As knowledge about climate change increases, so does demand for clean energy. Technologies like solar, wind, hydro, geothermal, tidal and biofuels, along with energy-grid designs that will help us take advantage of renewables, are part of the equation, as is conservation.
But many argue that, despite Fukushima and other disasters, nuclear is the best option to reduce carbon emissions fast enough to avoid catastrophic climate change. Because of problems with radioactive waste, meltdown risks and weapons proliferation, some say we must develop safer nuclear technologies.
Even eminent climate scientists like James Hansen claim we can’t avoid nuclear if we want to reduce greenhouse gas emissions. Hansen, a former NASA scientist, with Ken Caldeira of the Carnegie Institution, Kerry Emanuel of the Massachusetts Institute of Technology and Tom Wigley of Australia’s University of Adelaide, wrote an open letter last year stating, “the time has come for those who take the threat of global warming seriously to embrace the development and deployment of safer nuclear power systems.”
“Safe” Nuclear: Is there such a thing
What are “safer nuclear power systems”? And are they the answer?
Proposed technologies include smaller modular reactors, reactors that shut down automatically after an accident and molten salt reactors. Some would use fuels and coolants deemed safer. (Industry proponents argue the low incidence of nuclear accidents means current technology is safe enough. But the costs and consequences of an accident, as well as problems such as containing highly radioactive wastes, provide strong arguments against building new reactors with current technology.)
The Thorium option
One idea is to use thorium instead of uranium for reactor fuel. Thorium is more abundant than uranium. Unlike uranium, it’s not fissile; that is, it can’t be split to create a nuclear chain reaction, so it must be bred through nuclear reactors to produce fissile uranium.
Thorium-fuelled reactors produce less waste, and while some trace elements in spent uranium fuels remain radioactive for many thousands of years, levels in spent thorium fuels drop off much faster. China and Canada are working on a modified Canadian design that includes thorium along with recycled uranium fuel. With the right type of reactor, such as this design or the integral fast reactor, meltdown risks are reduced or eliminated.
Thorium can be employed in a variety of reactor types, some of which currently use uranium – including heavy water reactors like Canada’s CANDU. But some experts say new technologies, such as molten salt reactors, including liquid fluoride thorium reactors, are much safer and more efficient than today’s conventional reactors.
So why aren’t we using them?
Thorium’s downsides
Although they may be better than today’s reactors, LFTRs still produce radioactive and corrosive materials, they can be used to produce weapons and we don’t know enough about the impacts of using fluoride salts. Fluoride will contain a nuclear reaction, but it can be highly toxic, and deadly as fluorine gas. And though the technology’s been around since the 1950s, it hasn’t been proven on a commercial scale. Countries including the U.S., China, France and Russia are pursuing it, but in 2010 the U.K.’s National Nuclear Laboratory reported that thorium claims are “overstated”.
It will also take a lot of time and money to get a large number of reactors on-stream – some say from 30 to 50 years. Given the urgent challenge of global warming, we don’t have that much time. Many argue that if renewables received the same level of government subsidies as the nuclear industry, we’d be ahead at lower costs. Thorium essentially just adds another fuel option to the nuclear mix and isn’t a significant departure from conventional nuclear. All nuclear power remains expensive, unwieldy and difficult to integrate with intermittent renewables – and carries risks for weapons proliferation.
Renewable energy still the best option
If the choice is between keeping nuclear power facilities running or shutting them down and replacing them with coal-fired power plants, the nuclear option is best for the climate. But, for now, investing in renewable energy and smart-grid technologies is a faster, more cost-effective and safer option than building new nuclear facilities, regardless of type.
That doesn’t mean we should curtail research into nuclear and other options, including thorium’s potential to improve the safety and efficiency of nuclear facilities. But we must also build on the momentum of renewable energy development, which has been spurred by its safety, declining costs and proven effectiveness.
With contributions from David Suzuki Foundation Senior Editor Ian Hanington.
Quote: “Thorium Reactors: Back to the Dream Factory
by Gordon Edwards, July 13, 2011
The Nuclear Dream Factory
Every time a nuclear power reactor idea doesn’t work out, and ordinary people get down-hearted and start to doubt the magnificence and benificence of nuclear energy, nuclear proponents rush back to their well-stocked dream factory to fetch another idea — one that is sufficiently unfamiliar and sufficiently untested that ordinary people have no idea whether it is good or bad, safe or dangerous, feasible or foolish, or whether the almost miraculous claims made about it are true or false.
Just a few years ago, nuclear proponents were pushing Generation 3 reactors — enormous plants that would generate huge amounts of electricity, yet be cheaper and faster to build than earlier models, as well as being safer and longer-lived.
Then Areva ran into a blizzard of problems trying to build one of these behemoths in Finland — the cost soaring by billions, the construction time stretched by years, and fundamental safety-related design problems surfacing late in the game. Check and mate.
Undaunted, nuclear proponents quickly executed a 180-degree turn and are now promoting small reactors which can be mass-produced by the thousands and sprinkled on the landscape like cinnamon on toast. Pebble-bed reactors, molten-salt reactors, thorium reactors, have been paraded before the public with as many bells and whistles as the nuclear industry can muster, to distract people’s gaze away from the construction fiascos, the litany of broken promises from the past, the still-unsolved problems of nuclear waste and nuclear weapons proliferation, and the horror that is Fukushima.
The following paragraphs are written to dispel some of the mystique surrounding the idea of “thorium reactors” — a very old idea that is now being dressed up in modern clothes and made to seem like a major scientific breakthrough, which it is not.
