estimated costs are $300 million. (Source: 10News.com)

Oct. 22, 2012: A minor hydrogen leak was detected, but not reported harmful. (Source: 10News.com)

Oct. 3, 2012: Southern California Edison proposes to operate Unit 2 at no more than 70 percent power without exceeding 150 days before conducting the next set of inspections of that unit's steam generator tubes. (Source: NRC.gov)

Sept. 30 2012: In filings with the U.S. Securities and Exchange Commission, the companies reported having spent $774 million. (Source: Los Angeles Times)

Sept. 28, 2012: The Nuclear Regulatory Commission begins expansive investigation on the accuracy of oversight of the redesign on the new generators.  (Source: U.S. NRC blog)

August 27, 2012: The operator of the San Onofre nuclear power plant prepares to empty the radioactive fuel from Unit 3. (Source: Huffington Post)

March 27 2012: The Nuclear Regulatory Commission issued a Confirmatory Action letter documenting actions that Southern California Edison officials have agreed upon to seeking permission to restart the reactors. (Source: NRC press release)

March 19, 2012: The Nuclear Regulatory Commission initiated an Augmented Inspection Team to assess the tube leak and unexpected wear of tubes in the Unit 3 Steam Generators. (Source: NRC.gov)

Jan. 31, 2012: Control room operators received alarms indicating that reactor coolant was leaking into one of the steam generators from Unit 3. (Source: NRC.gov)

Jan. 27, 2012: Worker falls into primary coolant pool trying to reach his flashlight. (Source: Los Angeles Times)

Jan. 2012: Unit 2 and 3 reactors at San Onofre have been shut since January 2012 because of premature wear found on tubes inside the steam generator. (Source: Los Angeles Times)

Jan. 2010 & 2011: San Onofre replaced the Unit 2 steam generators in 2010 and Unit 3 2011. Each replacement generator was manufactured by Mitsubishi Heavy Industries. (Source: NRC.gov)

February 2005: San Diego Gas & Electric opposes the replacement of the steam generators because it’s too expensive of a project. San Diego Gas & Electric said it would have to ask its 1.2 million customers for $163 million to pay its share. (Source: California Public Utilities)

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