IFR FaD 6 – fast reactors are easy to control

There are many topics in the IFR FaD series that I want to develop in sequence — and in some detail. But for the moment, here’s a little diversion. People often complain that sodium-cooled fast reactors are about as easy to control as wild stallions — at least compared to the docile mares that are water-moderated thermal reactors. The experience on the EBR-II (which I’ll describe further in future posts) certainly belies this assertion, but for now, I want to go to another source.

Here are comments from Joël Sarge Guidez, written in 2002, who Chairman of International Group Of Research Reactors (IGORR), Director of Phénix fast breeder reactor (a 233 MWe power plant which operated in France for more than 30 years, with an availability factor of 78 % in 2004, 85% in 2005 and 78% in 2006), and President of the club of French Research Reactors:

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A reactor that’s easy to live with

  Pressurised water reactor specialists are always surprised how easy it is to run a fast reactor: no pressure, no neutron poisons like boron, no xenon effect, no compensatory movements of the rods, etc. Simply, when one raises the rods, there is divergence and the power increases. Regulating the level of the rods stabilises the reactor at the desired power. The very strong thermal inertia of the whole unit allows plenty of time for the corresponding temperature changes. If one does nothing, the power will gradually decrease as the fuel ages, and from time to time one will have to raise the rods again to maintain constant power. It all reminds one of a good honest cart-horse rather than a highly-strung race horse.

 Similarly, the supposed drawbacks of sodium often turn out in practice to be advantages. For example, the sodium leaks (about thirty so far since the plant first started up) create electrical contacts and produce smoke, which means they can be detected very quickly. Again, the fact that sodium is solid at ambient temperature simplifies many operations on the circuits. More generally, because of the chemical properties of sodium, the plant is designed to keep it rigorously confined, including during handling. During operation, all this provides a much greater “dosimetric convenience” than conventional reactors. In particular, a very large part of the plant is completely accessible to staff whatever power the reactor is at, and the dose levels are very low.

Because of the very high neutron flux (more than ten times as high as with water reactors), there is great demand for experiments. These experiments are performed using either rigs inside carrier sub-assemblies or using special experimental sub-assemblies with particular characteristics. All experiments are run and monitored in the core like the other subassemblies.

Since the origin Phénix irradiated around 1000 sub-assemblies, on which 200 were experimental sub-assemblies. It is true that the Phénix is not as flexible as an experimental water reactor, in which targets can easily be handled and moved. But, with a minimum of preparation – which is necessary anyway for reasons of safety and quality – numerous parameters such as flux, spectrum and duration can be adjusted to the needs of each experiment.

Furthermore, the reactor was designed by modest people who thought in advance of everything that would be needed for intervention on the plant: modular steam generators, washing pits, component handling casks etc. All of which has been very useful and has made possible numerous operations and modifications in every domain. All this has meant that a prototype reactor built in the early 1970s is still operational in 2004, and will continue so for several years yet.

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Some further useful information can be had from Guidez’s presentation at the 2008 International Group on Research Reactors conference. Download and read over this 19-page PDF, which is the easy-to-read slides of his presentation, called “THE RENAISSANCE OF SODIUM FAST REACTORS STATUS AND CONTRIBUTION OF PHENIX”.

Next up on this topic, I’ll write-up my recent experiences when visiting the EBR-II in Idaho Falls in August 2010.

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71 Responses

  1. Opposition to liquid sodium might be difficult for some anti-nukes who favour storage methods like the Zebra battery with its 250C sodium cathodes. Still the rationale ‘so we know where the leaks are’ is a bit like the way councils put red dye in weed spray. A sodium fire would be short lived albeit intense compared to say a big tank farm fire.

    How does sodium compare to molten fluoride for corrosion in ferrous alloy pipes?

  2. Sodium is non-corrosive to steel and the fission products are held in the metal fuel/cladding — after 30 years, when the sodium tank was drained in EBR-II, the welding marks were still clearly visible.

    As someone pointed out elsewhere (maybe it was you John), there is a hot sodium battery powered Bus driving around Adelaide using one of those Zebra batteries! http://envirofuel.com.au/2007/12/26/adelaides-solar-electric-bus/

  3. In the peak oil field one commonly sees the contrast between the optimistic predictions of oil availability from oil companies and governmental energy agencies and the predictions from scientists and retired petroleum engineers who use the past large-scale behaviour of the “system” (the world oil extraction enterprise) to model its future performance.

