Thorium shines brightly at ANS Winter Meeting

by Will Davis

I have generally been quite a skeptic about thorium as a source of nuclear fuel. Although I know that thorium was tried in the fuel at two very early commercial power reactors in the United States (Elk River, and Indian Point-1), the idea did not take off. The proposals to use thorium in fluid fuel reactors were far less successful, with none moving beyond the prototype stage. Even given the low success rate, it still remains that the use of thorium is promising.

Thorium itself isn’t fissile, because it can’t itself be split to produce energy.  However, if it is bombarded by neutrons then after a decay process it produces a fissionable isotope of uranium.  So, it is called “fertile” rather than “fissile,”  and it is fairly abundant.  There are many millions of metric tons of it around, and it’s not being used for much.

So today, at the ANS 2014 Winter Meeting, I attended the “Thorium Resources, Recovery, Fuels and Fuel Cycles” session in order to see for myself what the cutting-edge thinking might be on using this apparently abundant, but now-all-but-abandoned, nuclear fuel.  The efforts and papers put forth were brilliant, and my view has changed.

The leadoff paper, Thorium Recovery from Rare Earth Element Deposits in the US (Bradley Van Gosen, Steven Krahn, Timothy Ault) first showed us that thorium is very abundant right here in the United States. There are in fact several operations underway right now that can supply it, and that is because thorium is found in the same place where rare earth elements are found.  Thorium is tossed aside as a radioactive nuisance.   According to the paper’s authors, since the material is already being pulled from the ground, and if and when a thorium fuel cycle for nuclear reactors develops, then it can piggyback on the existing rare earth mining operations.  That is a concept that could significantly reduce the capital cost of the fuel cycle.  Furthermore, if the thorium is recovered from mine tailings already dumped, it can help toward what would normally be considered remediation of a mining site.  In other words, what was once perceived as hazardous waste cleanup, would still be viewed as hazardous, but also as a fuel source.

The presentation detailed a number of mining operations, both underway and planned in the US, from which thorium could be obtained if required.  However, it noted that major hurdles face this particular prospect.  For example, the present thorium market is small, and there is zero market for fuel; no government subsidies exist either.  No present facility exists to separate the thorium from the mine tailings; if one did, it would need complicated permitting to stockpile concentrated radioactive material.

These observations made the next presentation all the more important.  “Environmental Impact of Thorium Recovery from Titanium Mining in North America” was delivered next, out of order due to a schedule problem (authored by Timothy Ault, Steven Krahn, Allen Croff, Raymond Wimer).  It pointed out that there is an enormous demand for titanium worldwide, far higher than for rare earths (primarily in white paints) and that where you find titanium, you also find thorium.  In fact, there are dozens of possible titanium (and thorium) mining sites in the US Piedmont Region, beyond the ten or so already operating there.  While the process to separate the thorium from the basic ore would require very large amounts of not only water, but chemicals too, it requires no new materials or processes to be developed that aren’t already in existence. Further, the cost of the process could be driven down if other rare earths essentially sloughed off from this process were sold as commodities.  Thus, the production of thorium from already existing titanium mining is far more attractive than simply finding other ores in the ground and starting a mine from scratch or even remediating rare earth mine tailings.  This essentially moves that first step of the thorium fuel process from the “where, and how” phase to the “here, and here’s how” phase.

In fairness the paper’s authors did detail that the thorium fuel process done this way does have a relatively high radiation dose rate — primarily at the first step where the original ore, called Monazite, is broken down to extract the thorium.  This is because of radioactive Radium-228, which then follows the rare earths through the process.  However, titanium mines here and in Canada already have some processing facilities nearby (although not for nuclear fuel) and have very sufficient transportation infrastructure.  After hearing these arguments, I myself became convinced that thorium might not be that hard to come by after all as a fuel source, and we know how to deal with radioactive materials quite well enough.  One person at the session did speak up and point out that the more or less mainstream thorium messaging constantly points out that it’s about four times more plentiful than uranium, but that this messaging ignores the fact that thorium is also distributed exceedingly sparsely around the world in small concentrations over large areas.  This makes economic recovery of thorium as a fuel a problem, unless you piggyback the process on something already existing, such as mining titanium.

