San Onofre

There were shock waves across Southern California on June 7, 2013 from the San Onofre Nuclear Generating Station. They didn’t originate at earthquake faults adjacent to this nuclear plant, located above the Pacific Ocean. Rather, they emanated from the facility’s primary owner and operator, Southern California Edison. The heavyweight utility announced that it was giving up its fight to restart San Onofre, and was permanently shutting it down.

Actually the nuke plant’s two operating reactors had already been shut down since January 2012. Edison’s decision can be traced to its pattern of extreme mismanagement of plant operations, consequent huge financial losses and the tenacious opposition that rallied local communities.

San Onofre is the largest nuclear power plant to be shut down in the U.S. One reactor was retired in 1992. The other two, just cut loose, had formerly generated 2200 Megawatts of electricity to 1.5 million households. Located between San Diego and Los Angeles, the plant supplied power to 1.5 million households—8.7 million people live within 50 miles of it. The two reactors at San Onofre had been scheduled to operate until 2022.

In the Shadow of Fukushima

The 2011 nuclear disaster at Fukushima created heightened awareness of the possibility of similar problems at U.S. nuclear plants. California’s Diablo Canyon and San Onofre nukes, like Fukushima, were aging reactors located on coastlines subject to earthquakes and tsunamis. Radioactive clouds from Fukushima reached the West Coast within a week of its meltdowns, and hot stuff came down in rains before continuing across North America. Subsequent studies by the Radiation and Public Health Project ( indicated a spike in mortality nationally after the radioactive clouds passed, most acutely in infant deaths.

The effects of a nuclear meltdown were no longer theoretical. It had happened here. Long before Fukushima, San Onofre had already been having its own problems. Reactor Unit 1, started up in 1968, had to be shut down in 1992 after problems with the equipment. In 2006, workers found radioactive water under Unit 1 that was 16 times more radioactive than EPA- permitted levels for its presence in drinking water. And this was 14 years after that reactor had been shut down.

In August 2008, the Los Angeles Times reported, “Injury rates at San Onofre put it dead last among U.S. nuclear plants when it comes to industrial safety.” Later that year, it emerged that a battery system, key to providing backup power to pump water to flood Unit 2’s reactor in case of a potential meltdown, “was inoperable between 2004 and 2008 because of a loose electrical connection,” the Nuclear Regulatory Commission reported.

Also in 2008, the Radiation and Public Health Project reported in the European Journal of Cancer Care, that the counties nearest San Onofre had the highest child leukemia mortality rates of counties near nuclear power plants studied for the years 1974-2004.

Shut Down

In 2009 and 2010, Edison found it necessary to replace the four massive steam generators in San Onofre’s units 2 and 3. The original steam generators lasted over a quarter century, though they were supposed to last for the life of the reactors—40 years.

Steam generators facilitate the creation of steam to turn turbines to generate electricity, in the type of nuclear plants most common in the U.S. Water pipes run through reactors and are heated by nuclear fuel. But this water also picks up lots of radioactivity. The steam generators have tubes that pass on the heat to another set of pipes that make the steam while not passing on the radioactivity, which otherwise would escape into the environment and contaminate it. Thus, the steam generators are key to keeping these nuclear plants running safely.

Edison reportedly spent $680 million on replacement steam generators. Since the plant was not originally designed to need replacements, the utility had to cut huge holes in buildings to get them inside. And then they turned to junk in just a few years.

In a March 2012 report, Arne Grundersen, of Vermont’s Fairewind’s Associates, a former nuclear industry engineer, described the decisive moments of San Onofre’s shut down in January 2012: “Unit 3 was operating at full power and experienced a complete perforation of one [steam generator] tube that allowed highly radioactive water from inside the reactor to mix with non-radioactive water that was turning the turbine. As a consequence, an uncontrolled release of radiation ensued, and San Onofre was forced to shut down due to steam generator failure.”

Subsequent investigations of the steam generators revealed that over 3,000 tubes in both units were showing signs of premature wear. In July 2012, the Los Angeles Times put the number of deteriorated tubes at 3,401.

Neither Edison nor the NRC could pinpoint the cause of the tubes rapid degradation. Yet Edison continued to press for early restart and the NRC wasn’t automatically denying the utility that opportunity. But the utility’s projected date for restart was pushed back.

As the total shutdown at San Onofre dragged on through the spring and summer of 2012, Edison’s finances began hemorrhaging badly. It had to spend millions on work at the nuclear plant and millions more to buy replacement power for its customers. Even though Edison’s ratepayers weren’t getting anything but bills from San Onofre, the utility kept on charging them for the plant’s ever increasing costs.

During all this time, there were no brownouts or blackouts in Southern California. People were starting to realize they could get along just fine without San Onofre.

Information then began to surface as to possible causes of the steam generator debacle. There had been design changes in the replacement steam generators by Edison’s contractor, Mitsubishi Heavy Industries. These had caused vibrations inside the new steam generators, which resulted in decades-early wear and tear.

The Associated Press reported on July 19, 2012, that Edison admitted the replacement steam generators “each weighed 24 tons more than the original ones” and added 400 tubes to each one. 

Edison was supposed to have notified the NRC of changes in the design of the replacement steam generators. But it didn’t, because that would have necessitated more scrutiny from the NRC and cost the utility more time and money.

That issue went viral in early February 2013, when Senator Barbara Boxer of California and House Representative Ed Markey of Massachusetts went public with a letter to NRC Chief Alison Macfarlane. The letter read, in part: “Southern California Edison, and Mitsubishi Heavy Industries were aware of a series of problems with the design of San Onofre nuclear plant’s replacement steam generators before they were installed. Further, SCE and MHI rejected enhanced safety modification and avoided triggering a more rigorous license amendment and safety review process.”

Boxer and Markey cited a 2012 MHI report as their source of this information, but refused to make the report available to the public.

Just Saying No To Nukes

As Edison continued to push for restart at San Onofre while revelations of its duplicity continued to surface, people started to take action to keep themselves safe. Opponents of restart marched on the nuclear plant to express their displeasure with Edison’s disregard for their safety in its mismanagement there. They voiced their concerns about Edison putting “profit before people” in its response to the crisis at San Onofre.

They went to local school boards and other municipal bodies, persuading them to ask the NRC to delay giving Edison permission to restart San Onofre until it could guarantee its safe operation.

Perhaps most notably in this respect, the Los Angeles City Council voted 11-0 in late April to make such a request. That action came not long after Edison proposed restarting Unit 2 in June, at 70 percent power. This “experimental” startup would have lasted two years, during which time the reactor would likely have shut down a number of times.

In response to that move, the environmental group Friends of the Earth, which had been actively opposing the utility’s unprincipled actions, issued a report in which it asserted that if the NRC granted Edison’s request, “the unrepaired tubes will vibrate, suffer further wear and potentially burst in 6-13 months.”

Also in the report, the group quoted renowned nuclear engineer John Lodge, who stated, “Edison has yet to provide convincing evidence that it knows the full reasons or root cause of the severe damage to its steam generators. The problems remain unresolved and unrepaired.”

Subsequently the NRC granted Friends of the Earth’s request for the “more vigorous license amendment and safety review process” Boxer and Markey had referred to, exactly what Edison had been trying to evade all along. As it turned out, June brought forth, instead of the restart Edison so desperately wanted, San Onofre’s complete and irrevocable shutdown.


Michael Steinberg is a veteran activist and the author of Millstone and Me: Sex, Lies and Radiation in Southeastern Connecticut.