Tuesday, March 15, 2011

When reactors go bad: Loss of coolant accidents and their human consequences

Rod Adams and I have a disagreement. Rod is a very smart guy, and I admire him a lot, but I disagree with Rod about some nuclear technology concepts. For example, Rod believes that Light Water Reactors are good enough for our current energy needs. My view is that significant improvements are possible and the spread of better nuclear technology would be greatly facilitated by introducing technological changes. Reactors can be made significantly safer, built at a lower cost, with a virtually limitless fuel supply, and the problem of nuclear waste can be virtually solved. All of this can be accomplished with a relatively modest research and development investment. Note that I did not mention nuclear proliferation. No one in his or her right mind would dream of using light water reactor technology to produce plutonium for nuclear weapons.

Rod recently remarked to me,
We know how to produce, fuel and operate light water reactors safely and economically now. Many of us know they are not the ultimate technology, but we also know that prosperous light water reactor owners are far more likely to be interested in investing in the next big fission technology . . .
In other words "hay, it is my business, don't run it down."

My disagreement with Rod is more a mater of emphasis than a fundamental disagreement. Indeed I view the Light Water Reactors currently in use to by no means be examples of bad industrial designs. Generation II reactors like the Japanese reactors that are now in so much trouble are both safe for everyday operation and reliable. Only an unforeseen, unusual and extreme condition, a 9.0 magnitude earthquke, one of the largest in human history, brought them down. Indeed the Japanese reactors were proven by the recent earthquake to be remarkably safe. The reactors themselves were designed to survive an earthquake of a 7.9 magnitude, but they survived a magnitude 9.0 quake. Their undoing was the effects of an extraordinary tsunami on their emergency coolant systems. Still despite generally preforming well, a flaw that was never foreseen, began to destroy several Dai-ichi reactors, and the problems have, as yet, not been controlled.

It is clear that 40 years ago, the Japanese engineers who designed the Fukushima Dai-ichi nuclear plant did not expect a ten meter tsunami, and may not have been even aware that such a tsunami was possible. At any rate the designers of the Fukushima Dai-ichi nuclear plant failed to prepare for a earthquake and Tsunami of the recent magnitude. The consequences are very unpleasant, but hardly the sky is falling disaster portrayed by the chicken littles of the ever incompetent New York Times:
Japan’s nuclear crisis verged toward catastrophe on Tuesday after an explosion damaged the vessel containing the nuclear core at one reactor and a fire at another spewed large amounts of radioactive material into the air, according to statements from Japanese government and industry officials.
Needless to say, things are not going well in the Japanese effort to control events at the Fukushima Dai-ichi plant, but a catastrophe it is not. As I noted yesterday,
People are beginning to use the term "nuclear disaster," to describe the Japanese reactor problems which are actually a part of the aftermath to a real and huge disaster, the Japanese earthquake/tsunami. The word disaster is used in this case in a quite loose fashion. The normal characteristics of a disaster include loss of life, wide scale material damage to property, and undesirable changes to the environment. It is not clear that the problems at the Japanese reactors minimally qualify as a disaster. There has been no damage to property outside the reactors themselves, and no loss of life. The real disaster was the earthquake/tsunami event of which the reactor problems are consequences. Thus the use of the term "nuclear disaster" seems inappropriate.
Panic and fear are contagious, and people who are vicariously witnessing potentially distressing events, may catch fear. What is most unfortunate is the role of Journalists in spreading the fear rather than offering a detached professional attitude. Events such as the
Fukushima Dai-ichi accidents offer ideologically driven journalists, an opportunity to grind their axes. They are deliberately spreading fear and panic. For example, Greg Palast tells us,
Nuclear plants the world over must be certified for what is called "SQ" or "Seismic Qualification." That is, the owners swear that all components are designed for the maximum conceivable shaking event, be it from an earthquake or an exploding Christmas card from al-Qaeda.

The most inexpensive way to meet your SQ is to lie. The industry does it all the time. The government team I worked with caught them once, in 1988, at the Shoreham plant in New York. Correcting the SQ problem at Shoreham would have cost a cool billion, so engineers were told to change the tests from "failed" to "passed."
But the problem at Dai-ichi was not earthquake related failures. it was tsunami related as Palast acknowledge,
Last night, I heard CNN reporters repeat the official line that the tsunami disabled the pumps needed to cool the reactors, implying that water unexpectedly got into the diesel generators that run the pumps.

