Guest Post by David Archibald
There is a rich tradition of rational weathermen taking an interest in the potential of thorium-based nuclear power.
Witness this video made by John Coleman:
The irrational have also taken an interest in thorium’s potential. A warmer journalist by the name of Richard Martin has written a book entitled “Super Fuel” published on 8th May, 2012. Like all warmers, his grip on reality is a bit weak. One example of this is on page 55 where he states “the container ship Altona, bound for China and carrying a load of 770,000 tons of uranium concentrate.” The biggest ship on the planet carries some 500,000 tonnes and the world yellowcake market is about 80,000 tonnes per annum. Perhaps he meant 770,000 lbs instead of tons, but nobody else in the editing and publishing chain picked up the mistake either.
A second howler is on page 195 which states “After the Fukushima-Daiichi accident, there was a brief run on supplies of iodine-131. An isotope of iodine produced in specialised reactors, iodine-131 is used to prevent thyroid cancer from radiation exposure.” What he meant was that there was panic buying of potassium iodide which is used to prevent thyroid cancer from iodine-131. For those interested in buying potassium iodide before the next nuclear scare instead of after it, the motherlode is Nasco in Wisconsin who will sell you half kilo of granules for $57.25. That’s enough to treat 360 people.
There is also the warmers’ naïve world view on display. For example, on page 238 he predicts that “Enhanced energy security, and the economic power and diplomatic prestige that come with it, allow India to reach a lasting détente with its perennial foe, Pakistan.” Haste is also evident – on page 132, Alvin Weinberg is referred to as “Weinberger”.
But I wouldn’t be mentioning the book at all if it wasn’t also useful and interesting. A large part of it is taken with recounting the history of two of the main protagonists of the early years of the nuclear age: Alvin Weinberg and Hyman Rickover. Weinberg was the earliest promoter of the molten salter reactor burning thorium. The coup de grace to the thorium programme was delivered by Milton Shaw when he was director of the reactor research and development at the Atomic Energy Commission. The world has been side-tracked on the dead end of uranium-burning light water reactors ever since. While not in the same league of storytelling as “The Making of the Atomic Bomb” by Richard Rhodes, “Super Fuel” gets the reader up to speed on thorium’s history quickly and relatively painlessly.
June 2012
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I have been avid readers of both of WUWT and Kirk Sorrenson’s websites for many years. It is without a doubt that we are on the cusp of huge changes in the way we do business in this country and energy production. Not only will it allow current business enterprises to flourish, but will allow a huge new growth among those that don’t have the resources of energy production today. Through the use of thorium and Liquid Floride Thorium Reactors we will see a transformation never seen before in the world. IIt will create such an enormous benefit to those that can’t afford importing energy production and will bend the proverty scale back so much the impediment for a decent and respectable life style will a norm. Why would we not choose that choice? I know why. Tyranny!
RE: clipe: (June 9, 2012 at 2:00 pm)
” arrived in Canada as a twelve-year-old boy in 1967. CANDU was a hot topic.
According to Kirk Sorensen, (see http://www.youtube.com/watch?v=gbCW1-PVteU) CANDU uses non-neutron-absorbent heavy water coolant in a standard, high-pressure, water-cooled reactor design to increase the efficiency to the point where a lower (cheaper) grade of uranium can be used.
Thus, I regard CANDU as a design option for today’s existing uranium 235 burning reactors, where the uranium fuel enrichment operation is replaced by a coolant deuterium enrichment process.
The thorium reactors under discussion have their fuel dissolved in ambient pressure, high temperature liquid salts that continuously recycle the fissile material. The CANDU principle does not apply because thorium does not need to be enriched and there is *no* water in the nuclear reaction chamber.
The potential advantages of using thorium in molten salt reactors include safe, non-explosive, low-pressure design, abundant sources of fuel, and minimal production of dangerous transuranic nuclear waste.