The next paper is at the ANS Winter Meeting session is what really convinced me that this material could actually be used in commercial nuclear fuel, in my lifetime.  Saleem Drera of Thor Energy (a small company of 20 people) delivered a paper on his company’s efforts to develop commercial nuclear fuel, already well underway, which uses thorium and which can be burned in, and licensed in, present light water reactors.

Thor Energy is already testing fuel pellets of a number of designs in the Halden Research Reactor in Norway. The company’s theory is that the introduction of thorium should be “evolutionary, not revolutionary” and should start with the present design of reactors (both boiling water reactors and pressurized water reactors) that will be the mainstay of commercial nuclear power worldwide for at least the rest of the 21st century. To that end, it’s already testing fuel pellets made in its own small lab setup in the Halden Research Reactor in Norway, with excellent results. The company feels that its fuel design could actually allow any reactor in which it is used to receive a power uprate. That is an important point for a utility trying out a new fuel, since the profit margin will be higher. The company’s second run of test fuel pins will be put in the same reactor in 2015. A good deal of the presentation was given to the actual process for manufacturing the fuel, but what is important is that right now we have fuel pins that will work in conventional existing reactors under test.

The final paper presented at the meeting was written by Gonghoon Bae and Ser Gi Hong of Kyung Hee University, South Korea. It was an exceedingly technical review of a new, small, light water reactor core design that can burn what we call TRU or transuranic materials. These are the worst of the materials in spent nuclear fuels, and there have been many attempts over the years to develop reactors that can burn them up. This South Korean group has developed a small (308 MW thermal) reactor, a light water-cooled moderated reactor. It uses a special, graphite-stainless steel neutron reflector and specially developed fuel, including thorium, that can actually burn up a very high percentage of TRU material. The reactor is planned to operate on a four and a half year fuel cycle, and can burn up 25 percent of the transuranics inserted into the core and/or generated in it during operation; part of the fuel includes reprocessed TRU material.

South Korea, however, is now reaching a choke point when it comes to storing spent nuclear fuel. Currently it is working on building a small, light water-cooled and moderated and partly thorium-fueled reactor that can burn up the waste.

I walked out of that session convinced that I need to keep an eye on all of these development tracks. I was enthralled by the enthusiasm of those in the room presenting, and the competence of the questions from the audience. Not only was this one of the best technical sessions I’ve seen at any ANS meeting, it left me changed; I can see a way out for thorium now.


SavannahWillinControlRoomWill Davis is the Communications Director for the N/S Savannah Association, Inc. where he also serves as historian, newsletter editor and member of the board of directors. Davis has recently been engaged by the Global America Business Institute as a consultant. He is also a consultant to, and writer for, the American Nuclear Society; an active ANS member, he is serving on the ANS Communications Committee 2013–2016. In addition, he is a contributing author for Fuel Cycle Week, and writes his own popular blog Atomic Power Review. Davis is a former US Navy reactor operator, qualified on S8G and S5W plants.



About Will Davis

Will Davis is the Communications Director for the N/S Savannah Association, Inc. where he also serves as historian, newsletter editor and member of the board of directors. Davis has recently been engaged by the Global America Business Institute as a consultant. He is also a consultant to, and writer for, the American Nuclear Society; an active ANS member, he is serving on the ANS Communications Committee 2013–2016. In addition, he is a contributing author for Fuel Cycle Week, and writes his own popular blog Atomic Power Review. Davis is a former US Navy reactor operator, qualified on S8G and S5W plants.

32 thoughts on “Thorium shines brightly at ANS Winter Meeting

  1. David Silverman - Perth Web Designer

    Thank you Mr AtomikRabbit.

    I appreciate you taking the time to supply the reading sources.

    On the B-36, indeed you are correct.
    Curiously there were two propulsion systems under development. Open and closed cycle.
    The russians apparently did flights with an open cycle reactor with the crews being beyond child bearing age. I understand that the crews sadly died early deaths.

    Back on B-36’s…
    There is an interesting tale of a broken arrow in British Columbia…
    Theories vary on whether the device was dropped off shore or recovered at the crash site.

