Two-in-one: The fusion-fission hybrid can use fusion reactions to burn nuclear waste as fuel (people are shown for scale). It could produce energy and would be used to help destroy the most toxic, long-lived waste from nuclear power.
Credit: Angela Wong
SYDNEY: U.S. scientists have designed a new system that they say could rid the world of radioactive waste produced by nuclear power stations, opening the door to faster, cleaner and more efficient energy production.
"Many people will be willing to give nuclear [power] a chance if the waste could be destroyed," said Prashant Valanju, a nuclear physicist from the University of Texas in Austin.
Valanju is part of a team whose "waste deconstruction" scheme, reported last month in the journal Fusion Engineering and Design, proposes the use of nuclear fusion to break down the waste from existing fission power plants.
Holy Grail
Fission-based nuclear power stations generate electricity from the energy created when large atoms such as uranium are broken apart. This process creates large amounts of energy but also radioactive 'transuranic' waste, which is heavier than uranium and includes plutonium, which can be used to create nuclear weapons.
Nuclear fusion is the opposite process to fission and is the fusion of atoms of hydrogen to form helium, in the same process that powers the Sun. Functional nuclear fusion power plants are one of the Holy Grails of modern physics, as these would not require uranium or create radioactive waste, but the technology is still decades away (see Fusion 2.0, Cosmos Online).
"Existing nuclear fission reactors [can be] used to relatively cheaply destroy 75 per cent of the waste by using a known method that does not create any new transuranic waste," explained Valanju. However, the nasty stuff that remains, nicknamed 'nuclear sludge', is nearly impossible to destroy with fission-only reactors and must be stored.
These waste products continue to be highly radioactive as they break down in a process that can take millions of years, so storing the sludge safely is a major headache.
Hybrid solution
The researcher's new hybrid solution to destroying the waste combines the processes of fission and fusion in the one vessel. Though fusion can't yet be used to generate power (as it eats more power than it produces) it can be used as a powerful source of neutrons, which are fired off when atoms of hydrogen smash together to form helium.
These neutrons would then be used to break apart the heavy radioactive atoms. "The hybrid can destroy the vast majority of this sludge, along with its long-lived biohazardous components," said Valanju.
In the new design, a compact fusion reactor, known as a tokamak, is positioned next to the waste material in a doughnut formation. When combined with a fission reaction, enough neutrons can be produced to break down the nuclear sludge in a constant and steady process.
Science Politics and Money
Your article is an attempt to make people believe that Nuclear Energy production can be safe and environmental friendly.
The nuclear power industry wants to make more nuclear facilities and Cosmos mag is only to happy to facilitate this political agenda by propagating this falseness.
You should not be publishing unquantified theoretical hyperbola; pseudo-science.
It has not been developed and there is no likelihood of it ever being developed and adopted by a financially driven business. Power industries are profitable, not clean and friendly.
None of the proposed reactors, in the world, have plans to use this theory!
Science Politics and Money
Its attitudes like this that would put us back into an agrarian lifestyle. Not bad for some but not wanted by all.
There is no other way at this time or in the near future to provide the power requirements for the world's populations except nuclear. I'm not against solar or wind power but they come nowhere close to being able to provide the needed power requirements.
Here is the reality of today
Here is the reality of today and our society. The ONLY way to save the environment is to USE NUCLEAR POWER. Wind and solar, at present, are not viable technologies to provide our society with power. We just don't have the expendable land area. Wind can only be used in certain geographic locations and solar is at best only 22% efficient, meaning only 22% of light is converted into electricity. If solar becomes 95% efficient then it would be really feasible, you could power your home by moon/starlight.
Nuclear is the only way to go and in 2016, ITER is set to attempt first plasma. If this happens then the world will be witness to the FIRST break-even fusion reaction, then we can finally see the dawning of fusion power.
I Love the environment, but I am also a realist. I would like more environmentally sound solutions, but there are none compared to nuclear.
Lastly, nuclear is also the CHEAPEST option, the price of decommissioning the plant and storing of the waste is INCLUDED in what you pay for electricity and it still costs you less than any other power supply system.
Solar power
Just because solar power in only 22% efficient, it does not mean that it is unable to provide us with energy, it just means that it is currently expensive because we have not invested in researching how to make it better. People who can afford it (from around $10,000) have installed solar panels on their roof and are able to power their homes, feeding excess electricity back into the grid.