These safety backup systems are the "EDGs" in nuke-speak: Emergency Diesel Generators. That they didn't work in an emergency is like a fire department telling us they couldn't save a building because "it was on fire."

What dim bulbs designed this system?
Palast then unleases his anti-nuclear fanaticism,
In my New York investigation, I had the unhappy job of totaling up post-meltdown "morbidity" rates for the county government. It would be irresponsible for me to estimate the number of cancer deaths that will occur from these releases without further information; but it is just plain criminal for the TEPCO shoguns to say that these releases are not dangerous.

Indeed, the fact that residents near the Japanese nuclear plants were not issued iodine pills to keep at the ready shows TEPCO doesn't care who lives and who dies, whether in Japan or the USA. The carcinogenic isotopes that are released at Fukushima are already floating to Seattle with effects we simply cannot measure.
Engineer Keith Yost assessed the media coverage,
As a nuclear engineer, it is depressing to read the recent reports on the Fukushima nuclear incident — not because of the incident itself (at this point I strongly believe that we will remember Fukushima as evidence of how safe nuclear power is when done right) — but because the media coverage of the event has been rife with errors so glaring that I have to wonder if anyone in the world of journalism has ever taken a physics class. My favorite: in one article, boric acid was described as a “nutrient absorber” instead of a “neutron absorber.” How many editors signed off on that line without asking, “Why would a nuclear reactor need to absorb nutrients?”

Whether it is confusion of radiation with radioactive material, flailing comparisons to past accidents, or hopeless misuse of terminology, reporting on Fukushima has been a mix of hype and speculation entirely devoid of useful information. Let’s set the record straight: the situation is under control, it is unlikely that the nuclear fuel has melted, the risk to the public is effectively zero, and, depending on whether facts on the ground have been reported correctly, it is possible that the reactors will remain capable of producing power in the future.
When reactors go bad the consequences, with the exception of Chernobyl, hardly qualify as disasters. But one human consequence is the spread of panic and fear. The words "reactor meltdown," are associated both by the media and by the public with panic and fear. Thus we leave the rational world of strict definition and enter the world of connotation.

The panic in the United States is reaching absurd proportions. People are rushing to drug stores to buy iodine anti radiation tablets. I kid you not. Alan Morris, president of Virginia-based supplier, Anbex Inc., told of selling out his entire supply of iodine tablets.
Those who don't get it are crying. They're terrified,
Morris said.

We cannot escape the problem. We may say with all rationality, that the consequences of the Dai-ichi events will not lead to wide scale property damage, large numbers of deaths, and many cases of radiation sickness, but the public will probably not hear us.

8 comments:

Anonymous said...

Charles, the situation in Japan is very serious. If their spent fuel pools dry out the result could be very bad.

We can point out that the routine operation of coal plants kills 11,000 Americans each year and the mercury lowers the IQ of thousands of newborns.

We can point out that Gen III reactors would have come through this event well. They have passive cooling systems that do not need power to work, and have core catchers, making a full meltdown nothing to fear. Some designs can be licensed to start up without external power, a very helpful feature in this kind of disaster.

Bill Hannahan

EL said...

"It is clear that 40 years ago, the Japanese engineers who designed the Fukushima Dai-ichi nuclear plant did not expect a ten meter tsunami, and may not have been even aware that such a tsunami was possible" (Nuclear Green)

A look at historical tsunamis prior to 1971 suggests many above the 6.5 meter mark planned for by the Fukushima (1971) reactor design:

Nankai, Japan (1854): 25 meters
Krakatoa, Indonesia (1883): 40 meters
Kanto, Japan (1923): 12 meters
Newfoundland (1929): 7 meters
Showa Sanriku, Japan (1933): 10 meters
Valdivia, Chile (1960): 25 meters

Jason Ribeiro said...

Charles, your last sentence is very foretelling. In Three Mile Island, there was nothing for the public to see. The Chernobyl explosion was not caught on tape but the fire aftermath was. However, the two Fukushima explosions caught on video will be powerful ammo for the anti-nuke movement for years to come. We can be thankful no one was killed from those explosions but no matter how much rational explanation is put behind this situation, those images will remain forever.

David Herr said...