    A similar conflict may exist here at BNC. Here we find many enthusiasts for expansion of nuclear energy using breeder systems but readers may not be aware that critics of such reactors exist who are not simply biased anti-nuclear campaigners. A nuclear physicist working at CERN, Dr Michael Dittmar has analysed the real past performance of breeder technologies and found them to be significantly below their theoretical capabilities. You can read his fascinating critique (titled, “The Future of Nuclear Energy: Facts and Fiction – Part IV: Energy from Breeder Reactors and from Fusion?”) here:

    http://energyandourfuture.org/%7Eeurope/node/5929#more

    Here is a short quote from the conclusion of this very long and data-rich article:

    “In this fourth and final part of our analysis about the Future of Nuclear Energy, we have presented status and prospects for nuclear fuel breeder fission reactors and the true situation as it relates to nuclear fusion.

    Despite the often repeated claims that the technology for fast reactors is well understood, one finds that no evidence exists to back up such claims. In fact, their huge construction costs, their poor safety records, and their inefficient performance give little reason to believe that they will ever become commercially significant.

    Indeed, no evidence has been presented so far that the original goal of nuclear fuel breeding has been achieved. The designs and running plans for the two FBR’s, currently under construction in India and in Russia, do not indicate that successful breeding can even in principle be achieved.”

    Dittmar is slightly more enthusiastic about thorium-based breeder systems but sees little prospect of their development in time to counter the large anticipated drop-off in energy from fossil fuels.

    It is clear from Dittmar’s article that he is concerned, in general, about nuclear proliferation but it is also evident that he has taken a careful and quite objective view of past breeder reactor performance and the stated performance of the reactors currently under construction. The lesson for us all is that real-world performance never matches theoretical possibilities and our optimism for Gen III and Gen IV reactors (for many driven by desperation over the climate change and/or peak fossil fuel situation) should be tempered by this knowledge.

    On a related issue, reading the comments on sodium leaks and how convenient these are to control led me to muse about how one would control a really large leak (e.g. due to catastrophic failure of a conduit under pressure) that one would expect to occur eventually if there was a worldwide rollout of hundreds of sodium-cooled reactors. Of course, the resultant fire could not be smothered with water and spraying oil onto it would be ineffective since it would simply combust at the high temperatures. The only way would be to flood the area with e.g. nitrogen or carbon dioxide gas but how does one do this on a large scale? Even if the leak was at the bottom of a hole that cold be capped and gas-filled one would have to be immensely careful with the asphyxiation danger to personnel. The people who propose to build these things must have thought of ways to control the fire from a large scale leak so it would be interesting to hear what the method is from someone who knows.

  4. ” how one would control a really large leak (e.g. due to catastrophic failure of a conduit under pressure)”

    What conduit is under pressure? These fast reactors operate at atmospheric pressure.

    Lardelli, you come across as a pretty desperate doomer who is clutching at straws. I can see why you sympathize with Dittmar. He tells you exactly what you want to hear. The catch is, he’s spouting a load of old cobblers and you’re hooked.

    I think this comment from Engineer-Poet on Kirk Sorenson’s blog gets to the point:

    It was the issue of SWU which proved that Michael Dittmar’s series on The Oil Drum last year was a pack of lies (I use the term deliberately). Dittmar never mentions separation, as if it was toxic. When it was brought up to him repeatedly in the comments, he danced around the issue without ever addressing it. The editors repeatedly censored the commenters who pointed out where Dittmar was deliberately avoiding the facts which contradicted his claims. Dittmar also avoided any mention of thorium.

    In other words, there is a conspiracy in prominent circles to avoid the facts because they contradict the narrative the doomers have constructed for public consumption (“there is no hope, power down”). The doomers may be correct that nuclear power may be taken down by a general collapse following a fossil-fuel crisis and leave us with a very dangerous legacy, but the public would not go along with power-down and would instead demand that nuclear power be expanded rapidly to avoid the crisis at the outset.

    There is a lot more about Dittmar’s tactics and The Oil Drum ‘orthodoxy’ here, which is required reading:
    http://ergosphere.blogspot.com/2010/05/enforcement-of-orthodoxy-at-oil-drum_09.html

    No wonder Barry hasn’t bothered to engage with him.

    And no, I am NOT Engineer Poet – I just respect his writings. Both he and I are also deeply concerned about peak oil. It is inevitable. But it doesn’t help society prepare for this by denying the clear role that nuclear energy has, because it suits your weirdly malformed world views on society.

  5. After spending a summer at Argonne National Lab, I have to say that Dittmar’s assessment is not at all in line with the prevailing thought in the US fast reactor community.

    And with good reason, I think. If Dittmar’s pessimism were applied equally to all new human endeavors, we would still be living in caves.

    Take this quote for example:
    “In fact, their huge construction costs, their poor safety records, and their inefficient performance give little reason to believe that they will ever become commercially significant.”