    The history of the atomic age is facinating yet largely unknown beyond industry and people like myself…

    Thank you all for feeding me with so much rich information.

  2. Atomikrabbit

    To our Aussie friends who think no one Down Under is discussing nuclear energy in a positive way, may I direct you to some excellent bloggers: Oscar Archer at, Dr. Barry Brooks of, and Ben Heard of

  3. David Silverman - Perth Web Designer

    Very much appreciate such an interesting article and thought provoking set of comments.

    I am not qualified in this field, however follow the subject of Thorium and MSR closely, purely out of interest.
    I have absorbed many hundreds of documentaries and articles on all things nuclear and yet here in Australia we only has a token medical isotope reactor, traded for rights to use Australia as a nuclear proving ground.

    I admire the wisdom exchanged here, on Thorium and wanted to thank both the Author and discussion participants, for a dispasionate exploration of this topic. A refreshing change from the dumbed down hype up mainstream media. The revelation forr myself was seperation of Thorium from other rare earths and the inherrant difficulties.

    I’d like to read more if there is scope to add further articles on this topic in the future.

    Either way, thank you !

  4. John ONeill

    ‘Its half-life is about that of the age of the universe’ ( Robert Hargraves )
    No – of the earth.

  5. Bret

    Check out this video where several of the remaining researchers who worked on the ORNL MSRE were met with for dinner.

    They indicate the problems were primarily political, and while technical issues did occur, they were not seen as insurmountable.

    Paraphrased from Shaw: Thou shalt stop (MSRE), now.

  6. Tony Carden

    Thank you Will for pointing out the facts in relation to an MSR powering a plane ( I did some further research) and I also take your point about the difference between a prototype and a commercial operation. I am also grateful to Stephen DuVal and The ENGINEER POET. I now appreciate that there is a certain amount of Spin going on in relation to MSR’s and Thorium. I guess only time will tell.
    In Australia no one discusses Nuclear Energy at all or at least not in Public. I would be happy for any proven nuclear technology to be commissioned here.
    Nuclear Power is the Elephant in the room. We won’t even entertain the idea of Nuclear Submarines.

  7. Engineer-Poet

    Actually, MSRE was specced to run at 10 MW(th), but erroneous heat sink calculations wound up limiting it to 7.4 MW.

    The breeding blanket was omitted to reduce cost, but neutron flux measurements were made to verify that a breeder was feasible.

    The tellurium cracking problem was found, and a small change to the formulation of Hastelloy-N was made to fix it.

  8. Stephen DuVal

    MSRE was an experiment. It was 8MWth. It did not produce electricity. It did not convert Th232 to U233. Most of the time it ran on U235. Flibe (66% LiF- 34%BeF2) was the coolant. It operated at 545-580C. It was a thermal reactor with graphite as the moderator. It requires an intermediate loop to deal with tritium produced by fission of Li and Be. Little corrosion of intermediate loop with clean salts (no uranium, actinides (includes Th), or fission products).
    MSRE design started in summer 1960.
    MSRE construction started in 1962.
    reactor went critical in June 1965.
    briefly at full power in June 1966.
    Dec 66 reliable operation, 30 days at full power.
    Operated using U235 at full power for 15 months (Jan 67 to Mar 68) to perform experiments.
    U235 was removed from the salt in 4 days using fluoride volatility process and U233 added.
    Operated using U233 for five months (Jan 69 to May 69), first time U233 used as reactor fuel.
    Operated for 7 months (June 1969 to Dec 1969) performing experiments, including xenon stripping, fission product deposition, tritium behavior, and plutonium additions.
    Dec 1969, MSRE terminated.

  9. Brian Mays

    Sorry, molten-salt fanboys, but Will is right.

    The MSRE was not a prototype. As the name indicates, it was an “experiment.” The one thing that it didn’t do, which is crucial for any reactor design claiming to run on a thorium fuel cycle, is produce its own fissile fuel from thorium. The scope of the experiment was much smaller and was intended to gather valuable information on the core dynamics. It was a successful experiment and testing platform; it was not a successful demonstration that could qualify as a genuine prototype.