The primary radioactive waste produced is in the form of fission fragments that rapidly decay in a few hundred years, primarily by unstable excess neutrons shooting off an electron to become a proton. Today’s reactors produce waste rich in fissile transuranics that will have to be managed for tens of thousands of years.
Just for reference, here is an eight minute, Kirk Sorensen video on the nature of Nuclear Waste:
LFTR vs Nuclear Waste – Plutonium, americium, curium (transuranics)
can be fissioned / disposed
“Uploaded by thoriumremix on Oct 7, 2011”
41 likes, 1 dislike; 4,901 Views; 7:48 min
“Sign the petition! http://ThoriumPetition.com – LFTR does not produce transuranic waste. It burns up essentially all of the fuel because we don’t remove fuel from the reactor until it’s a fission product.
“It is these transuranics like plutonium, americium & curium which present the biggest challenge to nuclear waste disposal. They have moderate half-lives (neither decay quickly nor low levels of radiation) and have complicated decay chains.
“All of today’s pressurized water reactors (every commercial reactor operating in North America) use less than 1% of the energy stored in the nuclear fuel. This is why the spent fuel rods are difficult to manage. LFTR can consume almost all of its fuel. This big increase in efficiency means less nuclear waste to deal with.
“And because LFTR (Liquid Fluoride Thorium Reactor) uses LIQUID fuel, it is far easier to partition the ‘waste’ to extract valuable by-products, such as medical isotopes for cancer treatment.”
BTW, the principle that a small amount of radioactive exposure may actually be beneficial is known as ‘hormesis.’
RE: Solid Thorium Reactor Cores
One thing to keep in mind is that thorium is not fissile on its own. It *must* be placed where it will be struck by neutrons. Thorium absorbs neutrons. Each neutron absorbed changes a thorium 232 atom to thorium 233, a more unstable isotope. That quickly changes to protactinium 233, also an unstable non-fissile isotope. In the molten salt reactor, the protactinium 233 is removed from the reaction chamber before absorption of another neutron can knock it up to protactinium 234.
The protactinium 233 eventually shoots out another electron and becomes uranium 233, which is fissile. This fissile uranium 233 is then returned to the reaction chamber. When a uranium 233 nucleus is struck by a neutron, it will fission and in that process give off, on average, slightly more than two neutrons. That yields one neutron to shatter another uranium 233 nucleus and one more to convert another thorium 232 nucleus to thorium 233.
The fluid state reactor core allows continuous chemical processing of the thorium/protactinium fluid and the fissile uranium fluid. Solid state thorium has been described as very difficult to process as required to continuously remove the protactinium 233 from the neutron flow. However, one might be able to slightly improve the efficiency of high-pressure, light water or heavy water (CANDU) reactors by including some thorium in the mix, given that these reactors only consume a small fraction of the fissile material in the fuel rods. Dr. David LeBlanc says that the real advantage is the fluid state reactor concept that can consume almost 100 percent of the fissile material.
As far as I can tell, the main factor which has stood in the way of molten salt reactors is what Richard Martin describes as ‘technological lock-in.’ Once the design of a working nuclear reactor was accomplished, it became the standard and all nuclear technology since has been required to be ‘compatible’ with that design. It, like the ‘IBM PC,’ became the industry standard, despite the fact that its original designer, Alvin M. Weinberg, considered that design potentially impractical and unsafe for use as a public power generation reactor.
From Spector on June 10, 2012 at 12:24 am:
Thus he is wrong except in the broadest sense possible. As seen here, the heavy water acting as moderator is in the calandria, the coolant in the pressure tubes may be either heavy or light water. There is no large pressure vessel containing the core. The pressure tubes are contained within calandria tubes with CO2 as an insulator between them, the low-pressure calandria water is kept cool. There is on-power refueling where fuel bundles are swapped out while running, no reactor shutdown needed. And from the beginning they were designed for easy refurbishment of the core, including nice touches like how the pressure tubes can be removed for inspection and replacement at any time.
They are far from “a standard, high-pressure, water-cooled reactor design”.