    This could just as easily have been said of LWRs 20 years ago. Nearly every fast reactor constructed to date was experimental or prototypic. Aside from the recently completed CEFR and the soon-to-be-restarted MONJU, all of the fast reactor operating experience comes from plants built over 25 years ago.

    In particular Dittmar’s claim that “breeding has never been achieved”* is completely unjustified. His*only* basis for this claim is that no one has done the complex destructive analysis necessary to prove a net generation of fissile atoms. Dittmar even explicitly acknowledges one reason for this: it would be very expensive to do this.

    In any case, this approach is not actually necessary to confirm breeding in some systems. As additional fissile material is generated, it increases the system reactivity, while fission products generated impose a small reactivity penalty. Breeding can be observed by tracking the changes in system reactivity, provided that the additional reactivity generated by breeding more than offsets that imposed by fission products. This would be most evident in a system which utilized internal blanket assemblies.

    *Dittmar must mean something like “a breeding ratio greater than 1 has never been achieved.” Breeding occurs in every reactor system with fertile material, including LWRs, although conventional reactors do not generate more fissile material than is consumed. I have assumed as much above.

  6. On the issue of breeding, this presentation suggests that breeding was confirmed by the former USSR’s first fast reactor BR-1 commenced in 1955. Breeding ratio 2.5 measured.

    http://www.physor2008.ch/documents/Technical_II/PHYSOR08-TechnicalII-04.pdf

    I’ve also read that the Russian BN-800 is specified for a breeding ratio up to 1.3. I find it hard to believe that the Russians are telling porkies of this magnitude when they have established a joint project with China to build two of these things.

  7. I hope Lardelli doesn’t go around using his prestige as a lecturer in genetics to alarm young uni students with his doomer nonsense. A young person with a predisposition toward depression dealing with the stresses of a novel and high pressure environment could be seriously impacted by that stuff.

  8. Michael Lardelli wrote:
    Dittmar is slightly more enthusiastic about thorium-based breeder systems but sees little prospect of their development in time to counter the large anticipated drop-off in energy from fossil fuels.

    We don’t need to have only breeder reactors in place when fossil fuels fall off. There is a good deal of uranium 235 around to power conventional reactors (that do breed somewhat, and produce a significant amount of power from plutonium towards the end of life for the fuel). That U235 gives us time to develop uranium and thorium breeder reactors. So let’s get busy! But there is nothing wrong with a step-by-step approach.

    Dr. Dittmar is making the perfect the enemy of the good. But both the good (light water reactors) and the “perfect” (breeders) better than the present situation (fossil fuels).

  9. Error piled on error is the gas interests’ tendency. When they argue that breeder reactors are impracticable this is, by implication, an argument that they are necessary for nuclear power’s long-term future. In fact they are practicable — and optional.

    The comments on Dittmar’s recent Guardian article, much more worthwhile than the article itself, show this. They include a link to a summary of the most recent “Red Book” report.

    Its uranium reserve estimate, compared to that of its 2007 edition, has increased 1144 tonnes per day. The same rate of change of the RB estimate from 2005 to 2007 was … can’t find my note on this, but I seem to recall it was minutely less, ~1100 t/d. That’s comfortably more than the petroleum burn rate, which is ~800 uranium-tonne-equivalents per day. (Or eight UTE/d, in an all-breeders world. OK, eight uranium or thorium tonne-equivalents.)

    Part of my Guardian comment:

    100000 years turns out not to be very long compared to the sustainability of existing non-fusion, non-breeder reactors. Hectopetawatts are a useful measure. Sunlight absorption at the Earth’s surface amounts to 1.2 HPW, and so nuclear regulators are never going to allow more nuclear thermal power to be produced here than about a fiftieth of that, ~0.024 HPW.

    Now, because of chemical differentiation over the ages, half the uranium in the whole planet now appears to be in the continental crust. It is as if half the sugar in an apple were in the skin. And not even all of the skin, rather, half is in slightly thickened blotches covering only 29 percent. It’s within present-day drill range. If it could all be finessed to the surface and into reactors like today’s, it would enable them to give 0.024 HPW for 270,000 years. Moreover, there is no doubt that its energy far exceeds the energy necessary for the finessing. At a uranium concentration of 0.00025 percent by weight, a typical continent has the same energy density, 1.5 MJ/kg, as tar sands that are 3.5 percent tar, and in recent years such sands have been providing energy that was about 80 percent net.

    Disruptive extraction methods no doubt won’t be allowed, but the most concentrated 1 percent, extractable by processing much less than 1 percent of the crust, is plenty for the next 100 generations, and this seems like plenty of time for developing non-disruptive extraction methods, or breeders, or fusion, or mass downlift, or gas-lobby-displeasing varieties of renewable energy. Nuclear advocates who get tricked into defending breeders as if it were possible for existing nuclear power to run scarce this millennium, please take note.

