December 01, 2007
Political Drive For Thorium Nuclear Reactor Development

Some politicians want to push thorium nuclear reactors. They are doing this for fairly parochial reasons. But there are potentially much wider benefits if they manage to kickstart thorium nuclear power.

Senators representing several Western states, including Utah's Orrin Hatch and Senate Majority leader Harry Reid, of Nevada, are working on legislation to promote thorium. They say it's a cleaner-burning fuel for nuclear-power plants, with the potential to cut high-level nuclear-waste volumes in half.

"They're concerned about the spent fuel from nuclear reactors ending up in their states," says Seth Grae, president of thorium-fuel technology developer Thorium Power, based in McLean, VA.

This method of fueling reactors can work with existing reactors modified to use a mix of uranium and thorium fuel rods. Neutrons from Uranium-235 are used to convert Thorium-232 into Uranium-233. The Uranium-233 is fissile (it can break down to release energy to drive electric power generation). The Wikipedia Thorium page says that Thorium as a nuclear fuel requires solving problems related to fuel fabrication and reprocessing.

In theory Thorium delivers a few benefits. First off, the waste is not as difficult to dispose of in part because thorium rods stay in reactors for longer periods of time than uranium rods. So fewer rods come out needing disposal. The greater ease of disposal motivates the US Senators from Western states to support it since they oppose the use of sites in their states (e.g. Yucca Mountain in Nevada) for disposal.

Thorium's fuel cycle also poses less risk for nuclear proliferation. The reduced risk of nuclear proliferation sounds very beneficial as well. The coming decline in world oil production is going to cause a big drive to develop nuclear power around the world. The ability to put thorium reactors into less developed countries would reduce the use of uranium in places which aren't full of peace, love, and understanding.

Combining uranium with thorium would also basically stretch the supply of uranium. Whether we really need to do that is much debated. The Japanese process for uranium extraction from the oceans might make uranium reserves depletion a non-problem. But thorium at least might lower total nuclear fuel costs.

If you are curious about thorium as an energy source Kirk Sorensen writes a web log Thorium Energy dedicated to the topic.

Update: Thorium Power will test thorium in a Russian nuclear reactor in 2010 (PDF format).

Lead test assemblies of thorium fuel are planned to be loaded into one of the VVER-1000 reactors at Kalinin near Moscow in 2010 as part of a multi-year demonstration program, Ernie Kennedy, a member of US company Thorium Power Ltd.’s technical advisory board, told a London conference October 31. He said the idea is to demonstrate the new fuel, which consists of a central “seed” assembly surrounded by a thorium blanket, in a VVER and “then expand to other PWRs and then perhaps BWRs,” for which the thorium fuel design is more difficult.

Thorium Power says thorium as a fuel reduces nuclear proliferation risks in a few ways.

Charles said spent thorium seed-and-blanket fuel would be “very difficult” to reprocess because of gamma radiation, and “wouldn’t be worth it” because the seed assemblies would contain very little fissile material and a lot of minor actinides. In the seed-and-blanket assembly, a central metallic “seed” consisting of either uranium-zirconium or plutonium-zirconium fuel rods is surrounded by a thorium-uranium dioxide blanket.

Kennedy said the thorium in the blanket reduces the proliferation risk of fissile materials in the spent fuel because, under irradiation, the thorium is converted to fissile U-233, which is burned in-situ over the life of the fuel assembly. Also, the thorium fuel cycle leads to the production of only small amounts of plutonium and the isotopic content of that plutonium makes it more unsuitable for weapons than normal reactor-grade plutonium.

For countries that want to consume excess plutonium, plutonium in the seed of the thorium fuel assembly can be burned “about three times faster and at somewhere between a third and half the cost of the mixed-oxide process,” he said, referring to more conventional uranium-plutonium oxide fuel now used in LWRs.

Share |      Randall Parker, 2007 December 01 12:33 PM  Energy Nuclear

David Weisman said at December 1, 2007 2:10 PM:

What? Shouldn't you be denouncing all this unnecesary Thorium nonsense? I mean, there's no problem with waste disposal or proliferation risks as things stand now with non Thorium reactors, is there? Since the problems nuclear plants have now are more related to people who don't understand that and oppose them rather than the price of Uranium, even talking about Thorium is totally unnecessary and promotes pointless alarmism.