    Will is also correct that both Peach Bottom 1 and Fort St. Vrain used a thorium fuel cycle. They used a thorium/highly-enriched-uranium combination, however, which I don’t think is being proposed to be used in a commercial reactor any time soon.

  10. Will Davis Post author

    Shawn Disney: It’s the NRC’s job to review, and license if safe, facilities and procedures which are submitted to it. I will take a look around the NRC website and see what actions are pending in front of the commission on licensing facilities using thorium.

    Also, I’ve never actually seen anyone in the industry refer to anything as “foolproof.” That’s often mistaken as the meaning when people do unfortunately use the term “failsafe.” Do you have a link to any industry reports on that fuel pellet testing?

  11. Will Davis Post author

    Sorry, but thorium fuel was used in Elk River’s first core, and in Indian Point’s first core. I believe it was also used in the fuel in the High Temperature Gas Cooled Reactors (Peach Bottom, Fort St. Vrain) and I know that it was certainly planned for the range of General Atomics commercial plants that were cancelled in the 1970’s (Fulton Station being perhaps the most famous example.) I’ll have to check on the older HTGR’s.

    The Shippingport experiment was however an important example of how we can move forward in commercial reactors licensable right now using thorium fuels. Glad to see that someone else feels that this experiment was as important as I do.

  12. Will Davis Post author

    Nope – didn’t miss that at all. It wasn’t a commercial power reactor. Look below at a number of the varied types of reactors built for commercial power generation.

    Boiling water reactor, dual cycle: Dresden Unit 1

    Boiling water reactor, direct cycle, natural circulation: Humboldt Bay

    Boiling water reactor, direct cycle, forced circulation: Big Rock Point, all following GE BWR

    Boiling water reactor, indirect cycle: Elk River

    Sodium cooled fast breeder reactor: Enrico Fermi Atomic Power Plant (Fermi Unit 1)

    Sodium cooled power reactor: Hallam Nuclear Power Facility (Sheldon Station)

    High Temperature Gas Cooled reactor: Peach Bottom Unit 1, and later 2nd gen. Fort St. Vrain

    Organic Cooled and Moderated power reactor: Piqua Nuclear Power Facility

    Boiling water reactor, direct cycle, integral nuclear superheating: Pathfinder, and BONUS

    Pressurized water reactor: Shippingport, and many others

    Heavy water moderated pressure tube type power reactor: Carolinas-Virginia Tube Reactor

    So we can see that a large number of various coolants and cycles did reach the status of having been constructed as commercial nuclear power stations; no molten salt / fluid fuel reactor ever did here in the United States, and at this point is not prepared to in the near future either.

    There is much to be said about the early reactors following water cooling as a path, even in the light of the early high emphasis on sodium cooling because of sodium’s theoretical advantages, because the chemistry of water was so well known up until that point. Water seemed the simplistic answer and while not ideal (early designers, again, thought liquid metals were ideal) water won out. In the same sense, we might think that molten fuels are the ideal answer, but I don’t see them winning out any time soon. Rather, I see the abundant thorium being used first commercially in conventional LWR reactors.

    It isn’t as if I don’t appreciate the efforts of all those early pioneers who developed each and every technology. In fact I find some of them (such as organics) quite interesting. That doesn’t make them able to be commercialized anytime soon, though.

  13. Will Davis Post author

    “COMMERCIAL” plant, is what I said. There have been many prototypes of many kinds of nuclear reactors, but very many types were also built as commercial nuclear power plants. The molten salt reactor never was, anywhere.

    The MSR did not fly in a plane; no power reactor ever did.