    (How fire can be domesticated)

  10. Not able or knowledgeable enough on the fission versus breeder reactor, I shall nevertheless throw my hat in the ring. If I were chairman of the board of REALLY BIG ELECTRICITY CORP , somewhere on the planet Earth, and today’s boardmeeting HAD to decide which type of reactor are we buying/financing /operating for the next 50 years? Then the answer would have to be PWBW .
    It is a no brainer in the real world. It works , it is proven, it is here now, and you buy it off the shelf so to speak.

  11. Oops, PBWR

  12. Don’t you mean Pebble bed Modular Reactor (PBMR)?

  13. Sodium — All atmospheric containers around sodium pipes and heat exchanges to be filled with argon (which is easily obtained in quantity).

    Sodium fires a non-issue for (intact) NPPs.

  14. While I’m not too worried about sodium leaks as such surely

    “For example, the sodium leaks (about thirty so far since the plant first started up)”

    calls the quality of the engineering of the whole plant severely into question? Whilst, no doubt, it is theoretically possible to run these plant at a standard that would reassure the general public, I am afraid that the actual real engineering history of reactors is less than optimum in this regard.

    Right from the start in the 50′s the nuclear industry were saying that they got things right and things were safe when they manifestly weren’t. Excessive public relations optimism.

    The problem you have to deal with is that the nuclear industry has been saying that there is no wolf for so long that nobody believes them any more.

  15. The problem you have to deal with is that the nuclear industry has been saying that there is no wolf for so long that nobody believes them any more.

    Oh, I rather think that it’s the antinukers who are in trouble over crying wolf and jumping at shadows of their own manufacture, and it is this which the world is now seeing through.

  16. Nick Palmer, on 8 September 2010 at 9.10 — In the USA, every NPP reports incidents and accidents to the NRC. While incident rate is up as the NPPs age, the accident rate is way down as the operators have learned what to do.

  17. From Midhael Dittmar’s essay, linked to by Minchael Lardelli:

    “Indeed, no evidence has been presented so far that the original goal of nuclear fuel breeding has been achieved. The designs and running plans for the two FBR’s, currently under construction in India and in Russia, do not indicate that successful breeding can even in principle be achieved.”

    This is truly a bizzare claim. How is it possible that the engineers involved in these projects would overlook such an issue if there were any validity to it? But more significantly, if it is true, then where did all the plutonium come from which the anti-proliferation crew are so worried about? I mean seriously… it is estimated that a significant portion of the fission reactions in the fuel of a standard LWR as the fuel gets into the second half of its tenure comes from the plutonium which has been bred in it. Please note that this is for a LWR, not an FBR.

  18. I keep reading about the advantages of thorium in electricity generation. Does anyone know if thorium is a feasible alternative to other forms of energy creation – ie advantages/disadvantages, etc?

  19. I keep reading about the advantages of thorium in electricity generation. Does anyone know if thorium is a feasible alternative to other forms of energy creation – ie advantages/disadvantages, etc?

    Thorium breeder reactors possess certain features which will likely enable them to be highly effective in producing power cheaply and plentifully once they move into the commercial stage. At the moment, thorium advocates are going off work done in the development of prototypes from 30-40 years ago. The long term outlook for them appears to be very good, but some work remains before that potential can be realised. For more information, check out the Energy from Thorium website:

    http://energyfromthorium.com/

  20. Rapid Rabit said (in relation to ‘peak oil’):

    In other words, there is a conspiracy in prominent circles to avoid the facts because they contradict the narrative the doomers have constructed for public consumption (“there is no hope, power down”).

    But surely no regular BNC contributors would fall for for the doomers’ scare campaign, would they?

  21. Finrod raised concerns about young people and depression. It’s real mate. Tas McKee was a young bright bloke studying Engineering at UNSW. He was on the ROEOZ doomer list that Michael has been influenced by. Tas committed suicide over this stuff. I’ve met with Tas’s father Geoff to compare notes over what happened. It’s the INEVITABILITY of collapse that ROEOZ present that move it from a healthy respect for the challenges ahead into what I now think of as having much in common with cults.

    http://www.energybulletin.net/node/47559

  22. Dittmar bases his assertions about past and planned reactor performance on publicly available information. It is easy to show that Dittmar’s arguments are false – all you have to do is show how the information he cites is incorrect or that he has cited incompete information in a misleading way. Note however that it is not enough merely to state that he is wrong. You need to show it by presenting your own information or invalidating his. Evoking doomer conspiracy theories is unnecessary. The nice thing about scientific arguments is that they are based on data rather than on whose voice is loudest or most insulting.

