Have you ever heard of Admiral Rickover? Fans of "The Hunt for Red October," the 1990 thriller starring Sean Connery as a rogue Russian submarine captain, may know that Rickover is the U.S. admiral responsible for creating the world's first nuclear-powered sub.
Considered "The Father of the Nuclear Navy," Hyman G. Rickover moved up the ranks during the World War II, and then afterwards was tasked with developing a system of naval nuclear propulsion while working for the Atomic Energy Commission - an agency whose role, ironically, was to work out how atomic energy could be used for civilian purposes rather than military ones.
After the war, the United States was experimenting with different fuels for generating a nuclear reaction, and the leading contenders were uranium -- the metallic element "U" on the periodic table of the elements -- and thorium -- represented on the table as the symbol "Th." Uranium's chief advantage over thorium was that it could be used to produce both atomic weapons and nuclear power, while thorium, unlike uranium, is not "fissile" - meaning it cannot be split to make a nuclear chain reaction - and could only be applied to nuclear power.
With the United States in the early stages of an arms race against the former Soviet Union to develop a nuclear arsenal, it was easy to see which element would win out. While thorium was used in a later version of America's first civilian nuclear power plant -- also headed up by Admiral Rickover -- it would take a back seat to uranium as the primary fuel for nuclear reactors.
Less Radioactive Waste
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Recently, thorium has generated a fair amount of excitement for its potential as so-called "green nuclear" power, especially in the wake of the Fukushima Daiichi nuclear plant meltdown that occurred after the 2011 Japanese tsunami. Fukushima may have soured the world on nuclear, with many people calling it too dangerous and calling for its end, but nuclear power plants remain a cheap, reliable and relatively clean source of electricity compared to their fossil-fuel cousins, coal and natural gas.
What's green about thorium? First, thorium reactors are more efficient than uranium reactors, because they waste less fuel and produce far more energy. Most nuclear power plants are currently only able to extract between 3 and 5 percent of the energy in uranium fuel rods. In molten salt-cooled reactors, favored by many thorium proponents, nearly all the fuel is consumed. According to a pro-thorium group of British lawmakers, one metric tonne of thorium delivers the same amount of energy as 250 tonnes of uranium.
Second, and perhaps most important from a "green" perspective, thorium yields little waste and is less radioactive. According to its proponents, residue from the thorium reaction will become inert within 30 years, compared to 10,000 years for radioactive waste currently generated from uranium reactors.
A further advantage thorium has over uranium is its relative abundance in the Earth's crust. The silvery-black metal is estimated to be three to four times more plentiful than uranium, with large reserves existing in China, Australia, the United States, Turkey, India and Norway. Tons of it are known to be buried in the U.S., since thorium is a by-product of rare earth mining.
China Aims For First
So, if thorium is such a wonder-metal, why hasn't it been accelerated? (Pardon the pun.) There is currently a race on to develop a functioning thorium reactor, with the number one and two positions held by China and Norway. Last year, Thor Energy, a private Norwegian company, started producing power from thorium at its Halden test reactor, with help from nuclear giant Westinghouse. Uranium-poor India and France are among other countries developing thorium research programs.
All of them, however, will be chasing China, which according to a recent Telegraph article, is "going for broke" to build the first thorium reactor within the next 10 years. The project reportedly started with a budget of $350 million and the recruitment of 140 scientists at the Shanghai Institute of Nuclear and Applied Physics. It plans to have 750 employees by 2015.
So should the nuclear industry herald the death of uranium and make way for this new thorium darling? Not so fast, skeptics say.
Long Road Ahead
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One large hole that can be punched in the argument for thorium involves the economics of thorium reactors. Experts say compared to uranium, the thorium fuel cycle is more costly and would require extensive taxpayer subsidies.
Another issue is time. With a viable thorium reactor at least a decade away if not more, the cost of renewable alternatives like solar and wind may come down to a point where thorium reactors won't be economical. Critics also point out that the nuclear industry has invested too much in uranium reactors - along with government buy-in and a set of regulations around them - to be supplanted by thorium.
As for the "green nuclear" argument, thorium's detractors say that isn't necessarily the case. While thorium reactors produce less waste, they also produce other radioactive by-products that will need safe disposal, including U-232, which has a half-life of 160,000 years.
"It will create a whole new volume of radioactive waste from previously radio-inert thorium, on top of the waste from uranium reactors. Looked at in these terms, it's a way of multiplying the volume of radioactive waste humanity can create several times over," said Oliver Tickell, author of Kyoto2, speaking to The Guardian.
Will thorium be a fool's errand or the fuel that heralds the dawn of a new age of nuclear power? It is certainly too early to say, but one thing is for sure: thorium has great potential and with the right backers, could become a viable adjunct to uranium, if not a serious competitor.