K said at December 1, 2007 7:40 PM:

IMO we just don't know yet about thorium. I recall that there is a huge amount of it available but theoretically it isn't very efficient.

I agree with David that nuclear is safe and desirable now. But convincing me won't get any power generated.

Anything promising even safer nuclear should be explored. It appears thorium as a fuel is about to meet the tests of reality. And about time.

Randall Parker said at December 1, 2007 8:42 PM:


David is being sarcastic.

David Weisman,

First off, all energy sources have problems and costs. Some argue that since nuclear power has waste disposal problems we shouldn't use it. But I look at it and think that coal inflicts worse problems on us and wind and solar don't work for base load. So we are better off with nuclear and should welcome technological advances that reduce nuclear's costs.

Proliferation risks: Again, slightly subtle thinking is helpful here. When France and Japan build nukes the proliferation risks don't go up. But when Middle Eastern countries build nukes then, yes, proliferation risks go up. Well, the Middle Eastern countries are going to build nukes (e.g. Egypt wants to). Better to get them on a fuel cycle that lessens the risks.

K said at December 1, 2007 9:29 PM:

I applaud David. The best sarcasim is undetected. I haven't encountered him before and wasn't alert.

Anyway, I am pleased that real testing with thorium will be done.

Nuclear power generation is a political problem not a technical one. Some opponents have painted themselves into a corner. They can never accept reactors as they are built today. Thorium, if it proves out, can be endorsed as a new method, much safer, w/o loss of face.

Paul F. Dietz said at December 1, 2007 9:46 PM:

Shouldn't you be denouncing all this unnecesary Thorium nonsense?

Ok! If thorium-using reactors require reprocessing of fuel elements, then there's little reason to think they'll be economical at current uranium prices. Reprocessing is expensive. If the reactors in effect do their own reprocessing, by online separation of fuel dissolved in molten salts, for example, there are other problems, such as a highly contaminated primary loop.

Thorium might make sense if you use it as an extender in fuel elements that are never reprocessed. IIUC this can extend burnup in CANDU reactors by about 30% (for a given quantity of mined uranium).

Randall Parker said at December 1, 2007 9:54 PM:


I've read figures for uranium rod replacement in the range of every 2 to 3 years versus just once every 9 years for thorium. Whatever then has to be done with the rods gets done to a much smaller volume of thorium rods.

It sounds like there are at least two approaches with thorium in existing reactor designs:

1) Separate thorium and uranium rods.

2) Mix thorium and uranium together into the same rods.

aa2 said at December 2, 2007 12:00 AM:

Randall have you seen Dr. Robert Bussard's talk about inertial electrostatic fusion yet? Seems to be something there imo.

Ken said at December 2, 2007 9:00 AM:


Thorium power Ltd. takes the second approach. Radkowsky came up with a 'seed and blanket' approach with the rods being Pu from decommissioned warhead and the blanket being 90% thorium oxide and 10% enriched uranium (which doesn't seem like "stretching uranium supplies"). In this scheme the seed is discharged every 3 years as it becomes burned out from the very high neutron density given off by U233 fission. This was originally conceived of as a means of Plutonium disposal with energy as a bi-product, which is ironically the reverse of the uranium cycle which was originally conceived of as a means of weapons material production with energy as a bi-product. You actually WANT rapid turn over of this section of the core because that means you are reducing stockpiles of Pu. This method is also estimated to be 3X faster than MOX and you don't have a loop back in the cycle as more plutonium is produced in a MOX burning reactor from the U238 present in the fuel, which then requires another round of reprocessing and burning. MOX also requires a re-engineering of existing reactors, which supposedly the Radkowsky design does not. The blanket, which makes up the majority of the core's mass spends around 9 years in the reactor. The design has been up an running in a research reactor at 1/3 scale for >3 years. There has already been 13 years of research and millions of dollars spent on this project and its coming close to the lead test assembly stage. The second generation development project is the creation of two designs that use ether uranium or reactor waste plutonium in the seed for general commercial use. This has a high potential for export to geopolitically sensitive areas of the world and to countries that don't want to deal with the much more long-lived waste products of the current uranium cycles. It should also appeal to those who want to boost the appearance of not pursuing a nuclear weapons program. I imagine in many countries, plutonium on their territories represents a unwanted security risk as well.

