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| "Oh no, it wasn't the airplanes. It was beauty killed the beast." |
Via Ace Hoffman's Nuclear Failures Reports
The glitter of gold attracted the operators of the San Onofre Nuclear Generating Station. It did them in.
Faced with the need to upgrade an old design, SoCal Edison demanded of Mitsubishi (the contractor for the replacement steam generators) too many impossible and conflicting constraints.
Most Pressurized Water Reactors (PWRs) have three or four steam generators which, as the name implies, convert water to steam. San Onofre's reactors have only two steam generators each, so if one fails, the other has to handle the full task of cooling the reactor. This was one of many design flaws, but they had lived with it. The problem came when they tried to get even more output from the replacement steam generators, despite using a new, more corrosion-resistant alloy that was 10% less heat conductive than the original alloy.
They made up for the 10% loss of heat transfer capabilities by adding hundreds more tubes in the same space, packing them all closer together, and increasing their length by an average of about 50 inches. Additional changes were made as well, usually to prevent corrosion-related problems that had plagued the original steam generators. These changes may or may not have been successful -- we'll never know because somewhere along the line, they completely miscalculated how much steam would be produced inside the steam generators. Outside the tubes (but inside the steam generator casing) there was supposed to be about 96% steam and 4% water. Instead it was over 99% steam, which allowed the tubes to vibrate. The flow rate was much higher than expected, which also caused, or increased, the vibration.
The damage could probably have been prevented by operating the steam loop at a higher pressure, combined with a higher circulation ratio. (The circulation ratio indicates the number of times the water goes around the steam generator before becoming steam, and should be close to five or more, but it was less than four in the SanO SGs.). Adjusting these factors would have meant less steam production -- and less profit. But it might have saved the reactors.
The glitter of gold got them.
How greedy was SCE? Extremely! About a decade ago, they applied for, and received, a power uprate which allowed them to operate the original steam generators (and later, the replacement steam generators) at higher temperatures and flow rates in order to produce significantly more steam -- "pure" profit. The only problem was that doing so accelerated corrosion and fatigue wear in the original steam generators.
Or WAS that a problem, in their view?
Perhaps not, because they planned to bilk the ratepayers for the full cost of the replacement steam generators. And the sooner that happened the better, as far as the utility was concerned.
What they wanted to avoid was to be replacing the steam generators around the time of the next license renewal, in 2022. Accelerated wear followed by an early replacement suited them just fine: That way, they could expect to slide through the license renewal with a "like-new" pair of reactors that they planned to claim was all ready to go for the next 20 or even 40 years. Never mind the waste problem they were continuing to create for everyone, and never mind all the other components that were also wearing out.
SCE delayed some plant upgrades, and separated out the cost of a few items (such as new reactor pressure vessel heads, new turbine blades, miles of new pipes, new control equipment, etc.) to keep the cost of replacing the steam generators themselves below a billion dollars. Thus they were able to appease some activists who complained only about the cost. (Moral: Never complain only about the cost.) The Nuclear Regulatory Commission approved the uprate, and the California Public Utilities Commission approved having the ratepayers pay for it, and SCE turned up the steam output, and the power, and the profits, and shortly thereafter, ordered four replacement steam generators from Mitsubishi.
With the new steam generators installed, the license extensions were expected to be a breeze. The NRC had never denied a license extension and still hasn't.
Then Fukushima happened, and the opposition to San Onofre in the community swelled. American ex-pats came back from Japan to California with their young families, with terrifying stories about the incredibly poor way the Japanese government and many of the Japanese people are handling the radiation crises over there. Highly radioactive rice and vegetables are being downblended with less radioactive products to reduce the dose to "acceptable" levels. Radioactive food is being exported to poor countries as "aid" supplies. Radioactive waste is being shipped around Japan only to be burned (and thus released to the environment) in cities far from Fukushima. And worst of all: Thyroid abnormalities are suddenly rampant among Japanese children and there are rumors of excess numbers of stillbirths and deformed babies that can't survive, of doctors being told not to say anything to the parents -- to just say the baby was born dead.
These returning ex-pats did not want the same thing to happen here. And much of it WILL happen if we have a nuclear disaster.
Less than a year after Fukushima, and less than two years after San Onofre's new steam generators were installed, with opposition to San Onofre in full swing, one tube inside one steam generator leaked. Nearly 40,000 tubes had been replaced, but just one leaky tube spelled doom for San Onofre. They had been hit right between the eyes.
At first, the operators of the plant didn't -- or couldn't -- believe anything serious had happened. So one tube leaked? They called it "settling in."
But then they looked more closely, and the real problem began to reveal itself. This wasn't just teething pains. The steam generators had vibrated excessively, and thousands of tubes had rubbed against tube supports and against other tubes. There was 90% through-wall wear in one tube in Unit 2, which had been shut down for the first refueling after its steam generator replacement, and more than 90% through-wall wear in numerous tubes in Unit 3, with one, -- the one that leaked --, at 100% through-wall wear.