By Andrew Topf Oilprice.com
With over a decade of journalistic experience working in newspapers, trade publications and as a mining reporter, Andrew Topf is a seasoned business writer. Andrew also… More
Comments
They Use up 96% of there fuel, would not have to be changed out constantly as the Uranium Reactors do, and much of the fuel could be the old Uranium waste that has piled up over the last 60 years.
What waste there is would be so much less in volume it is a farce to just poo poo the idea of Thorium Reactors.
Look at the Data and put that in your article next time.
The quote from Oliver Tickell is taken out of context or just plane wrong. Do more research on that issue.
U-233 has a 90% rate of fission. The remaining (unfissioned) 10% becomes U-235, which has a 85% rate of fission. The remaining 1.5% of the original Thorium turns into Plutonium-239, which fissions at a rate of about 40% in a slow-spectrum (light water or molten salt) reactor. So the ultimate long-term transuranic waste produced is less than 1% of the original Thorium mass.
If you run on U-235, you're already halfway to Plutonium, and with a fission rate of 85% you wind up with 15% of the original load turning into Pu-239, 40% of which fissions, leaving about 8% of the original U-235 mass as long-term waste.
Th-232 is 4X as abundant a Uranium, and it's good to go right out of the ground. There's no such thing as enriched Thorium.
Thorium (or for that matter, any atomic fuel) would best be exploited in a Molten Salt Reactor, because the fuel would be in a liquid state. The main fission product that poisons nuclear fuel is Xenon-135, which is a gas. It bubbles right out of liquid fuel, but gets trapped in solid fuel rods, spoiling the rods long before all their fuel can be utilized. That's why we have so much long-term waste.
So the real hope for a clean energy future isn't just thorium, but thorium-fueled molten salt reactors.
One thing Oliver Tickell failed to mention was that molten salt reactors can use the waste from the current light water, solid fueled Uranium reactors, to produce more energy. As mentioned in the article, the current light water reactors consume a very tiny fraction of the fuel's nuclear energy. Molten salt technology can squeeze out the rest of that unused energy. This recycling feature greatly reduces the half life of our nuclear "waste" stockpiles. Where most people see waste, molten salt advocates, like myself, see perfectly usable fuel. For those interested in learning more about this, there have been a few TED talks discussing this potential.
Also, U-232 has a half life of 69 years, not 160,000 as stated in the article. If the author was referring to U-233, the U-233 is not waste at all. U-233 is the fissile part of the fuel that is consumed in the reactor. So, in that sense, disposal of U-233 is not an issue.
Th-232 has a half life of 14 billion years--meaning it is very stable and quite safe to handle with bare hands. A 14 billion year half life does *not* mean that the stuff is dangerous for 14 billion years. It simply means that in 14 billion years a given amount of the material will be half as radioactive after 14 billion years (in terms of Becquerels, or decays per second). Th-232 emits helium nuclei, but at a *very* slow rate.
But it's absolutely essential, now that we haven't eliminated combustion power by 2000, as we would have if Nixon and others hadn't fumbled & combustion folks hadn't lobbied.
The news now is exceedingly bad economically and environmentally: http://tinyurl.com/n2qnos6
https://www.youtube.com/watch?v=wtQxF_3BSxQ
Thorium is great for long-term waste/weapons advantages, but we simply need as much nuclear of any kind as possible, now. Juts to address ocean acidification demands over 1teraWatt of hi-temp clean power (IFR, MSR) running 24/7 for materials processing to protect ocean chemistry being ruined by CO2 emitted over the Industrial Age. There is an extinction event arriving before 2050 that will be far more expensive than what climate change can wreak in that time.
--
Dr. A. Cannara
650 400 3071
http://tinyurl.com/nu5o7k5
http://tinyurl.com/cxplxx3
"The experts from the Oil, Gas, Coal, Nuclear, and Renewables industries do protest too much, methinks."
Now enter Thorium. The Molten Salt reactors the US experimented with in the 1960's appear to be the ideal nuclear engine. Most of the objections raised by anti-nuclear people are completely baseless. Still, there are many unanswered questions, such as how Fluoride salts react with water. Even if they are as dangerous as Sodium, the French have demonstrated that even molten Sodium can be handled safely.
The biggest problem with Thorium reactors is the lack of interest. With a set of realistic specifications and enough money, there's no reason safe/ efficient American Thorium reactors can't go commercial in the next 10 years. The Chinese are committed. The only question is who will own the patents.
Water cooled reactors operate from 75 to 150 atmospheres.
MSRs operate around 1 atmosphere. This reduces all piping thickness.
MSRs core materials don't flash into steam nor produce hydrogen / oxygen like water cooling does. This allows for a secondary containment structure which is a small fraction the size of water cooled reactor containment.
