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Nuclear Risk Expert: Fukushima Fuel May Be Leaking
An anonymous reader writes "Three weeks after the nuclear crisis began at Japan's Fukushima Dai-1 power plant, there's still a real danger of melted nuclear fuel escaping the reactor buildings and releasing a large dose of radiation. So says Theo Theofanous, an engineer who spent 15 years studying the risks of nuclear reactors. Theofanous believes that melted nuclear fuel has already leaked through the reactor vessels and accumulated at the bottoms of the primary containment structures. All attempts to keep the reactor buildings cool may not be enough to prevent the overheated fuel from eating through the concrete floors, he says."
In Uranium mining, there is a technique called in-situ leeching.
In summary, it involves drilling a hole, pouring an acid or alkaline into the hole to dissolve the resource, and pumping it back out.
Once it's out, in the case of uranium, there are a couple of steps involved in turning it into yellowcake.
Given the probability that it is now leaking onto concrete, an alkaline solution would be more ideal.
What would be needed is something like an oil drain pan that resists the chosen alkaline.
The solution would be pumped in and out of the pan into an recovery tank. Uranium in this format is quite similar to the safe-to-handle yellowcake.
Very little reaction would occur - not much more than in nature. Depending on the speed of this chemical reaction, the size of the current breach, and the rate that it eats the steel, it might be possible to use the reactor's own cooling system to supplement the removal process. The key is to remove the fuel, and separate it enough physically that the reaction 'stops'. At this point, damaging the building is no longer an issue. The only important thing is to recover the resource to stop the reaction.
Obviously the rods are no longer able to be removed as one complete unit, or it would be well under way.
We need some miners to step up and advise of the fastest method to dissolve uranium in a steel container and pump it out.
Nuclear engineers are trained in how to make reactors work. Not in how to mine for resources which is exactly what we need right now.
Miners stand the best chance of leaving the area safe.
Contamination only means that there are radioactive elements mixed in with the safe dirt.
Miners are the only experts who know how to extract these resources. If they're gone, then it's safe again.
Even if they replace radioactive contamination with chemical contamination, chemicals are usually easier to deal with in the longer run.
Compare an oil spill to the land around Chernobyl. Chemical spills are problematic for a decade or so.
Anyhow, that's my view. We should treat it like a mine. Mine the resource, make it safe. Get it to a reprocessing facility. Just make sure it is no longer in the reactor in a self sustaining fission state.
Another hopeless optimist. Japan is a high-tech country. Japan is not hampered by an anti-nuclear movement. Japan builds new reactors. Japan's reactors are highly regulated for safety. None of that has prevented them from having aging reactors, operated by a corrupt company. If this can happen in Japan, it can happen anywhere.
Now it's not just a matter of "sealing it and shutting it down": If the core melts through the floor, how are you going to seal that up? The crux with nuclear power is that even undamaged reactors are high maintenance for decades after they've been shut down at the very least. So far nobody has figured out what to do with the "spent" fuel and other radioactive waste. Attempts to bury it have repeatedly resulted in unforeseen accidents with the result that even more radioactive waste needs to be dug up and stored above ground, essentially forever. This stuff isn't just radioactive, it's also extremely toxic and chemically aggressive.
No nuclear facility is insured to an amount that would cover all damages which an accident could cause: No insurer is willing to take the risk. The risk is entirely on the shoulders of the public, who cannot reject it, thanks to representative democracy and bought politicians. The exception to the rule is Austria: In a fluke of common sense, they held a referendum before Austria's first nuclear power plant (completed and ready) was going to be activated: The Austrian people rejected nuclear power and they have not reneged so far.
Oh pooh. Any electrician working at an industrial facility knows exactly how to fix this and with an emergency of this nature the parts would come in via very special delivery very very quickly.
The problems were a LOT more serious - switchgear wiped out, pumps destroyed, no water supply, no instrumentation working, and a lot more.
The IAEA is reporting that measured soil concentrations of Cs-137 as far away as Iitate Village, 40 kilometers northwest of Fukushima-Dai-Ichi, correspond to deposition levels of up to 3.7 megabecquerels per square meter (MBq/sq. m).
Compare this with the deposition level that triggered compulsory relocation in the aftermath of the Chernobyl accident: the level set in 1990 by the Soviet Union was 1.48 MBq/sq. m.
From http://www.japan.org
The first problem is that TEPCO isn't telling anyone what they know (to save face and because they're freaking out)
The second problem is that whatever they are telling, they're telling to the Japanese government and no-one else (even their own workers, who they convinced to wade through radioactive water without boots, go into radioactive buildings without radiation badges or suitable gear, etc).