Thorium is not a nuclear fuel
The fundamental fact about thorium is that it is NOT a nuclear fuel, because thorium is not a fissile material, meaning that it cannot sustain a nuclear fission chain reaction.
In fact the ONLY naturally occurring fissile material is uranium-235, and so — of necessity — that is the material that fuels all of the first-generation reactors in the entire world. Thorium cannot replace uranium-235 in this regard. Not at all.
Thorium is a “fertile” material
But thorium-232, which is a naturally occurring radioactive material, is about three times as abundant as uranium-238, which is also a naturally occurring radioactive material. Neither of these materials can be used directly as a nuclear fuel, because they are not “fissile” materials.
However, both uranium-238 and thorium-232 are “fertile” materials, which means that IF they are placed in the core of a nuclear reactor (one that is of necessity fuelled by some other material — a fissile material), some fraction of those fertile atoms will be transmuted into man-made fissile atoms.
Inside a nuclear reactor, some uranium-238 atoms will get transmuted into plutonium-239 atoms, and some thorium-232 atoms will get transmuted into uranium-233 atoms.
Both plutonium-239 and uranium-233 are fissile materials which are not naturally-occurring. They are both usable as either fuel for nuclear reactors or as nuclear explosive materials for bombs.
In “Operation Teapot”, the USA exploded an atomic bomb made from uranium-233 in 1955.”
quoted from Dr. Edwards’ site: http://www.ccnr.org/Thorium_Reactors.html
This doesn’t appease non-proliferation requirements at all. A promoter of Thorium technologies (and many other “nukular” technologies) may in-fact be unwittingly involving themselves in nuclear weapons proliferation in addition to the insane associated waste issues.
Technology won’t save us. Think deeper.
Much of the call to switch to renewables is based on the existing amount of energy used in the Canadian economy. But what about the energy (and GHGs) embodied in our imported materials and goods? The West has transferred a helluva lot of manufacturing capability through globalization to China and other developing economies with lower labour rates and often heavily subsidized fossil energy imports.
The price of fossil fuels will continue to climb (400% for oil since the turn of the century) as cheap conventional petroleum tapers off and the much more expensive unconventionals (tar sands, fracked oil & gas) move in to the vacuum as best they can with their significant limitations (high decline rates, low energy return for energy invested, heavy climate impact). Ergo localization.
We don’t have 30 years to replace fossil fuels. The international price may hit an affordability ceiling in less than half that time. This is a very troubling prospect considering the impact that wil have on the world economy, and espcially considering the high levels of debt out there. Investments in all clean alternatives should be made now in an incremental fashion. Coal has killed hundreds of millions throughout its history and is very, very costly when all the health and climate externalities are fully accounted for. To harp about the cost and dangers of nuclear is plain fearmongering when compared to coal.
Fast breeder nuclear technologies like PRISM show much promise should nations like Canada do some real, honest-to-goodness, actual R&D with the goal to fire up its lost manufacturing sector with clean, stable, new energy. Moreover, PRISM burns the waste at the existing second generation reactors over and over, reducing it to a small quantity of glass with a tiny fraction of the radioactive half-life of spent urnanium. Is that fact alone not worth the investment? We have iron ore, chromium, nickel, copper, rare metals …. and a lot of highly educated people with loads of experience. Would that Canada produced its own steel again but this time with electric arc or induction furnaces powered up by emission-free electricity. Would that we replaced Autotopia with train and buses built in Canada.
Wind, solar, tidal and geothermal certainly have their place, but in all likelyhood we’ll end up with an energy deficit should imported Chinese steel and manufactured goods increase in price in lockstep with increasing oil prices and an ageing Chinese population not willing to work for dirt wages anymore in filthy factories.
In my judgement renewables and conservation programs should be developed alongside fourth generation nuclear and distributed to a smart, nation-wide grid. The two should not be separated if there is a policy in place to avoid an energy deficit in the 2020s.
Excellent post MB.
There are 1,000 shades of grey in the green energy equation and 4th generation nuclear designs are necessary part of that solution. Not just because of their economies of scale but because of their ability to use the waste of 1st and 2nd generation reactors as fuel. Whether you love or hate nuclear power the bottom line is that we as a civilization have a moral responsibility to clean up the nuclear waste we have created. Waiting 10,000 years for things to cool down is a cop-out.
As an added bonus even conservative estimates place the energy available in the ‘spent’ nuclear fuel of previous technologies equal to, with the expected increases in energy demands as we grow to 10 billion souls, 200 years of future power.
We in Canada should think of ourselves as the brain trust of the 21st century. We have 23 Nobel Prizes, including ones in physics, with 5 of those in the past 6 years. Let’s get serious as a nation of knowledge workers, develop 21st century clean energy technologies and start exporting green energy and its expertise.
Canada can, quite literally, save the planet. All that’s needed is the courage to look forward and federal and provincial governments guided by sound science
What about the nuclear fusion experiments that were all over the news last week? The researchers were getting very close to a viable alternative, renewable, clean energy that could be the answer to our climate change problems.
Thorium use to producing energy is one type of nuclear. There are many others coming on stream right now from Blacklight’s hydrino to low energy nuclear reaction of Defkalion in Vancouver, to Andreas Rossi’s ‘cold fusion’ which has just been sold for 11 million dollars. There is also Brillouin in Northern California. All of these have been proven and verified by scientists. They will all be competing for the sale of energy even though the media won’t touch them for some unknown reason? This does not mean they don’t exist, as we all know the major scientific institutions of the world denied that the Wright bros. had flown for 4 years after they first did.