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Planned Nuclear Reactors Will Destroy Atomic Waste
separsons writes "A group of French scientists are developing a nuclear reactor that burns up actinides — highly radioactive uranium isotopes. They estimate that 'the volume of high-level nuclear waste produced by all of France’s 58 reactors over the past 40 years could fit in one Olympic-size swimming pool.' And they're not the only ones trying to eliminate atomic waste: Researchers at the University of Texas in Austin are working on a fusion-fission reactor. The reactor destroys waste by firing streams of neutrons at it, reducing atomic waste by up to 99 percent!"
It's fission. They are fissioning minor actinides which normally do not completely fission. This needs a reactor with improved neutron economy (such as a fast reactor), because these MAs will need more than one neutron per atom to fission (usually they will first capture one more neutrons (transmuting in the process) before fissioning).
Not quite. Nuclear waste is mostly made up of un-burnt uranium. The long-lived stuff is mainly even heavier elements than uranium, such as plutonium, americium and neptunium. What these new processes do is to recycle the heavy elements like uranium and plutonium from the waste so that it is all burnt. Thus while you still get the same amount of fission fragments per kilowatt hour of electricity, you don't get any of the heavier stuff mixed into it.
There are three huge benefits to this.
a) The waste fits in a much smaller volume
b) You can get almost 100 times as much energy from the same amount of uranium
c) The resulting waste decays to safe levels within a few hundred years as opposed to many thousands of years.
Since we can easily construct structures that can last a few hundred years, and because the waste volume is so much smaller, this technology would essentially solve the nuclear waste problem. The improved utilization of uranium also makes sure that the fuel will last for any foreseeable future.
The snag is that so far all reactors of this type has been prohibitively expensive compared to existing technology, and there are concerns about how to implement the recycling step in a manner that makes it possible for inspectors to monitor the process to ensure no plutonium is diverted for weapons use.