  23. It is easy to show that Dittmar’s arguments are false – all you have to do is show how the information he cites is incorrect or that he has cited incompete information in a misleading way.

    It’s already been done. Just read through the criticism he recieved on the comment thread to the Oil Drum article.

  24. Sodium fires a non-issue for (intact) NPPs. – David B. Benson

    in terms of nuclear safety, rare is not never. The more dangerous stuff you put into a reactor core, the greater the safety risk, and sodium is certainly more dangerous than water. It costs more to maintain nuclear safety when you do something risky. Cost more means you are going to pay some way. There are safer coolants for fast reactors than sodium, and incidentally coolant that can produce power with considerably greater thermal efficiency.

  25. Charles Barton,

    What is the situation with Sodiium Sulphur batteries? Are the dangerous and if not, why not?

    They operate at about >300 C from memory and they are being deployed in cites (New York, Tokyo etc). they are the largest batteries (>MW) available and are being used for for peak shaving and firming wind power. It seems there is no major risk or they would not be being deployed in cities.
    http://www.electricitystorage.org/ESA/technologies/sodium_sulfur_batteries/

  26. Peter, never is a dangerous word. Are you going to get a sodium fire every now and then, with a sodium-sulpher battery?

    You bet ya.

    How dangerous is that?

    Well prudent designers are going to take the fire danger into account, and design to avoid the worst consequences. You don’t get safety unless you take your safety problems seriously, and the use of metallic sodium in any industrial system always poses safety risks. Those problems can be solved, but safety solutions have costs.

  27. OK Finrod – I did what you told me and it took literally hours to get through the 380 odd comments! I’m not sure I’m much the wiser after it. Engineer Poet discredited himself by reverting to insults (he might have had valid points but what is one to think when it is mixed in with such) while Loiz made a much more objective effort. It got a little bizarre half way through when they discussed detonating nuclear devices in enormous evacuated caverns deep underground as huge heat exchangers! However, I thought the best comment came from Roger (Nov 10, 11.48 PM) who said…

    “The biggest technical flaw that I see is that you confuse the concept of the “fast breeder reactor”, as it was originally formulated, with the current concept of the “fast burner reactor”. (In this case, I’m using “confuse” in the active sense of “creating confusion”, rather than the more common sense of “to be confused about”. IOW, I’m accusing you of creating rhetorical confusion — a charge against which you will probably want to defend yourself. En garde’!)

    The original concept of the breeder reactor is that it would produce excess plutonium that could then be processed and used to fuel older conventional reactors. That concept was abandoned years ago, for a variety of reasons, yet you use the slightly negative breeding gains of new designs to try to discredit the whole class of fast reactors. Sorry, but a near-unity to slightly negative breeding gain “is a feature, not a bug”. That’s how they’re supposed to work.

    Think about it. The initial load of enriched uranium is like the kindling used to start a fire. Once the fire is started, you just keep feeding it wood — the “wood” being depleted uranium and wastes from once-through reactors. So what if your fire is not producing kindling for other fires? It doesn’t need to, because there are adequate kindling supplies available from conventional sources.”

    … and Dittmar failed to answer this.

    Other interesting comments were from Francesco Spano (November 15, 2009 – 7:52pm) regarding ELSY which suggested there were major obstacles to be overcome with development of that system. (Too long to copy in here but worth the effort to find and read.)

    I suppose the comment that came closest to my mentality was from “Styno”…

    “I won’t be able to critically analyze the fundamental physics or engineering difficulties, like most people do. And I have a degree in applied physics so I should be able to get further in understanding then the average layman. What I can do is try to filter the real arguments between from the plain bullshit, insults, propaganda and unfounded opinions.

    I’ve come to the conclusion some time ago that I’m not going to be on futuristic super high tech solutions. It’s not that I don’t think that commercially successful, safe and reliant liquid thorium reactors aren’t near future or not. One of the reasons is that there are also social implications with super giant energy monopolies and the way they manipulate politics and influence the price to pay for electricity for their profit.

    So I’m going to conserve, be more self reliant without having a less comfortable life. In fact, for instance, using better insulation improves comfort levels, cycling to work improves health, eating home grown food get’s me out of the house more and it tastes better. My self made manual transfer switch allows me to ride out a blackout using my solarpanels, and the food in the fridge stays frozen. I can even make a cup of coffee in the evenings. The savings in avoided cost in buying ever more expensive electricity and natural gas is easily earned back.

    I understand solarpanels, electronics, wind, storage and can build/use/influence/repair them. I see the long term final cost for me and notice it’s cheaper then unproven future monopolized and centralized tech. With this in mind and since there are many concerns about the nuclear chain, why would I be enthusiastic about it?”