MSRs require far simpler and less safety / support systems to operate a reactor. Water cooled reactor require about a half a dozen costly operational / safety systems (steam generator, low/medium/high pressure injection systems just to name a few).
MSRs can be easily designed to avoid all computer / man in the loop so that in case of any temperature increase above normal or loss of electricity to the reactor, the reactor shuts itself down automatically, relying just on physics.
LFTR reactors are an advanced for of MSR reactors that efficiently breed U-233 from Thorium, which includes an integral reprocessing facility similar to Sodium Fast Integral reactors.
U-232 is also fuel on LFTR reactors and are simply fissioned along with U-233 and some other byproducts made when U-233 absorb neutrons instead of fission (U-234, U-235, ...).
use can be over come.
Carlos Davalos LVN
For instance, if this works, in theory new nuclear reactors could be built in California. California banned new reactor construction, unless they close the fuel cycle, which the next fuel test on Halden will prove (replacing the Plutonium in the fuel with U233 bred from Thorium on the previous test). This would enable a self sustaining Thorium breeds U-233, and fissions. Reprocessing is needed to remove fission products, and fresh Thorium is added. But this requires reactors as advanced as the Halden one (reduced moderation water cooled reactors, or in Halden's case, a heavy water boiling reactor which have similar advantages, this type of fuel in a regular reactor fails to breed enough U-233 to keep the cycle going).
But the real problem with any water cooled reactor is costs. Thorium in itself won't make for cheaper reactors (except that it might allow for power upgrades on existing reactors, which allow more energy production for the same investment, but not enough a gain to fundamentally improve the economics of existing nuclear).
The longest living fission products have a 30 year half life, which means in 30 years half of it is gone. Rule of Thumb is one needs to wait 10 half lives before considering the material stable, so 300 years. Regular spent nuclear fuel also has this 30 year half life fission products (Cs and Sr), but also have Plutonium which has this 77000 yr half life, which leads to the statement that it will take a million years to be stable (10 x 77000 yr half lifes), but Plutonium radioactivity is much lower than Cs and Sr.
The critical aspect of Thorium in this sense is some designs could achieve much higher burnup (as much as twice as much of the fuel loaded into the reactor fissions vs conventional uranium reactors), this means that once that fuel is used up, it has twice as much fission products, and it also means it will have a lot more fissile U-233 vs a conventional uranium fuel would have Plutonium.
Think about it like this:
Of 250 tons of mined Uranium:
225 tons become depleted uranium, which is a fairly benign material (could be dumped back into the Uranium mine if needed), but still otherwise could become nuclear fuel using a fast reactor
35 tons become enriched uranium, is manufactured into nuclear fuel
In a typical reactor, one ton of those 35 tons will produces about 1GW-year of electricity, at the same time that fuel will be too saturated with fission products to continue to be used, so it needs to be removed
This results in:
1 ton of fission products (up to 30 year half life)
0.5 tons of U-235 (the good stuff that enrichment enrichs)
0.5 tons of Plutonium (also a nuclear fuel, but not as good as U-235)
33 tons of U-238
So reprocessing this fuel will separate 1 ton of fission products, and re-use 1 ton of fissile nuclear fuel (U-235 + Plutonium)
With a reactor that is 6x more efficient, you'd have 6 tons of fission products, most of the U-235 gets fissioned, and a lot more plutonium is produced. The other advantage is since the fuel is molten in a fluoride formulation, reprocessing is much simpler, since reprocessing needs the fuel also in a fluoride form (no need to remove the Zr cladding and no need to convert Oxide fuel into Fluoride form). This means reprocessing Molten Salt Uranium fuel with 6x higher burnup = reprocessing is about 10x more economical. The problem with reprocessing in the USA today is it's cheaper to simply get fresh fuel (from mined uranium) instead of reprocess it. If reprocessing were 1/10th the cost, then reprocessing would be a cheaper alternative to fresh fuel, and nuclear operators would do it. In most countries nuclear reprocessing is done by govt mandate, typically with total or partial govt funding.
And compare that with Thorium fuel. Since all Thorium is fertile, there is NO enrichment, all of it becomes fuel. Th-232 breeds U-233, which is a better nuclear fuel even than U-235 for thermal spectrum reactors (vs Fast reactors, less than 1% of reactors in the world are fast), reprocessing spend fuel from Thorium/U-233 means just removing the fission products.
The big advantage of the Thor Energy efforts at Halden is they will enable using Thorium in all nuclear reactors in the world, at the cost of continuing with the solid fuel preparation costs (which are higher with Thorium than with Uranium), but the increased burnup, potential reactor uprate, huge reduction in waste production with reprocessing. For instance South Korea right now is reaching a choke point in its nuclear waste storage facilities, because their deal with the USA forbids them from reprocessing.