Environment

Hitachi developing reactor that burns nuclear waste

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Hitachi is developing a new reactor that burns transuranium elements, such as those produced by this advanced test reactor at Argonne National Laboratory (Image: Argonne National Laboratory/Wikimedia)
Hitachi is developing a new reactor that burns transuranium elements, such as those produced by this advanced test reactor at Argonne National Laboratory (Image: Argonne National Laboratory/Wikimedia)
Diagram of Hitachi's nuclear-waste burning reactor system (Image: Hitachi)

The problem with nuclear waste is that it needs to be stored for many thousands of years before it’s safe, which is a tricky commitment for even the most stable civilization. To make this situation a bit more manageable, Hitachi, in partnership with MIT, the University of Michigan, and the University of California, Berkeley, is working on new reactor designs that use transuranic nuclear waste for fuel; leaving behind only short-lived radioactive elements.

In popular imagination, nuclear waste is a wildly radioactive goo that glows like the back end of a lightning bug. But in real life, the real problem of nuclear waste isn't the "hot" stuff, but the mildly radioactive elements with atomic numbers greater than 92. That’s because highly radioactive elements have short half lives. That is, they burn themselves out very quickly – sometimes in a matter of minutes or even seconds.

On the other hand, mildly radioactive elements, such as plutonium, have half lives measured in tens of thousands or even millions of years. That makes storing them a very long-term problem, and is a particular difficulty in countries like the United States that don’t recycle transuranium elements by fuel reprocessing or fast-breeder reactors.

Diagram of Hitachi's nuclear-waste burning reactor system (Image: Hitachi)

What Hitachi and its partners are trying to do is to find ways to design next-generation reactors that can use the low-level transuranium elements as fuel; leaving behind the high-level elements to quickly (relatively speaking) burn themselves out in no more than a century or so.

That’s not a particularly new idea. Some modular nuclear reactors already use nuclear waste as fuel. But what sets Hitachi apart is that it's looking into designs based on current boiling-water reactors that are known as Resource-renewable Boiling Water Reactors (RBWR) and are being developed by Hitachi and Hitachi GE Nuclear Energy Ltd.

The idea is to develop a new fuel element design using refined nuclear waste products along with uranium that can be installed in a standard boiling water reactor. This would not only make such reactors more economical to build, but would also use decades of safety and operations experience to achieve efficient nuclear fission in transuranium elements.

Hitachi says that it’s already carried out joint research with its partners starting in 2007 and is now concentrating on the next phase, which deals with more accurate analysis methods, as well as reactor safety and performance, with an eye toward practical application of what’s been learned.

Source: Hitachi

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16 comments
Bob Stuart
Countries "like the US, which doesn't recycle nuclear fuel" are the only kind of country. Some others have tried, but failed very expensively. This is a nice idea, but so far, it looks like another PR stunt by a deadly industry.
Mark Pawelek
The US developed a reactor, the Integral Fast Reactor (IFR), able to recycle nuclear fuel between 1984 - 1994. This was closed down by Clinton's democrats with John Kerry and Al Gore leading the way. Since then it's been banned on the spurious ground of proliferation - despite being no proliferation threat because it was designed to be proliferation resistant. GE-Hitachi have the commercial version of the IFR. It's called PRISM. It's no wonder that people will fail expensively when environmentalists ban their technology.
Stephen N Russell
reuse idle N plant sites for this alone, hoorah, yes mass produce for reuse alone More jobs for N Industry alone Can reactor work in ships & subs??
Neil Farbstein
Its not right to call plutonium slightly radioactive., Its extremely radioactive and a small dust mote can give you cancer if you inhale it.
Timothy Foley
I remember reading about thorium reactors a few years ago after the Japanese disaster. They are capable of burning waste and much safer. Their main problem was lack of funding for a startup company and the political power of the biggies like GE. The market will allow these good ideas to fail in the face of well capitalized competition. Government may be needed for change here. Not everywhere but maybe here.
KronosFire
Facts won't go away no matter how much PR. Stable isotopes like 240Pu don't fission, which is why they are not refined and used in weapons. And, as we saw so very well at Fukushima Dai-Ichi #3, 238Pu has a nasty tendency to continue fission WITHOUT water, crippling one of the major 'safety' features of the LWR. As for the putative 'success' of breeders, I remind you that Russia, China, France and even the Brits tried building breeders, had accidents, and barely avoided catastrophes, thus terminating those projects. ALL cases of breeders have proved unreliable. ALL. And that's why you don't see them in the market. Meanwhile, back at the Al Gore / Jimmy Carter hating ranch, reality is that the permanent sequester costs far exceed the value of electricty
StWils
Anyone know how well this lines up with ongoing work on Thorium based fission such as the reactor project being sponsored,in part, by Bill Gates? Thorium can burn other isotopes while releasing something like 40,000 times more energy than uranium. The eventual end state is lead.
quax
This is by far not the only design that can burn nuclear waste, personally I much prefer inherently safe approaches:
http://wavewatching.net/2012/09/23/transmuting-waste-and-worries-away/
physics314
Far from unreliable, the BN-600 reactor, a sodium-cooled, fast neutron breeder reactor, has been supplying electricity to the Soviet/Russian grid for almost 35 years. Important in this context is that breeder reactors extract much more energy from the fuel than thermal neutron reactors, and generate spent fuel that is much shorter-lived. Following the success and lessons learned from the BN-600, a second reactor, BN-800 is in initial operation, and and more are in the plans.
The massive amount of radioactive waste, and associated storage problems, are mostly political, not technical in nature - in no small part resulting from misguided proliferation fears that had the Carter administration kill the fast neutron reactor technology in the US.
ezeflyer
We already have the largest reactor by far, one that can power the entire world if we capture its energy, the sun.