    Also Finrod, just to reply to an accusation you made on the peak oil thread – you accused me of trying to slip around the issue of EROEI for nuclear in my essays on energy. The point to be made on this from the “Oil-Energy Connection” essay is that it would be possible to calculate the EROEI of a Gen IV nuclear reactor only once it had been built and operated. The essay was expressing the idea that the cost of building and operating the nuclear plant as a proportion of the entire economy (and considering the fraction of the total energy in the economy supplied by the plant) could be used to calculate the EROEI. (The essay made this argument for oil but it would apply to nuclear just as well.)

    I will still place myself in the skeptical camp regarding whether nuclear will be a solution. As you know, I have doubts as to whether a world in energy decline – as we now appear to be – will be able to remain sufficiently complex and “just-in-time” to provide the technology to do it (once any bugs are ironed out). Certainly I think that concentrating on one solution is a mistake. As to whether price signals will save us in future – just look at all the stalled apartment developments (planning permission granted but waiting for finance) in Adelaide in the midst of a house price boom! Economics is obviously more complex than that. Price signals may work for non-energy resources in an environment of energy abundance but when the resource being exploited is the source of the energy itself you will see the “receding horizon” effect – i.e. as the price of energy rises the price required for economic exploitation of the energy source rises too. This is the reason why oil shale will never be economically viable and the effects will apply to the nuclear industry too. For example, I read somewhere at this site that a Gen IV reactor would cost $8 billion – but at current rates this is equivalent to 360 km of tram line (if 4 km of tram line costs $100 million). Seems a little cheap to me!

  28. Michael Lardelli, thanks for those comments, but I will be talking explicitly about breeding gains and fissile requirements of fast reactors in future entries in the IFR FaD series. I’ll hold my comments on this complex topic for now, because it will just muddy the waters at this stage. But suffice to say, breeding of well above 1 is possible with metal fuels, with the actual ratio depending on a range of factors. The upper limits are around 1.65 to 1.8. It’s based on fundamental physics, and is no more mysterious than the fusion reaction that goes on in the sun — we haven’t gone and measured it directly, but we know it is a reality.

  29. Charles Barton, on 8 September 2010 at 14.07 — What do you suggest to replace sodium?

  30. David B. Benson, i don’t recommend that sodium be replaced. Some safety issues cannot be avoided. There are both risks and benefits to sodium use. By now fast reactors technology has developed very sophisticated safety work arounds for LMFBRs. Although they should not be regarded risk free, iFRs are approach although probably do not equal Molten Salt Reactors in safety. But you pay a price for IFR safety. MSRs are probably going to be considerably cheaper to build and a ton of fissionable material will start a 1 GW of MSR of a 100 MW IFR.

    There are, of course alternatives to sodium cooled fast reactors,. For example my father researched a chloride salt cooled fast breeder reactor that had many advantages over the LMFBR including a much higher operating temperature and a non-flamiable coolant. Its biggest flaw was that it had been invented in Tennessee, not Chicago. A Liquid Chloride Fast Reactor will probable save money on safety, but will need the same size start up charge as a IFR.

  31. I’m still skeptical of the LFTR. Everything Charles, Kirk, and so on has been extremely convincing… but it seems too fantastic. I still don’t understand why practically everyone is predominantly researching the LMFR instead of the MSR. And it’s not just the US, what about, for example, Japan, China, and India?

    Additionally I am skeptical of the LMFBR too. The few LMFBR reactors that have been constructed have been significantly more expensive than LWR types, and less reliable. It is understandable in some ways, because these were FOAK reactors. Superphenix for example, was approximately twice the size of an equivalent (MWe) LWR. A later design of Superphenix, the European Fast Reactor (EFR) was estimated to cost approximately the same as a LWR. But it seems like it will be an up-hill battle to reduce these costs.

  32. Also, what about the GFR? Do these have the same issues with size as the PBMR?

    http://nextbigfuture.com/2010/09/general-atomics-to-develop-energy.html

  33. I’m still skeptical of the LFTR. Everything Charles, Kirk, and so on has been extremely convincing… but it seems too fantastic. I still don’t understand why practically everyone is predominantly researching the LMFR instead of the MSR. And it’s not just the US, what about, for example, Japan, China, and India?

    I should think one reason is that there is a substantial body of engineering knowledge related to LMFRs gained through operation of real reactors. MSRs not so much.

  34. Ian George,
    Finrod sent an excellent link on Thorium reactors. I recommend the following link as being “fun” at least from a physicist’s perspective. You can find the same video on Finrod’s link but it may take a little digging:

    Dittmar is such a pessimist that he sees nothing positive in IFRs. For that he has been thoroughly debunked here. As an LFTR enthusiast I did get some encouragement from the fact that he could not come up with any arguments against Thorium “breeders”.

