January 1, 1968: Operations began at San Onofre Unit 1 reactor, a Westinghouse 3-loop pressurized water reactor.

May 3, 1976: The Nuclear Regulatory Commission began its Seismic Evaluation Program of operating reactors and found that Unit 1 was not built to federal standards.

April, 1980: Southern California Edison submits documents to the NRC arguing that Unit 1 is safe to operate, in spite of the fact that it does not meet federal seismic safety standards.

February 16, 1982: An Operating License is issued for San Onofre Unit 2, a Combustion Engineering 2-loop pressurized water reactor.

February 26, 1982: Unit 1 was shut down for refueling, as well as discussions between Edison and the NRC regarding the noncompliance of the reactor with federal seismic standards.

August 11, 1982: The NRC issues a Confirmatory Order requiring seismic retrofits for Unit 1 to be completed before the reactor is brought back online.

November 15, 1982: An Operating License is issued for San Onofre Unit 3, an identical twin of Unit 2.

November 28, 1984: After an extensive 2.8-year outage, the NRC allows Unit 1 to restart without the all seismic retrofits completed.

November 30, 1986: The deadline for the final seismic upgrades to Unit 1 passes, more than two years after the reactor was allowed to restart without the federally-mandated seismic safety retrofits completed.

November 30, 1992: Unit 1 is permanently shut down after Edison is faced with the exorbitantly high costs for more repairs, including to damaged steam generators.

November 3, 1994: Edison submits a decommissioning plan for Unit 1 to the NRC. This includes expanding the Independent Spent Fuel Storage Installation (ISFSI) to accommodate the large amount of highly-radioactive waste from Units 2 and 3, so this dangerous waste can continue to accumulate and be stored in non-permanent storage onsite.

June 2006: Edison informs the NRC of its intention to replace the 28-year-old original steam generators in Units 2 and 3. The utility presents the replacement components as “like-for-like” replacements. This allowed them to go through a perfunctory review process, rather than an extensive critical safety review of the new equipment design. In fact, the proposed designs for the replacement equipment contained major design changes that should have required a license amendment and critical rigorous review.

November 2008: Failing to recognize the significance of the major design changes, the NRC completes its superficial review process and approves the replacement steam generators for Unit 2.

July 2009: Again failing to recognize the drastic design changes, such as the removal of critical stabilizing features and the addition of 377 more tubes to the replacements, the NRC completes the perfunctory review and approves the replacement steam generators for Unit 3.

2009 and 2010: The replacement steam generators are installed in both reactors.

May 2010: Reactor Unit 2 is returned to power with the replacement steam generators installed.

February 2011: Reactor Unit 3 is returned to power with the replacement steam generators installed.

August 11, 2011: The NRC issues the Near Term Task Force report on lessons learned from Fukushima. This includes seismic safety considerations, among other issues, which apply to the San Onofre reactors.

January 9, 2012: The Unit 2 reactor is shut down for a scheduled refueling.

January 31, 2012: A radioactive leak from a tube failure in one of the steam generators in Unit 3 forces the emergency shut down of the reactor. Initially, Edison tells citizens that no radiation was released to the environment. This later is proven to be patently false. Further inspections reveal thousands of tubes showing wear in the four steam generators in both San Onofre reactors. Both reactors are kept offline for further analysis.

March 13-20, 2012: In-situ pressure testing is conducted on the steam generator tubes in reactor Unit 3. Eight tubes fail this testing. This is the first time in the history of the U.S. nuclear industry that more than one tube has ever failed such testing. This is also the first time that any tube constructed with the tube alloy in the replacement San Onofre steam generators – a strong nickel alloy called INCONEL 690 – has ever failed such testing. The in-situ pressure testing failures and the pervasive accelerated wear in thousands of other tubes indicates severe and unprecedented problems.

March 16, 2012: The NRC issues an Augmented Inspection Team charter, which creates a special task force to examine the problems at San Onofre.

March 27, 2012: The NRC issues a Confirmatory Action Letter to Southern California Edison, which outlines specific actions the utility must take in order for the agency to consider allowing restart of Units 2 and 3.

June 18, 2012: Friends of the Earth files a petition with the NRC requesting an emergency stay on restart and a license amendment with an adjudicatory public hearing prior to restarting the either reactor.

July 18, 2012: The AIT issues its final analysis of the problems. The report reveals violations of the NRC code under which the replacements were approved. It also reveals pervasive damage and the fact that these significant safety issues were revealed in a leak – and not a full-blown tube rupture – was lucky. It stated that a tube rupture – which can create a catastrophic cascading tube rupture accident and release a massive amount of radiation into the environment – could have been the first indication of the problems. The root cause(s) of the problems and a method for fixing them have not been determined. However, the the AIT does state that the problems in the steam generators of both units are the result of the same causal factors.

July 24, 2012: Friends of the Earth files a Freedom of Information Act request for all communications between Edison and the NRC, as well as between Mitsubishi – the company that fabricated the replacements – and the NRC. 

September 12, 2012: Edison officials announces at a Senate Environment and Public Works Committee hearing that they plan to submit a response to the Confirmatory Action Letter the first week of October.

Currently: Both San Onofre reactors remain offline. Southern California made it through the summer without a single watt of electricity from the crippled San Onofre nukes – with no blackouts or brownouts as a result of their shutdown.

Friends of the Earth is intervening in the Long-term Procurement Proceeding before the California Public Utilities Commission to argue that the energy from San Onofre nuclear reactors can and should be replaced with energy efficiency programs, renewables, and storage. These investments will be of greater benefit to ratepayers than continuing to sink money into aging, crippled, and dangerous nuclear reactors that are an unreliable source of energy. Even if these reactors were brought back online now – a dangerous gamble with critically-flawed equipment installed – they will face extended outages for seismic retrofits, much like Unit 1 was in the 1980's, for Once-Through Cooling retrofits to comply with California state law, and other recommendations from the NRC Near Term Task Force.