Unit 3 was ruined for sure, at least without yet another billion-dollar steam generator replacement. But the utility thought Unit 2 could be salvaged somehow. Why they thought this, I'll never know, but for more than 16 months they held onto the thought, meanwhile charging ratepayers hundreds of millions of dollars for upkeep for a broken and inoperable pair of reactors.
Finally, on June 7th, 2013, the utility gave up and announced they would decommission San Onofre without trying to restart it, blaming "regulatory delay" which was fair enough, insofar as, the NRC would not grant them a license to restart Unit 2 at 70% power as they had asked. Instead, the NRC came back with dozens of highly technical questions about what assumptions SCE had made in projecting that the reactor could be safely operated at 70% power -- or any percent -- for a five-month "test" period. (Note: The word "test" is in quotes because the utility refused to call their restart plan an experiment with 8.7 million people's lives, but that's exactly what it would have been.)
Whistleblowers, activists and experts alike were also looking at the available data -- which was insufficient in many ways, with much of it held back as "proprietary." But from what was available, all were saying it would be unsafe to restart San Onofre. Even a Senator (Barbara Baxer (D-CA)) and a Congressperson (Ed Markey, D-MA)) got involved, pressuring the NRC to examine SCE's application very carefully.
But did "regulatory delay" really kill the beast? Was it the "miracle" of the busted steam generators (without an accompanying meltdown), or were the activists' campaigns what really killed San Onofre? We'll never know for sure, but the activists certainly put enormous pressure on SCE. Beginning just days after Fukushima, they (we) have been going to local city councils, to schools, political organizations, civic clubs, and to the media, explaining the horrific danger San Onofre presents. And it was working: we had been getting official letters for -- if not outright closure of San Onofre -- safer operation, open investigations, and removal of the waste. Not the brass ring, but good things. We spoke in front of hundreds of elected officials in dozens of cities. Only one or two appeared to express a strongly pro-nuclear point of view, and many that did talk (most just listened) were clearly confused about the dangers from nuclear power. They really did need an education!
The activists brought world-renowned experts to discuss the issues, and many of us spoke without notes, so that we could, with a dozen or more speakers, each telling a three-minute part of the story, offer a very compelling case against nuclear power, complete with pictures, graphs, charts and facts to go along with every claim. And these activists were respected members of the community: retired government workers, Harvard graduates, lawyers, doctors, business persons, moms, dads and kids. All understood the issues and spoke eloquently, time and again. The communities surrounding San Onofre were getting quite an education, and most of these presentations were being broadcast live on the internet.
After a while, one city council would tell another about the group of activists that would come and discuss San Onofre. We would try to have local residents of whatever city we were in speak first.
Activists pointed out, for example, that the energy San Onofre produced was not vital even during the summer months -- there did not need to be blackouts or brownouts. This was true (and is true) even though SCE has refused to convert SanO's turbines to synchronous condensers (basically, big flywheels) for voltage support, has failed to distribute nearly a billion dollars in renewable energy funds it has already collected, has failed to implement much "demand response" (which turns off people's air conditioning and dryers and so forth for an hour or so during peak periods), and has fought all varieties of solar and wind projects tooth and nail to prevent them from hooking in to the grid.
San Onofre will be decommissioned -- or so we're told: I want to see those domes come down before I'll truly believe it. And let's watch out for the radiation that can be released as that happens.
The San Diego daily paper, the Union-Tribune, has always supported nuclear power. It still does. Today (6/20/2013) it published two op-eds: One pro-nuclear by the CEO of General Atomics, and one con by Daniel Hirsch of the Committee to Bridge the Gap.
The CEO's claims are pathetic, ancient dogma about how we "need" energy and will get it one way or another, that renewables aren't ready, that the waste problem can be solved, that the next generation of nukes will be cleaner and safer (don't bet on it). It was sickening to read. Right next to it, John Goldenring and Dan Hirsch (from Physicians for Social Responsibility and Committee to Bridge the Gap, respectively) explain the reality.
Although San Onofre is far less likely to have a catastrophic accident now that it is shut down, the magnitude of the disaster it can have has not diminished by much, and won't diminish much for tens of thousands of years. What to do with the spent fuel -- the used reactor cores -- is a terrible problem which has never been solved by the nuclear industry.
Decommissioning will take decades, and that's not including whatever is done with the reactor cores, which have all been stored on site since the first refueling outage at San Onofre.
Diablo Canyon, a few hundred miles north of San Onofre, is also old and dilapidated , and needs to be closed forever too -- and they also have no solution for their nuclear waste problem. No plant has a solution.
Nuclear power has failed the citizens miserably in California. There has even been a meltdown here -- probably worse than Three Mile Island -- which was covered up and denied for decades. (Dan Hirsch uncovered it.)
It's time to give up on Diablo Canyon too, before something terrible happens there, such as a meltdown. Such as what was narrowly avoided at San Onofre.
Shut down Diablo. It's no better than SanO ever was.
+Ace Hoffman
Carlsbad, CA
The author had been fighting to stop San Onofre for several decades prior to the announcement of its closure. He is a computer programmer and the author of The Code Killers, a handbook about nuclear issues.
Correction: A small number of fuel assemblies were removed at one point decades ago. All the rest are still on site.
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