  35. “I’m still skeptical of the LFTR. Everything Charles, Kirk, and so on has been extremely convincing… but it seems too fantastic. ” – Scott

    Scott, have you ever looked at the Energy from Thorium document archive. LFTR advocates do a whole lot better job of offering the basic research documents to the public than IFR backers have. In addition I have a personal aspect to the story since my father engaged in MSR research over a 20 years period a time, and made a number of pioneering contributions, to the technology. (My father also made a major contribution to Light Water Reactor technology.)

    Given the quality of the ORNL’s documented MSR research, the claims that Kirk and I make are credible. The reality we point to just strikes people as being too good to be true.

  36. Since we can provide all the worlds energy needs for the next millenium on existing nuke waste, the breeding argument is a canard. A nice feature but maybe not worth the cost.

    There are no doubt lots of uranium deposits in the asteroids. I’m sure we’ll be finding them in the next 50 years. By then our cars will likely be powered by Mr Fusion units.

    The ultra simple DMSR is the obvious way to go, well within the capabilities of numerous nuclear suppliers to build and I wouldn’t be surprised if a few are under construction in some secret corporate “skunkworks” operation. You might ask Sorensen what he knows about that.

    The Indian first of a kind 500MW commercial fast breeder due for service next year was built at a cost of $1.5B/Gw in six years based I believe on the french design.

    Lotsa hyper efficient fast reactors that don’t breed are are near production (hyperion,4s) and if imperfect the Soviets were able to run their deadly Alfa on a fast breeder for years.

    And then there are the accelerator driven units and of course Bill Gates.

    The cost argument is bullshit.

  37. Seth we can start them with nuclear waste, but we can’t keep them going without breeding, and breeding with LFTRs is not expensive. it is possible to breed with a DMSR. It is quite possible that the first 21st century MSRs will be be uranium fuel cycle converters, however.

  38. Charles Barton, on 10 September 2010 at 4.44 — DMSR?

  39. Denatured Molten Salt Reactor, for those who enjoy unnatural nuclear lust. A DMSR is a thorium converter/breeder with U-238 mixed in, to prevent the recovery of weapons grade U-233 by would be proliferators.

  40. With the many varieties of Gen IV being discussed the most important criteria, cost, is invariably missed or down played. We need cost estimates by qualified estimators. Cost estimates by physicists and other advocates for a technology have no credibility. They are probably worse than the estimates from the RE advocates.

  41. […] Brook at Brave New Climate steps through the reasons fast reactors are easy to control citing the IFR as an example. He says pressurized water reactor specialists are always surprised […]

  42. Charles Barton,
    We need to avoid making the good (IFRs) the enemy of the better (LFTRs). The IFR folks are our friends and it may turn out that their technology will be more successful in the marketplace.

    We need to see IFRs and LFTRs competing in the real world in the business of delivering affordable electric power absent of all government carrots and sticks. No more subsidies and no more prohibitions that make no sense.

  43. This might be a stupid question, or addressed previously, but rather than trying to built larger FB prototypes couldn’t we just build massively roll out the small ones that have been previously developed? For instance, couldn’t we just build ~4 phenix type reactors in place of a single 1 GW plant?

  44. gallopingcamel, Similar advice needs to be offered to iFR advocates, who sometimes seem to be sending LFTR advocates the message, “we don’t need you..” i have advocated working together toward common goals, but my suggestions have received a cold shoulder.

  45. Charles,

    Perhaps you could clear a few misunderstandings I may have that relate to IFRs and LFTRs.

    The IFR, as I currently understand, is a single design (S-Prism) in the class of fast reactors that are sodium cooled. The BN600 is another sodium cooled fast reactor design already in production. The latter is fuelled with metal oxides but the former with metal, allowing pyroprocessing – which I assume is the reason for preferring it.

    However, I understand that the term LFTR relates to a bewildering array of different designs, having in common molten salt cooling and fuelling and the use of thorium – either mixed or separated from uranium and with continuous reprocessing onsite. If I am correct, do you not think that the multiplicity of designs reduces or enhances the chance of any single one ever getting built? I also understand that most of the the initial research was conducted at Oak Ridge in the States and was subsequently carried on in Japan with joint funding from the States, Russia and Japan. This project appears to have run out of funding. Given the promise of the technology, as eloquently set out by its supporters, how do you explain that this funding has been allowed to lapse?

  46. Douglas, you are correct that there is a whole class of Molten Salt Reactors, which can include both chloride and fluoride salt cooled reactors, single fluid and two fluid reactors. Fluoride reactors can be moderated by graphite, heavy water, by fluoride salts themselves, or even be relatively unmoderated fast neutron reactors. Chloride reactors are fast reactors.

