Power down

Power down

Repaired or not, the San Onofre nuclear plant remains a dangerous and expensive albatross around the neck of SCE

By John Grula 10/04/2012

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(sixth in an ongoing series on the performance of California utilities) 
 
At the risk of engaging in vast understatement, it has not been a good year for Southern California Edison (SCE), the investor-owned, for-profit utility that serves 14 million customers in Southern, Central and Coastal California. This year, SCE’s primary disaster involves its San Onofre nuclear power station, located about 70 miles southeast of Pasadena, near the coastal city of San Clemente.
 
San Onofre has been shut down since Jan. 31, when it was discovered radioactive steam was leaking from defective tubes carrying water in the plant’s brand new steam generators, which are key components for the production of electricity. The radioactive leaks were discovered to have been caused by excessive and totally unexpected wear to a large fraction of the 9,727 U-shaped tubes inside each steam generator. Not only are the radioactive leaks from the tubes a major concern, but more serious leaks could drain protective cooling water from a reactor; if this were to happen, San Onofre could experience a serious nuclear meltdown similar to the triple meltdown that occurred in March 2011 at the Fukushima nuclear power plant in Japan.
 
What’s causing the excessive tube wear? On July 19, the federal Nuclear Regulatory Commission (NRC) released a report that said Mitsubishi Heavy Industries, the firm that designed and manufactured San Onofre’s new steam generators, had employed faulty computer models, which failed to accurately predict conditions inside the new steam generators. Furthermore, manufacturing flaws in the tubes contributed to excessive vibration between tubes and within their support structures, and this has caused considerable tube damage. Some critics, such as US Sen. Barbara Boxer (D-Calif.), have questioned whether the new steam generator designs were adequately reviewed by the NRC and have also raised the possibility that SCE may not have fully informed the NRC about the new designs.
 
According to the Los Angeles Times, the NRC is still waiting for SCE to submit an analysis of San Onofre’s problems and a restart plan for one of the plant’s two reactors, Unit 2, by early October. After that, it will take at least several months for the NRC to review SCE’s analysis and plans. If or when Unit 2 will fire-up again is anybody’s guess. The second reactor, Unit 3, has even more tube damage than does Unit 2 and will probably require very extensive and costly repairs, so its restart date is even more uncertain. 
 
Which brings us to the economics of this whole fiasco. The cost of the new steam generators, installed less than two years ago, was $770 million, according to another report in the Times. If the generators need to be completely replaced, which seems likely, the price tag could be very similar. Who would foot the bill — SCE customers or the company’s shareholders? So far, the California Public Utilities Commission hasn’t made a decision about this. But, does it make economic sense to undertake highly expensive repairs on a plant whose operating license expires a mere 10 years from now? The fact that, in late August, SCE reduced its workforce at San Onofre from about 2,250 to 1,500 strongly suggests the company has already given up on making the needed repairs and restarting the twin reactors. 
This is music to the ears of anti-nuclear activists, who have repeatedly called for the permanent closure of San Onofre. However, even if unfavorable economics dooms the plant and it is never restarted, what kind of radioactive mess will it leave behind? 
 
Irvine City Councilman Larry Agran estimates that 4,000 tons of radioactive waste is stored at San Onofre, according to a report in the Orange County Register. This waste is comprised mainly of spent reactor fuel rods, which will continue generating massive amounts of heat for decades after they have been decommissioned. Because the radioactive rods are so physically hot, they are stored in temporary storage pools in which water is circulated to make sure the rods don’t overheat, which could cause their casings to catch fire and release radiation into the atmosphere. This was one of the primary causes of the massive radioactive emissions from Fukushima last year.  
 
In this regard, San Onofre is like every other nuclear power plant in our country. Because there is no permanent storage site for spent nuclear fuel in the US, many thousands of tons of it have been accumulating for decades at all of our nuclear plants. According to the Union of Concerned Scientists, most of the pools designed for temporary storage have been “re-racked” to allow up to five times as much spent fuel to be placed into storage than the pools were originally designed to hold. As most of the pools are outside the primary containment barriers meant to prevent radiation release, they’re more likely to release large amounts of radiation in the event of an accident, such as the one that occurred at Fukushima.
 
Whether or not San Onofre ever restarts, it will continue to be a colossal albatross around SCE’s neck. Even worse, it will remain a serious danger to the public for many years to come. 

John Grula, PhD, is affiliated with the Southern California Federation of Scientists.

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