As far as reprocessing, I believe that the blanket part of the core could be stored for a protracted period of time (around 30 years) while the majority of the radio-toxic isotopes decay and then be reprocessed to provide the uranium component for new thorium blanket rods. In this case, a steady build-up of spent thorium fuel rods means a steady build up of future fuel stock. I don't know how much U233 would be present in the spent rods, but it should be an amount worth processing. This also gives time for reprocessing technologies and the thorium fuel and reactor designs to further advance.

Wolf-Dog said at December 2, 2007 2:26 PM:

Too little too late! Just compare how much money we have been wasting in Iraq and Afghanistan, to the ridiculously small amount of money allocated for nuclear energy research... Only a few millions of dollars are being discussed every year. This is tragic.

Randall Parker said at December 2, 2007 4:55 PM:

aa2, My take on all things fusion power related:

1) Plasma physics attracts extremely high IQ minds.

2) Those brilliant minds do not know how to make fusion viable.

3) Who am I to judge? I don't have the technical chops.

A friend dropped out of Stanford's Ph.D. plasma physics track in the 1970s because the scientists there told him they wouldn't solve the problem in his lifetime and that if he wanted to pursue an achievable goal he should switch to another field. But that if he liked research that was interesting with huge problems then stick with it. He went and got a Ph.D. in another field. I think of what he told me when I hear someone claim they found an easy way to do fusion energy.

Janske said at December 2, 2007 5:22 PM:

Well I hold a wait and see attitude. The fusion system in question is approaching the task by other than traditional plasma containment so maybe there's reason to be optimistic. I realize Dietz is vehemently opposed due to his readings which is fine, everyone should have their say if it's reasoned out properly. I'm inclined to see if the Department of Naval research is full of optimists or reasoned thinkers. They did put money into it again so there must be some potential of success. Just about anything has more potential than that monstrosity in France that's got billions pouring into it :)

As far as going the thorium route I support that fully. It's potentially cheaper and may allay the fears of the more moderate anti-nuclear cliques (the extremists of course would never be happy unless we're all living in thatched cottages using water wheels).

Paul F. Dietz said at December 2, 2007 9:29 PM:

I think Bussard's scheme can't work. That opinion is based on no-go results published in the refereed literature. The Bussardites think otherwise, but have not seen fit to publish (in the refereed literature) their refutation of these earlier results. But apparently the internet fan base doesn't need solidly grounded science before firing up the hype machine.

Janske said at December 3, 2007 12:55 AM:

I believe your question about publishing was answered on another board. A board where posters were eulogizing Bussard's passing and you seemed fit enough to stomp in and pick a fight. I also remember that after an individual, professing to be his daughter, posted an explanation you finally ceased and desisted. Perhaps I shouldn't even have brought up the subject but your lack of decorum on that occasion still irritates me to no end.

I know the literature your referring to and have heard the arguments from the other side. Will it work? Damned if I know. Not my area of expertise, just as it isn't your area of expertise. The fact though that you characterize anyone supporting the theory as a "fan base" is telling. I assume the people providing venture capital for the Irvine group's colliding beam (the primary focus of the dissenting information you speak of), and the people holding the checkbook for Naval Research which is funding Bussard's concept must also be fanbois. If either or both systems have a chance of succeeding we should have some information concerning it by late summer next year.

You know, it's fine to have an opposing opinion. I normally consider your various comments well worth reading and usually agree with them. The exception though is this subject about which you're displaying more than a bit of obsessive behavior.

aa2 said at December 3, 2007 1:49 AM:

Jankse I was also thinking military government is different then other government agencies. The military is like a corporation in a free market.. they face real competitors. If a technology has a realistic chance of success.. even if the military doesn't want to do it, the fear is always that a competitor will. And anyway the military seems to be full of optimists. And it certainly is a meritocracy.

I had the exact same thinking as Randall.. fusion is something that maybe people in 2150 can think about. Now after hearing Bussard's breakthroughs I'm thinking its a possibility. Of course the rational way to go about things is build what we actually have in the here and now, while also researching blue skies type of revolutionary technology for in the future.

One nice thing about the world today is that its a big world. There are multiple centers around the world rising which can fund even huge research programs. Different nations are trying different things, such as France with its 77% nuclear power that I like.

