Given the stakes involved, it would be better if people would not take counsel of their fears, and let themselves be educated on the subject. As President Franklin Roosevelt famously said in his first inaugural, "the only thing to fear is fear itself". This is especially true in this subject, as the tendency to be afraid of radioactivity is very easy to acquire. Those who would seek to inspire fear in others would find a useful ally in the subject of radioactivity. We all want to be safe, but excessive fear of harm can be worse than the harm itself.
Well, what about it then? What is nuclear waste? One thing about it is that it is mostly the same stuff than went into it. For nuclear reactors based upon the uranium fuel cycle, this means that most of it is the same uranium that went into it. Less than 5% of the uranium is consumed by the fission reactions before the fuel rod must be retired. Therefore, 95% of the stuff is the same old stuff. It is the 5% that is left over that we are so worried about.
Since the Carter Administration here in the US, reprocessing of spent fuel has been stopped. It has rested in that state since then. This had the effect of playing into the hands of anti nuclear activists, who want to shut down nuclear power altogether. It didn't have the effect Carter had hoped for. In the meantime, new nations are joining the nuclear club and the threat of proliferation is as strong as ever. What should come next?
That's where the Molten Salt reactors come in. These greatly reduce the proliferation risk and the waste problem. The Thorium fuel cycle in a molten salt reactor can not only produce the energy we desperately need in the coming years, but it also fulfills the dream of closing the nuclear fuel cycle promised by conventional uranium light water reactor and breeder reactor designs.
It does this by being a breeder reactor, and by not using a pressurized design. It is a slow breeder, as opposed to the fast breeder, which was to breed new fuel from plutonium. The plutonium was to be reprocessed from the fuel rods of conventional reactors. By breeding the plutonium, and reprocessing, the waste problem was to minimized, yet that didn't happen. However, the molten salt reactor will reprocess and breed its own fuel, while operating in a walk away safe manner. Not only is it walk away safe, it will burn nearly all of its fuel and leave relatively small amounts of waste which will have short half lives.
What's not to like? The Molten Salt reactor using the Thorium fuel cycle will take care of its own waste processing by not producing much at all. That waste that does remain will have short half lives and will no longer pose a threat after a short interval.
But, it is radioactive anyhow. Thorium does has a half life of 14 billion years. It was here before the Earth was, and will be around long after the Earth is gone. With such a long half life, isn't that bad? Isn't it long lived nuclear waste itself?
By the way, what is more dangerous- a short half life radioactive substance, or one with a long half life? Think of it like a match that burns. The half life is how much time does it take to decay by 1/2 of its original mass. With Thorium, it will take over 14 billion years to decay to 1/2 the mass that it has now. There are some substances with half lives that are, let's say, much shorter. If the substance has a half life of 1 second, the match will burn 99.9% of itself within 10 seconds. That's two times two ten times, which is 1024. Thus, one in 1 thousand is equivalent to 99.9%, you see. The comparable rate for Thorium would be 140 billion years. A slow burning match indeed. It can be seen that Thorium is not very dangerous at all compared to the match that burns up in 10 seconds.
It appears that the way to solve the problem is to go into a different direction than the one being followed now. The conventional water cooled reactors are not good enough and should be replaced with LFTRs ( Liquid Floride Thorium Reactors). LFTRs were invented and advocated by the inventor of the light water reactor. But he was ignored and policy drifted down the wrong path until this very day. It is not a new design. It has been proven, but forgotten. It should not ignored much longer. As a matter of fact, it won't be ignored much longer. It appears that the Chinese will pick up where it left off. They will use the American designs themselves as a starter. They plan to have their own reactors up and running within a decade.
It is going to happen one way or another, so it is time to get started before this technology is taken over by the Chinese. It would be a shame to let this one get away from us like so many other things.
Update:
A presentation by Kirk Sorensen on the subject.
Update:
Here's what's inside a spent fuel from a light water reactor
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| http://www.world-nuclear.org/info/inf69.html#DevelopPUREX |
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