This “design option” also allows for a wide range of fuel choices that conventional enriched uranium burning reactors can’t use. That alone makes it radically different. And it’s not a “coolant deuterium enrichment process” but improved neutron economy, allowing the use of less-reactive fuel.
What is this “CANDU principle” you speak of? The ‘continuous recycling’ involves integral fuel reprocessing. Which an additional unspoken burden on LFTR development. We don’t do fuel reprocessing in the US. How do you expect this “backdoor” reprocessing to be allowed? On the same site you’d have both a nuclear power plant and a chemical plant, increasing approval and permitting requirements. And dramatically increasing the public acceptance issues. A nuke plant is now becoming marginally acceptable in the US due to pressing energy and environmental issues. But to also get in a chemical plant using fluorine as well?
The reactor end may be low pressure, but the heat is still used to generate high-pressure gas to drive a turbine, normally water vapor (steam). So those dangers are still present.
CANDU’s are so efficient there’s no economic incentive to recycle fuel. How can required recycling be an advantage with LFTR’s? The “waste” from light water reactors is fuel for CANDU’s, reducing the waste issue. Canada has well thought out plans to deal with their waste by Deep Geological Disposal (DGD), as verified by studying natural undisturbed deposits of nuclear materials. Tens of thousands of years shouldn’t be an issue, but it’s not strictly necessary anyway. After only 500 years the radiation from a CANDU fuel bundle is minimal. The one credible mechanism for release of the disposed waste to the surface is by ground water, and after several hundred years the relative toxicity is equivalent to natural uranium ore and other deposits.
Plus CANDU’s can burn up the long-lived actinides anyway.
In any case, it’s an unfair comparison. LFTR’s have reprocessing built in, you’re comparing to reactors without reprocessing. Run the LWR “spent” fuel through CANDU’s, reprocess used CANDU fuel and send the actinides back through, you’d have similar long-term waste amounts.
From Spector on June 10, 2012 at 6:15 am:
Technically speaking, a full LFTR power plant has never been built. The much-vaunted Oak Ridge National Laboratory Molten-Salt Reactor Experiment (MSRE) was proof-of-concept with the produced heat shed to the atmosphere, didn’t have the heat-to-electricity part. And it “simulated” using thorium, never actually did use any.
Even then, there were problems. The “exotic” alloy Hastelloy-N was selected.
For “adequate life” considerations, the experiment only ran about 4-5 years, and “operated for the equivalent of about 1.5 years of full power operation”.
Among the Results:
Thus material selection is crucial for a LFTR to get a thirty-year lifespan. Meanwhile the planned-from-the-start relatively easy core refurbishment of CANDU’s already makes 50 year lifespans obtainable, using materials that are much-less exotic.
And to mention it, while talking safety, what happens in the worst-case scenario of a complete loss of power? CANDU’s have automatic shutdown from control rods held against gravity by electromagnets, they’ll quickly drop into the low-pressure calandria, which is filled with the cool moderator water to absorb the residual heat, etc. Newer light water reactors also can handle such events with designs incorporating coolant water stored above the reactor that’ll automatically keep the core flooded, etc.
But a molten salt reactor? First assume the reaction does shut down. Then the salts cool down and solidify, aka “freeze”. Then you have a lot of expensive plumbing clogged with solid radioactive salts. It’d take lots of careful heating to get that plant up and running. Water-cooled reactors are simpler to restart.
Yet the engineering problems are only a part of the most important obstacle blocking molten salt reactors, and it’s not “technological lock-in”.
We don’t need them.
We have proven technology that works just as good with less hassle. Uranium is plentiful, we can burn thorium without molten salt reactors. Worried about long-lived waste and long-term storage? Use CANDU’s and reprocess fuel. Kirk Sorensen wants to develop small modular reactors. There are many designs being worked on using far more conventional designs, and even simplified by using natural convection instead of pumps for coolant circulation.