Paul F. Dietz said at December 3, 2007 6:33 AM:

A board where posters were eulogizing Bussard's passing and you seemed fit enough to stomp in and pick a fight. I also remember that after an individual, professing to be his daughter, posted an explanation you finally ceased and desisted.

I remember it (assuming this is the same thread) somewhat differently. Proponents used his coffin as a soapbox to continue to promote a scheme that has very little objectively going for it. I eventually stopped posting, but only because I do that when threads get stale, as they quickly do on blogs. I have seen no adequate rebuttals of the technical points I raised, there or elsewhere. I do not recall anyone claiming to be a daughter; I do remember a discussion with Ligon in which the response to my specific technical criticisms eventually devolved to something along the lines of (paraphrasing) "it's complicated and we'll have to wait for results". Uh huh.

You know, it's fine to have an opposing opinion. I normally consider your various comments well worth reading and usually agree with them. The exception though is this subject about which you're displaying more than a bit of obsessive behavior.

Not all opinions are equal. Mine are based in specific technical objections, grounded in the refereed literature. The opposite side appears to be based on hope.

And you don't know me very well, do you? I have a very long internet history of not suffering fools gladly, and I view most of the thundering herd of cheerleaders here (you don't call them obsessive, but I suspect that's just because they're numerous) as being foolish. If I am harping on this subject a lot, it is only because it's a subject (fusion and alternate schemes for it) that has interested me for a long time.

BTW, I don't think the Irvine colliding beam thing will work either, but their scheme does avoid some (but not all) of the no-go results that shoot down a Polywell device using H-11B. And the Irvine people at least have published a paper in the refereed literature attempting to rebut Rider, although I believe the rebuttal is flawed.

Russ Mitchell said at December 3, 2007 1:21 PM:

Hold and wait ain't happening, gents. If you read the fine print of our nuke deal with India... it's thorium-based.

Tim said at December 3, 2007 2:11 PM:

There is no need for nuclear reator development. When there is a sizable resource of accessible geothermal energy about 3000 times the current us consumption.

Brett Bellmore said at December 3, 2007 3:45 PM:

Where would this discussion thread be, so that I can read it?

Janske said at December 3, 2007 5:04 PM:


"I remember it (assuming this is the same thread) somewhat differently. Proponents used his coffin as a soapbox to continue to promote a scheme that has very little objectively going for it."

Define for me the term eulogizing. Normally a eulogy is not defined as an adversarial dismemberment of a deceased individuals efforts. The predominate sentiment of that thread was the hope of success as a testament to Bussard's work. If you consider your actions that day as appropriate decorum then it's very fortunate we're not neighbors. That is the primary reason I'm confronting you. Your "long" posting history has caused you to take yourself a bit to seriously.

I also do not suffer fools gladly. My observation of obsessive behavior is reinforced by your rather cavalier attitude on this subject. I would leave a space below where we could post our respective CV's showing our training and work in the applicable fields of physics except it would remain empty due to neither of us have those credentials. You are, I believe it was mentioned somewhere, in IT or some such. I'm simply an old retired soldier. It is encouraging though that at least some of the subject matter experts take it seriously enough to do the work. Apparently so do some venture capitalists concerning the colliding beam concept, which I might add most of your refutations that you use were directed against beginning in '99 was it? These money sources would have done at least a bit of due diligence and would know of the opposing views. I have to assume that the Irvine group had plausible arguments for persuading these backers to write checks. Much the same can be said for the Bussard concept.

There's disagreement between individuals who "do" have at least some of the requirements for an appropriate CV. We are onlookers expressing opinions. An opinion plus $5 will buy you a large Lotte. Being argumentative while posting at some blog is harmless. Displaying an overflowing hubris is more than a bit unseemly.

I rather hope that one of the potentials such as levitated di-pole, reverse field, polywell, colliding beam etc. proves correct since I have little faith in ITER. Even if they someday succeed ITER may very well be impractical to commercialize though at least plasma physics will have been advanced. Our civilization could prosper with a well managed fission economy. The potential though of practical fusion would up the future outlooks tremendously. Some people do get over excited and verge into boosterism. Other's slip into negativism and begin a full assault out of reflex. Both should take a deep breath and act sensible.

I've expressed my sentiments to the extent I desire on this issue and will no longer consume Mr. Parker's bandwith.

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