I disagree with Mr. Yost's claim that "it is unlikely that the nuclear fuel has melted." Given the length of time that the core was uncovered, partially or, in the case of Unit #2, fully, there has almost assuredly been fuel melting. At TMI, it took about about 3 hours for the fuel to start to melt, and by the 4th hour, there was a molten pool of corium at the bottom of the pressure vessel. The top and bottom crusts of the melt area impeded coolant flow.

All that having been said, the pressure vessel retained the molten corium, and did not even come close to being melted through. The question here is, are the Fukushima RPVs as robust as those at TMI, and does the configuration of the BWR, with it's torus wet-well below the RPV, more susceptible to releasing core materials to the environment.

At this point, although the optics of exploding secondary containments are terrible, I doubt that the core will be exposed to the atmosphere.

However, now is the time to stop extending licenses for Mark I containment reactors, beyond the time necessary to replace them with ESBWRs. That would be 23 reactors here in the US, enough to get some economies of scale. Then, at the end of that process, hopefully MSBRs will be ready for deployment.

donb said...

David Herr wrote:
However, now is the time to stop extending licenses for Mark I containment reactors, beyond the time necessary to replace them with ESBWRs.

I am glad that Mr. Herr provided this context. If am sure that if a public official had said this, only the part about not extending licences would have come through in the media.

Even this carefully worded statement needs to be studied. Taking it straight on, we have new, safer reactors replacing older ones. This is fine as far as it goes.

But my preference is to maximize the use of nuclear power. If shutting down a well run old reactor results in more fossil fuels being burned, we have a net decrease in safety. The type of hazard may have shifted, but I don't believe that reactor accidents cause severe death, in contrast to fossil fuel power plants causing mild death.

From what I see, the LFTR would be even a safer choice, and we should be going full speed ahead on work to build a demonstration reactor. In the mean time, we need to be careful to not make the better (ESBWRs)the enemy of the good (Mark I containment reactors) when the alternative (fossil fuels) is so much worse than either.

Greg Barton said...

This why, in the next years, it's important that every time the video is shown or mentioned in a forum where you can respond, you should respond. If it ends up being the case that no one is killed and/or no one gets sick, just mention that. Emotions fade with time. Hopefully facts can take their place.

Sione said...

Some of you guys are in denial. Time to face reality.

As far as the public is concerned the facts demonstrate that nuclear reactors are dangerous. They explode. They pollute. That's the end of the discussion right there. People are not going to listen to nuke "experts" making fine distinctions between reactor types and claiming how the latest flavour-of-the-month type is safe. Why would they? All they know for certain is that generations of government and related crony spokesmen have boasted of how safe nuclear reactors are supposed to be. They contrast that with what they witness in the real world- disasters and near disasters, various failures, corruption, catastrophes and near catastrophes, unimaginably powerful weapons, polluted environments, wrecked property, ruined lives...

As for the nonsense about fossil fuels being "worse" than nuclear- get a grip! People are not going to give that self-serving rationalisaton anything other than contempt and instant dismissal.
Look, if this is the best nuke enthusiatsts have got, then total frustration and woeful disappointments await. Oh, wait, isn't that what's been the case since the '70s?

The nuclear welfare program (it isn't accurate to call it a productive industry or a sustainable business really) is a failure. For nuclear technology to ever contribute as a major productive industry in the US and elsewhere it is necessary to reassess the entire activity in all its aspects from first pronciples. That includes the technology (fuel cycle etc), economics (who funds it and how, who benefits and how), administration (rules and regulations, insurances, liabilities, safety, guarantees etc), property issues, nuclear pollution (of all types), who should take part and who should operate in an industry (why those folk and why not others), matters of strict liability, criminal liability, morality, human rights and so on. Doing all that is going to take some extended period of time. Evading it guarantees that nuke retains the tainted status of the hideous pederast lose in the community.

Sione

LFTR_Fan said...

==> Fukushima, M9 earthquake, Tsunami, reactor disasters, political panics, media meltdowns, anit-nuke holiday, catnip for the windy/sunny bunch -- now what?

As of 25 Jan 2011 the Chinese Academy of Sciences launched a development program for Thorium Fueled Molten Salt Reactors (TFMSR's). This is a "green" nuclear solution, thanks to Oak Ridge research done in 1965-1969. TFMSR's won't be an instant replacement for the existing reactors, but they'll be the best possible alternative. Google "Energy From Thorium" and "Thorium Energy Alliance" for the rest of the story.

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