  14. Tony Carden

    I have to disagree with your statement that there has never been a prototype of an MSR. There has been at the Oakridge national laboratory. It was designed by Alvin Weinberg who designed the LWR that is run by the US Navy. Weinberg’s MSR was used to fly a plane. So I do not accept your statement that MSR’s are idealized machines which have never been built. Prototypes have been built. The whole point about MSR’s is giving them adequate funding to get them to the stage where they can be proven as commercially viable or that they fail completely and are therefore abandoned as have been may other great ideas. They may well not achieve the ideals that we think they can but if they achieve 80 percent of their ideal performance they will be a long way in front of PWR’s and solid fueled reactors. Anyway the Chinese are going all out to develop MSR’s and are using the plans of the prototype built by Oakridge as a starting point. They are also looking at other designs such as pebble bed reactors so they are hedging their bets as is commercially sensible. Incidentally I live in Australia where we have no Nuclear Power and we sell our coal and uranium to the rest of the world and we have plenty of Thorium reserves as well.

  15. Chris

    Will: From your comments you’ve apparently missed the Molten Salt Reactor Experiment, a fully working LFTR prototype that ran at ORNL for 5 years, 1965-1969. What Flibe Energy and others are aiming for is to rebuild that -proven- design, enhanced by modern materials and science knowledge gained in the last 40+ years. This prototype was not “unsuccessful” at all, in fact much was learned from that early work. As has been well documented, the AEC of the time had a limited budget and a choice to make among 4 designs for civilian nuclear power, and the picked the one they were most familiar and comfortable with. Since then, the massive investment by GE and LWR plant operators has created a powerful lobby to protect those interests, and to that end, Thorium has been covered by NRC and EPA regulations to effectively prohibit domestic R&D. That sidelines private sector money, keeping MSR and LFTR on the shelf.

    The MSRE was not a failure…it was and remains politically shelved.

  16. Dr A. Cannara

    Actually, Thorium was used in a civilian reactor first at Shippingport, PA, where the 1977 refuelling was done with a new core designed to use U233 and Thorium.

    In 1982, the core was disassembled and analyses showed it contained >1% more fissile than was put in in 1977. Rickover spurred this experiment.

    And, come to AGU in SF in Dec., Booth 2617

  17. shawn disney

    Will Davis: You might want to take note that the NRC , which has unanccountably failed to develop standards for Thorium waste, (part of its Job) is not only responsible for the demise of the multi billion dollar US Rare Earth mining industry, but also a big reason for the” great expense” of Thorium MSRs. Many foreign entities, such as Japan and NATO are interested in totally funding Jim Kennedy’s proposed Thorium Co-op Utility, which the
    Will Davis: Were you aware about the German Thorium pelletized attempt to make a “Safe Fuel Rod” system of about 15 years ago? There was an accident, after assuring everyone that it was “Failsafe”. The blowback from such incidents is very damaging to the Thorium cause.
    Another thing: one big reason for the “great expense” of Thorium is the unaccountable failure of the NRC to intstitute Thorium standards. It is part of their job, but being blocked not only by Uranium fans, but the Defense Department as well. Jim Kennedy had a very promising Senate Bill S.2006 almost passed, to form a multinational sort of Thorium Co-op Utility agency, which could have enabled the restart of the former US Rare Earth mining industry, as well as other Thorium processes. It would have been funded by others, not the taxpayers.

  18. Bram Cohen

    In the case of Uranium, fuel production isn’t just mining, it’s mining and enrichment, so if you’re going to compare the costs of Thorium and Uranium you should include the costs of enriching Uranium, which shifts costs to being overwhelmingly favorable to Thorium. Enriching Uranium is expensive!

  19. Will Davis Post author

    Well, that’s all good, but you’ve ignored the — what is it now — $278.00 per hour US that the NRC charges for its work per person. Of course, the uranium fuel cycle offers comparable energy per mass of fuel and utilities buy conventional LWR plants because, generally, once they’re built the fuel cost is completely inconsequential compared to the cost of the plant. What I’m trying to say is there is no “free power,” and thorium certainly isn’t that either.

    Of course the actual cost of thorium is NOT zero, or near zero and never will be. Its abundance as stated so frequently by thorium MSR / LFTR advocates ignores its exceedingly low concentration in those deposits, and also ignores the fact that a completely new and separate fuel cycle will need to be developed — and that has REAL COSTS which I’ve so far seen stated nowhere clearly and seen discussed honestly nowhere outside of the ANS sessions I attended.