Although this Forbes article argues that cheap natural gas has killed the market for SMR’s. Natural gas would have to be about four times more expensive than currently, or likewise made much more expensive with a “carbon” tax, for SMR’s to compete. Of course there are many places in the world, including in the US, without access to that cheap gas, without the sources or the pipelines, where those more-conventional SMR’s will work quite well.
So why do we have to bother with unproven complex complicated LFTR’s at all?
RE: kadaka (KD Knoebel):(June 10, 2012 at 10:26 pm)
A few points:
I believe that the complicated three-stage breeding process required to burn thorium makes it difficult for use in non-fluid core reactors. In his talk, (http://www.youtube.com/watch?v=370srr67Bnk) Dr. David LeBlanc says that designing a solid state thorium reactor would be very hard. CANDU may have many advantages, but it seems unlikely that burning thorium as a single fuel would be one of them.
I believe President Reagan lifted the ban on nuclear reprocessing imposed by the Carter Administration and I have no indication that any such ban has been reimposed since. In any case, I think the issue here involves the frequent transport of spent and reprocessed fuel rods and the risk of accidents in process or in transit and the risk of theft and proliferation. With continuous recycling, break-even breeding, no fissile material leaves the reactor
The liquid fuel concept allows continuous integrated reprocessing without shipping the fuel off site or changing from the molten state. From what I hear, most of the processes required are standard chemical industry practice. The Oak Ridge demonstration unit was walk-away-safe and ran for several years, as far as I know, without incident. That project appears to have been shut-down to focus on what the Nixon Administration saw as the great hope for the future, the more conventional liquid sodium cooled, uranium/plutonium breeder reactor. (see: http://www.youtube.com/watch?v=bbyr7jZOllI)
While it is true that there may be a high-pressure steam turbine to generate electricity, there are multiple options in this regard and the standard designs include a ‘clean salt’ buffer unit so that two failures are required before high pressure could reach the core. I do suspect that the complexities associated with all this ancillary equipment may make large installations more practical than small modular units.
Keeping the fissile material in the core until it becomes a short-lived fission fragment largely eliminates the need for long-term waste disposal sites. Short-term (300-year) waste holding sites are another issue.
The primary design challenge that I see is the qualification of the design of the barrier between the two fluids, which must remain stable as neutrons are flowing through it.
RE: kadaka (KD Knoebel): (June 11, 2012 at 2:28 am)
“So why do we have to bother with unproven complex complicated LFTR’s at all?
I look at that technology as one potential successor energy source after all forms of cheap carbon energy have been exhausted. It appears that we have already taken out all the easily obtainable petroleum in a mere hundred years. Now we are shifting gears to go after more difficult and lower grade sources. So far, there seems to be little hope that any current conventional nuclear technology could be expanded to the scale required to fully replace carbon based chemical energy as a solution for all time in the future.
As for the much heralded green energy, I do not believe it could support any more than a small fraction of today’s population after petroleum and other critical technical resources have been depleted due to the surface area per person required to collect it..
I think we need to prove, once and for all, that LFTR’s *cannot* be made to work well before we might be faced with a ‘great world population decimation period’ due to lack of energy. It may take well on the order of half a century before LFTR technology could be expanded from pilot plant to common use, based on the time it took steam to replace sail on ships.
So far, LFTR is the only potential nuclear technology I know of that fully consumes the toxic transuranic waste. The continuous accumulation and incidental releases of this persistent waste makes the long-term, large-scale viability of other nuclear technologies questionable. The unique low-pressure core design should reduce the likelihood of dispersive explosions. At this stage, the cost of further development should be minimal.
From Spector on June 11, 2012 at 2:49 am:
And why would thorium as a single fuel be so advantageous?
(BTW, I’m on dial-up so I ignore video links.)
See “CANDU Advanced Fuels and Fuel Cycles“, by P.G. Boczar et al (2002). You could have a long-term fuel cycle using only thorium as the inputed material, that requires recycling the U-233, which is problematic as “the daughter products of U-232 and Th-228 emit hard gammas”. CANDU-only would be Th/U-233 fuel, otherwise fast breeder reactors supply U-233 for CANDU’s.