The third problem is that the experts are working with minimal data - and what they do have is suspect
The fourth problem is that TEPCO has been trying to salvage the reactors at the same time as spraying them with seawater (which would be corrosive) and after the outer shell had exploded on three of them (causing untold damage to electronics, shock-proofing, etc)
On top of all that, TEPCO allowed the hydrogen build-up in the first place. They could have burned it off with a controlled burn. This would have prevented the explosions, reduced the spillage and possibly prevented the fuel leak. (Reducing pressure may have reduced water temperature and may have conserved some of the cooling pools.)
As for building the reactors ALONG the fault-line, despite advice not to by their own chief scientists, and building a tsunami wall far lower than the historic tsunami wave-heights....
This accident was stoppable at so many points in so many ways. The problem wasn't so much the reactor alone as the mindset together with the reactor.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
The authorities don't know how the water is leaking out and don't know the upper bound on the total amount of radioactivity released. The lower bound is already rather staggering. In addition, radioactive materials have already leaked into the ocean and the ground water. TEPCO said the level they measured in the ground water was the similar to the high levels found in the turbine buildings and the tunnels outside the plants. The Japanese Nuclear and Industrial Safety Agency said those readings were way too high so they asked TEPCO to measure again more carefully.
The only specific theory I've heard of how the thousands of tons of highly radioactive water got out of the containment vessel is that it got out via graphite seals in the bottom of the vessel. There are holes there for control rods and the holes are blocked with graphite seals. The seals will fail at high temperatures and melted fuel rods falling to the bottom of the vessel would provide more than enough heat to cause the seals to fail. If it is any solace, reactors that don't contain melted fuel rods probably don't have leaks all over the bottom of the containment vessel.
The radioactivity released at Chernobyl escaped upward into the air. This made it easier to get a handle on the magnitude of the total amount of radioactivity released. The release at the light water reactors at Fukushima is for the most part traveling downward, to basements, tunnels, ground water, and the ocean. This makes it extremely difficult to get a handle on the total amount of radioactivity that has been released. They really don't know of the bulk of it is in the thousands of tons they have already discovered or if that is just the tip of the iceberg.
We don't see the world as it is, we see it as we are.
-- Anais Nin
Nuclear power also has several strikes: * * High maintenance - everything has to work all the time so that your plant doesn't explode and make hundreds of square miles uninhabitable
* * High initial cost
* * High shutdown costs
* * stuck with billion-dollar boiling water reactors and pressurized water reactors
As the Fukushima accident showed, everything doesn't have to work right. The high cost thing is a real problem. And you're just repeating yourself with the last point.
The best argument in favor of nuclear power is that "it may have problems, but it's all we've got". Nuclear advocates rightly point out that, compared to coal, oil, natural gas, and even hydropower (complicated), perhaps nuclear isn't so bad. Coal is abundant but dirty, oil is expensive and dirty, natural gas is cleaner but still poisons the ocean with CO2, and hydropower has it's own challenges.
I hate to say it, but the economic argument for nuclear power is the weakest link. It's all heavily subsidized with liability protection that no other industry (well to my knowledge, which isn't so hot) has.
GRC's site talked about applying the technology to tar sands, to coal mining, breaking down hundreds of millions of used tires piled everywhere... How would the energy equation change if harvesting coal and tar sands didn't require massive amounts of energy?
The problem is that these do require significant amounts of energy either to harvest or to turn into a viable vehicle fuel. If the energy is cheap enough, then you can do things like the above to produce vehicle fuel.
That leads to the fundamental problem in your calculation. Vehicle fuel is not just any form of energy, but a rather costly one. If you're going to make it using exotic methods like the above, you will need a cheap source somewhere, perhaps nuclear power (if they ever get the issues sorted out).
What if Raphial Morgado's MYT (Mighty) pump really is as good as he says it is? Suppose you could get 25% more water pumped for the same amount of electricity, or generate 25% more electricity with the same amount of steam?
That's not much of a saving. And it probably is not petroleum powered.
If supply exceeds demand by a significant percentage, we'd be back to $1/gallon gas in a heartbeat.
Supply never exceeds demand for very long in an oil market. Where would the oil be stored?
At Chernobyl, they tunnelled under the reactor and created a huge concrete shield.
It acted as a heat sink, and as a way to reduce leakage of radioactive materials into the groundwater.
300 miners worked on the project.
That's not how a reactor works.. Sure, you "shut it down" by inserting the control rods, but it's not an off switch. It needs days to cool down, all the while still able to heat water and spin turbines.
I don't know what was providing systems power and how that was lost.
mod me funny
Insightful my fat arse.
Here in Germany the power companies basically had a choice: either they shut down all their reactors by a set date or they transfer operational time between reactors so newer and safer ones can run longer, and older could be shut down sooner.
What did the power companies do? They transfered the operational times from new reactors to old ones since they were cheaper to operate, already written off decades ago and thus generated pure profits of about one million euros every operating day.
"It's such a fine line between stupid and clever" -- David St. Hubbins, Spinal Tap