    Idealized machines which have never been built can only have a THEORETICAL cost advantage. Until and unless they’re fully designed, licensed for construction as a prototype, funded adequately, built successfully, operated, tested, and then licensed for construction in a commercialized design followed by purchase by real actual commercial utility or industrial customers there’s just no basis whatsoever to claim that they’re the sort of almost-free power that many thorium MSR / LFTR advocates claim them to be. The use of the present tense is highly deceptive in all of these discussions.

  20. Martin Kral

    If Elon Musk took your approach to new technology, there would be no Tesla or SpaceX. Innovation is the key to their success, IMO. I agree some companies should pursue solid Th fuel while others should pursue fluid Th fuel. I don’t see any utopia in that approach at all. You like solid, I like liquid and that is a good thing.

  21. Tony Carden

    It is a pity that Will has not given some time to investigating the real benefit of Thorium in a Molten Salt Reactor (MSR) and that is the cost of Thorium is inconsequential to the process. It is estimated that one ton of thorium in a MSR will provide the same energy as 3,500,000 tons of coal in a conventional coal fired powerstation.
    Doing the math if a ton of thorium is worth $80,000 and the coal is worth $50 per ton then the equivalent cost in coal is $17.5 million. Now you don’t have to have a degree in Rocket Surgery to work out that MSR’s offer a huge cost advantage. This is without factoring other costs such as the fact that MSR’s do not need huge quantities of water to act as a coolant. Imagine having cheap power in arid regions of the world or MSR’s built safely inland where they are not exposed to one in a thousand year tidal waves.

  22. Will Davis Post author

    Well, there sure is a lot of material on MSR/LFTR reactors out there these days — and lots of it is rubbish. Claims of “energy cheaper than coal” ring in my ear as do the “too cheap to meter” repeats the anti-nukes throw back at us.

    What usually happens is that the plans of visionaries, which have some sort of utopian perfect mix of fuel utilization and mechanical magic, are unobtainable and the end point of their vision (if achieved at all) is achieved through a logical process of practical engineering mixed with innovation and an ability to accept some new features into an established technology. This is clearly borne out with reactor safety vis a vis “walk away” or passive safety features in the process envisioned by Weinberg in 1985; while Weinberg had the vision to see that passive safety would be required to get the public “back behind nuclear” after Three Mile Island (even though in the US they never abandoned it in the field of public opinion) he selected unlicensed, and perhaps unlicensable advanced designs to achieve it which did not exist. (Neither was molten fuel, or used molten salt, by the way.) Instead what’s happened is that passive safety has been merged with existing technology in a way that a visionary such as Weinberg would have been incapable of seeing; his vision was for, again, a sort of utopian perfection and not a mechanical reality. See the link to this ANS Nuclear Cafe article to get more on this process:

    It’s my belief that thorium, at least initially, will enter the fuel cycle not in molten salt reactors but in the way it began to in the first place — in light water reactors. Elk River, and Indian Point Unit 1 both had thorium in their fuel in the early-mid 1960’s (initial core load for both units.) We already went down that road once, and it’s down that road thorium is going again. And, instead of planning molten fuel / molten salt reactors that have never been licensed and have no prototypes, thorium fuel pellets are being burned in a test reactor RIGHT NOW. A second run is planned for 2015. That’s real success, real achievement; and it is deliberately designed to be used in light water reactors. I believe the end point for thorium, at least for most of this century, will be in light water reactors. At least that’s the way it looks to me right now; it makes engineering sense.

  23. Will Davis Post author

    Thanks for the link – as you may know, nuclear propulsion of commercial shipping interests me greatly so I’ll have to read this in detail.. I do note however that the design referenced in this link does in fact use molten fuel, and the last attempt to seriously consider this in any way in the US for commercial operation was abandoned as unworkable in 1955 (this was the PAR or Pennsylvania Advanced Reactor, a Westinghouse aqeuous homogeneous type.) So, it’s been since that time that anyone has seriously (by that I mean “spent a lot of money on”) considered commercial licensing of a fluid / molten / suspended fuel reactor in the United States as a power reactor steam supply system. Having said this I will say I noticed at first brush the authors’ disdain for the thorium breeder concept, and so I’m pretty sure that they do have one foot in some sort of reality.