But there are economical near-term ways.
First off, thorium dioxide (aka thoria in the paper) is used. “It is produced mainly as a by-product of lanthanide and uranium production.[1] Thorianite is the name of the mineralogical form of thorium dioxide.” It has better physical characteristics than uranium dioxide.
In a CANDU, thoria is burned with slightly-enriched uranium (SEU). It takes much longer to burn up the thorium than the SEU. From the paper:
First one, just leave the thorium in the reactor until the U-233 is consumed. Second one, there’s a timing difference so store the fuel elements that still have some dregs left.
Doesn’t seem difficult at all.
See this 2009 Nature editorial, Adieu to nuclear recycling: President Barack Obama should be applauded for his decision to scrap commercial reprocessing. President George W. Bush was trying to restart US commercial reprocessing, wanted a demonstration plant, an environmental review was underway. Obama squelched that. He has deigned to allow research on improving reprocessing, limited to “basic science”.
Hail to the Chief.
Nah, the primary issue is money. This is gathered from the long convoluted Wikipedia nuclear reprocessing entry. In 2011 the Japanese, who already have reprocessing, calculated the costs at about twice that of direct geological disposal. This article from the Bulletin of the Atomic Scientists, summarizing a study, gives these numbers for commonly used above-ground dry cask storage:
Plus normal reprocessing is messy, involving many chemicals and subsequent disposal. Reprocessing was originally developed for extracting bomb materials. As for commercial use:
I’m actually reconsidering believing reprocessing reduces long-term storage concerns, based on this from the article:
Reprocessing is not needed from an economic standpoint, new fuel is cheaper and disposal is also cheaper. The exchange is made from handling solid spent fuel to dealing with liquid wastes. Solid is much better for both above ground and deep geological storage.
From the nuclear reprocessing entry, describing Pyroprocessing (high temperature) methods, specifically Fluoride volatility:
The liquid fuel concept introduces an additional large risk of chemical explosions. Read the bottom of the Wikipedia entry on the Oak Ridge MSRE, “Decommisioning”. The stored salts had a dangerous buildup of fluorine gas. The resulting final cleanup was a nightmare.
So you haven’t read either the Operation or Results sections of the MSRE entry?
What does that have to do with the “standard” dangers of a pressurized water system, magnified when using supercritical steam?
Actually we currently don’t need long-term storage, to be technical about it. Just dry cask storage of the solid fuel as the radioactivity greatly diminishes. Then, several hundred years from now, reprocess with the less-messy methods developed in the meanwhile, burn up the long-lived stuff in reactors then.
Although as James Cameron found in the Mariana Trench, the deep ocean has virtual dead zones. Given the great reduction in radioactivity after only 100 or just 50 years, dilution rates and what is already in sea water (it is almost economical to extract uranium from it), and how long it takes such deep water to circulate, the deepest depths will be all the long-term “storage” we’ll need. Let the solid fuel cool off up here for a bit, then carefully dump deep.
In that case you’re missing a whole lot of important things that must also be solved.
From Spector on June 11, 2012 at 5:28 pm:
Pessimistic much? There remains lots of liquid petroleum to extract, with improving removal technologies, as well as our recent natural gas finds. We have well over a hundred years left. And that’s without considering the reserves of coal, convertible to liquid fuels.
We’re in a technology hole for a bit. We need to develop better more-efficient energy storage systems, which is progressing. Solar cells are getting better, reducing area requirements. As our understanding of genetic engineering increases, we’ll be developing micro-critters that live on sunlight and excrete the liquid fuels we need. There are many things underway to supply us with lots more of dependable renewable energy in the decades to come.
Conservation efforts continue. We can build passive houses requiring no heating, likely no cooling. Geothermal heat pumps economically reduce energy demands for heating and cooling with quick payback times. Appliances and vehicles are more efficient. Heck, people now do on smartphones and iPads what they used to do on P4 PC’s which qualify as space heaters.