If the government were to more heavily rebate solar panels or fund the development of solar technology, instead of throwing money at the coal industry, it could be a viable alternative. Power stations using coal are only around 35% efficient anyway.
You mention only two environmentally friendly options to supply our power, but there are many others including hydropower, tidal power and geothermal energy. More importantly, all these options are renewable, unlike nuclear power.
The two main problems I see with nuclear power are that it is not renewable (it will run out, like coal or other fossil fuels) and that the toxic waste it produces will remain harmful for millions of years, most likely after the human race has become extinct.
We will be better off in the long run if we invest in renewable, non-polluting energy sources now instead of waiting for fossil fuels and uranium to run out.
non-science
You mean similar to the unquantified theoretical hyperbola and pseudo-science produced by the agenda driven IPCC ?.
no nukes head in the sand
After many years in the middle east I see a chronic worldwide negative awareness akin to Galeleo's period. The results of Peak Oil, to some only theory, is actually fact. We must, at this point in our history on this planet, use our minds to stradle this paradigm shift in theory or become fosils for the future detailed story of our demise and the inocent that perish with us. Energy is neither created of destroyed and within theory we must venture forward in our ingorance until maybe we get it right!
nuke waste destruction - too good to be true?
I'm not one for doubting. That was Thomas in the Bible. He had to see Jesus' wounds to believe he had really risen. To read your article about even the toughest nuclear sludge being eaten up through the fusion process is, well, it seems too good to be true. So it is all the more exciting to read about the prospect of such a thing becoming reality.
I'd like to ask more questions to probe a little deeper into the topic, but basically, a new system design is not equivalent with a tested and proven process. It is fascinating that money is being channeled into this kind of research and development, and more than that, it is vitally important, because we have so much nuclear waste already, not counting what will come in the future if more nuke plants go on line. I say - go for more creative scientific endeavors to rid the planet of nuclear waste, and meanwhile also go for developing other sources of energy, renewable ones.
Alternative Fusion
Aneutronic Fusion produces no neutrons and no radioactive waste.
http://www.crossfirefusor.com/nuclear-fusion-reactor/overview.html
To the Eco-fanatics
The eco nuts seem to be missing some very important points:
1) Nuclear power IS renewable. AND BY THIS i mean nuclear FUSION! All you have to do is look up to the big yellow thing in the sky to see how well fusion power works. YES ladies and gentlemen, the sun is powered using fusion reactions, which brings me onto my SECOND point....
2) In nuclear fusion you can use pretty much anything, even things that arnt actually radioactive. That is why fusion-fission nuclear hybrid reactors are perfect for ALL of our energy needs. The Waste from the fission reaction, the 'sludge' as someone called it, will be used again and again by the fusion reaction, even when that sludge loses most of its radioactivity, it will still put out maximum power. AND AFTER, the fission waste products will be 'eaten' by the fission reactor.
3) Pure fusion reactors are not very far off. The Hybrid reactors would only bridge the gap from 'Mostly Fission' to 'Mostly Fusion' power.
4) All other types of 'renewable' energy sources are either inefficient (even more so than fossil fuels) or they take up way too much land, which we'll need to feed the growing populations.
waste
I think the econuts dont really understand nuclear. The right kind of nuclear is sustainable take the sun for instance.
This is essentially like a catalytic converter for nuclear reactors. Like in cars its the partially burnt stuff that is bad and sludgy. Either the heavy elements that havent split in the reactor or even worse elements that have absorbed neutrons and become even heavier and more radioactive. Regular nukes are very inefficient and leave alot behind. When heavy elements split in half the lighter byproducts are only radioactive for about 300 years. Not a long term problem. The heavy transuranics are.
The very high energy neutrons from D-T fusion can cause atoms that aren't fissile in normal reactors to directly split. However in the right kind of fission reactor all of the transuranics can first absorb neutrons and covert to different fissile heavier atoms that can be split. Liquid Fluoride Thorium Reactors which are being designed to convert incredibly plentiful Thorium232 to Uranium 233 can alternatively be run on the unburnt waste from conventional reactors.
In the future whether pure thorium fission or fission fusion hybrid or pure fusion is what we'll ultimately end up using will depend mostly on economics of building the reactors and partially on proliferation.
Thorium for fission in incredibly plentiful, Lithium and heavy hydrogen for fusion are plentiful. The amount of nuclear energy in a single pound of thorium is equal to chemical energy in 5000 tons of coal. Ironically coal has traces of thorium; in 5000 tons of coal there's about 31 lbs lol.