    I look forward to reading that treatise in detail, perhaps Wednesday when I have a large chunk of time, and I thank you again for that link and the clarification.

  24. Chris

    Will, that link of Robert’s should be rather than which points to Flibe. Thor Energy whom you quote in response is developing solid Thorium-MOX fuels for LWRs, and is unrelated to Martingale Inc.’s ThorCon molten salt reactor.

    The ThorCon executive summary goes into extensive detail about their design, which requires no new technologies and could be prototyped in four years. Ultimately it would scale much more rapidly than is possible with conventional nuclear. LWRs will play a part throughout the century, but there is no way that they will scale to meet global energy demands in time; the construction times and expense are simply too great.

  25. Harry Bryant

    “I am not a scientist” ;o) not a nuclear scientist anyhow, but what I’ve read in the lay literature leads me to think that MSR/LFTR is the way to best utilize thorium. Seems to me that any LWR is old technology.

  26. publius

    Always remember that Shippingport used a thorium-uranium fuel, with enrichments (that is, the proportion of fissile to fertile material) no higher than 5%, from 1977 to 1982, with a net gain in total fissile content. I believe Naval Reactors did most of the development work under the “Advanced Water Breeder Applications” programme, including qualifying “pre-breeder” 235-U/Th fuels.

  27. Ed Pheil

    I was there too and it was focused on Th in LWR’s with only Jesse Gehin at ORNL briefly discussing LF-MSR’s. I think we work on new fuels for existing reactors while working to get to the next better, safer, lower cost next generation. IF you don’t work on the LF-MSR’s, you would never get there. Some need to work on it.

    Also, it didn’t take 50-60 years to build Indian point and Shippingport so should not take that long to develop TMOX fuel with today’s technology and caoability.

  28. Will Davis Post author

    It’s my belief that the firms interested in LWR thorium fuel are absolutely looking at higher enrichments, yes. I heard values up to 20 percent during some sessions as I recall. I cannot give a sense of the average between widely disparate projects, however. I will certainly look for your quoted source, and I thank you for it!

  29. Will Davis Post author

    Thanks for reading and commenting, Robert. Of course, I see that your comments are pointed at molten salt, and while there might be a place for those down the road, the guys at Thor Energy have it exactly right — they say that “the LWR is the power reactor of choice for at least the rest of the century,” and that thorium introduction must be “evolutionary, not revolutionary.” There is no practical purpose in racing all-out for the pot of gold at the end of the rainbow when the last chase for it ended up in no commercial power reactors having been attempted. Instead, it makes sense to get the abundant material into the established, licensed technology first – and that’s what this article is all about. Perhaps by the date that any utility might be interested in a fluid fuel reactor or a molten salt cooled discrete fuel component reactor, the thorium supply (in reactor grade) might be established and stable this way. It’s a realistic approach from both an engineering and licensing standpoint, don’t you think?

    I will definitely go have a look at your link!

  30. Robert Hargraves

    Will, Thanks for detailing some of the sources of thorium. I didn’t present them in my book, THORIUM: energy cheaper than coal. Thorium is not just a nuisance in mining US rare earths. Its half-life is about that of the age of the universe, but the government NRC thinks it is a “source” material subject to restrictions and the EPA thinks its a hazardous material though it decays very slowly. These restrictions on US rare earth mines are the reason China has a seeming monopoly on rare earths. Jim Kennedy is trying to get this fixed with legislation.

    The cheapest sources of thorium must be the beach sands of monazite in India, Turkey, and Brazil.

    Thorium is particularly useful in molten salt reactors, because processing the U-233 bred from Th-232 is so much simpler than with solid fuels. MSR designs are progressing faster than you know. For evidence read the ThorCon Executive Summary, now open source, at

  31. Joseph Sapyta, PhD

    Readers of this article and the author should read the July 2004 Nuclear Technology VOL 147, NO 1) that is devoted to using Thorium in modern day light water Reactors. It is not promising for use in low enriched LWR’s. (Core Designs and Economic Analyses of Homogeneus Thoria-Urania Fuel In Light Water Reactors) M Saglam et al.

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