So as time goes on we need less energy. The major bugaboo of the “running out of energy” crowd is developing nations using more energy, and we can share our high-efficiency tech with them. So the “crisis” is much less than advertised, the crunch point much further in the future.
As above, and it has the potential someday. Although I don’t expect much of “Green energy” anytime soon.
I think we need more nuke plants, period. LFTR has no demonstrable advantage over proven existing CANDU technology. We can have all the energy we need NOW, affordably.
As seen, not an issue.
Likewise for CANDU’s. The fuel is sealed away from the coolant water, the coolant is in high pressure tubes, surrounded by calandria tubes, with the surrounding calandria moderator being low-pressure. Makes a explosive-type dispersion of radioactive materials nigh-impossible.
Although the LFTR has to deal with highly-reactive potentially-explosive fluorine gas…
Ah, if I had a dollar for every time a raw unproven technology just needed “…a little more money to get finished, then it’ll revolutionize EVERYTHING!”
RE: kadaka (KD Knoebel):June 12, 2012 at 7:58 pm
“There remains lots of liquid petroleum to extract, with improving removal technologies, as well as our recent natural gas finds. We have well over a hundred years left. And that’s without considering the reserves of coal, convertible to liquid fuels.
And after that is all used up and if we have refused to develop any real sustainable source of concentrated energy, the ‘Olduvai Theory’ kicks in and its back to the stone age. How big a farm are you going to need so that you can grow all your own food and *all* the biofuel you need for heating and transportation including your share for aircraft and marine transportation. Assume you have to produce all your own fertilizer. To date, despite massive government subsidies, wind and solar power only seem to meet about one percent of our power usage. Less power means less people. I think it may take a ruthless worldwide application of the China ‘One-Child’ policy for well over a century to make ‘Green Energy’ viable.
“We’re in a technology hole for a bit. We need to develop better more-efficient energy storage systems…
I do not think you can store what you do not have. Yes, administration and petroleum executives are saying that carbon energy from unconventional sources should be sufficient for decades to come. After that?
“Although the LFTR has to deal with highly-reactive potentially-explosive fluorine gas…”
I am given to understand that this is a standard chemical industry practice. Fluorine is not explosive (shock-sensitive) on its own. It is potentially very corrosive, but the impression that I get is that it is quite safe if properly contained.
“‘(…) At this stage, the cost of further development should be minimal.’
“Ah, if I had a dollar for every time a raw unproven technology just needed ‘…a little more money to get finished, then it’ll revolutionize EVERYTHING!'”
At this experimental model stage, I expect costs to be low as compared with building public power plants. It does have the advantage of being partially demonstrated. It was the brainchild of the inventor of the current reactor technology in use. During the Nixon-Ford Administrations, they were spending about five million dollars a year on LFTR development and about five hundred million dollars a year on the Liquid Metal Fast Breeder Reactor project. It may be that nuclear technology got off on the wrong foot with a ‘Quick and Dirty’ solution for a wartime emergency.
Your comments may be valid reasons for not using back-of-the-envelope, computer model LFTR designs for building public power stations. Any such technology will have to be thoroughly proved before it reaches that stage. If the Administration carbon energy estimates are valid, then we should have plenty of time to do this. Some professional ‘Peak Oil’ speakers are saying that the current recession is the first stage of a global energy depletion crisis.
(BTW, you might check with your phone company to see if they offer DSL service.)
One more reference:
Here is a Link to a recent University of Tennessee, Department of Nuclear Engineering, webcast entitled:
Design Fundamentals of Molten Salt Reactors
Speaker: Dr. David LeBlanc
Formerly of Carleton University Physics Department, Ottawa
Canada
Currently Founder, Ottawa Valley Research Associates Ltd.
Ottawa Ontario
2/1/2012 1:30 PM Est Length: 01:01:47
http://160.36.161.128/UTK/Viewer/?peid=811fb3c7c7714c93a7954874bad331f5