    There has been limited research on Chloride Salt fast reactors, despite some notable advantages over metallic sodium. They share on major disadvantage with IFR, the size of the load of fissionable materials required to maintain criticality.

    I don’t see the multiplicity of potential MSR designs as a disadvantage. It gives engineers choices about which features to emphasize, The chemistry problems are significantly easier with two fluid MSRs for example. Using a core salt moderated design, eliminates some problems with graphite moderated MSRs, but requires a larger load of fissionable material to maintain criticality.

    The Two Fluid Le Blanc tube core is the simplest reactor core that will ever be designed.

    The choice between the MSBR in the late 1960′s and early 1970′s was not made rationally. AEC Chairman, Glenn T Seaborg won a Nobel Prize for the discovery of plutonium and had what amounted to a proprietary interest in the advancement of plutonium breeding technology. Other inside the beltway figures preferred
    the fast reactor for reasons that had to do with technical features. Seaborg, and several politicians and politically minded administrators in the AEC, appear to have convinced the Nixon Administration that the LMFBR was the way to go, and that research on other potential breeder options should be shut down so that funding could go to LMFBR research. This decision was a big mistake and ultimately lead to the wasting of billions of dollars with nothing to show for it.

    it is clear that the MSBR was technically superior to the LMFBR candidate, the Clinch River Breeder Reactor, which was eventually to prove an expensive failure. Argonne National Laboratory then redesigned the LMFBR to match MSBR features. That was the IFR. The IFR has several disadvantages when compared with recent EfT design concepts.

    During the Nixon administration a report was prepared by the AEC to justify the decision to kill the MSBR. Reasons included the argument that the the LWR and the LMFBR were mature technologies, while the MSBR was not. Three Mile Island was to prove the report wrong on the LWR, and the LMFBR was from from mature. in fact far more money was spent on the failed Clinch River Breeder Reactor that would have been required to develop MSBR. The report also argued rather absurdly that the MSBR should not be developed because it needed to be developed. The US Department of Energy has never taken another independent look at Molten Salt Reactor technology, and, as of last year, continues to reference the very flawed WASH-1222 for its MSR evaluation.

    The MSR was considered dead until 4 years ago when Kirk Sorensen, David Le Blanc, David Walters, myself, and a few other people who understood the potential of MSRs and thorium started to work to educate people about it. I knew about the MSR because my father was a pioneer development, and did research on it at ORNL for 20 years.

    The EFT crowd, is likely to produce a 2 fluid thermal fluoride salts thorium breeder, which does limit choices. MSR research has been conducted in Japan, Russia, France, and a couple of other European countries.

  47. Charles,

    Thank you for your prompt and informative reply.

    You state that the IFR has several disadvantages relative to recent EfT design concepts. You move on in your final paragraph to suggest that “the EFT crowd is likely to produce a two fluid thermal fluoride salts thorium breeder, which does limit choices.” Does this indicate that you have misgivings about their likely final design concept? I am also puzzled about your use of the term, “produce”. Does this imply that “the EFT crowd” is in possession of adequate funding to research and develop its preferred design?

    I am not attempting to make snide criticisms, merely trying to understand. If you really believe that an LFTR design can be taken to demonstrator level within a decade given sufficient funding, it may be more sensible for some nations to go directly for this technology and bypass Generation 3. I have read that thermal LFTRs may breed less quickly than fast reactors, but this may not be important in the short to medium term, particularly as they require lower start charges. However, it would seem to be essential that any design that “the EFT crowd ” comes up with should be capable of using used Generation 2/3 fuel or weapons grade plutonium as a start charge and should be capable of modular construction in a factory. Whether it would require graphite moderation or be better without, I am not certain (perhaps you could enlighten me). Also, what proportion of its potential economic advantage would be lost if one were to opt for water cooling and steam turbines as opposed to air cooling, gas turbines and a Brayton cycle (using either helium or CO2)?

    I believe that you have written that the funding needed to get an LFTR to demonstrator level should not exceed 2-3 billion dollars and that you anticipate that commercial LFTRs should be capable of producing electricity at between one half and one quarter of the price of electricity generated by LWRs as well as being very efficient at load following. If what you say is correct (and I would love to believe it), the necessary investment needed to test your belief seems a snip relative to what BP is currently paying out to US litigants to the detriment of British pensioners! Why aren’t investors beating a path to your door?

  48. Douglas Wise,
    “You move on in your final paragraph to suggest that “the EFT crowd is likely to produce a two fluid thermal fluoride salts thorium breeder, which does limit choices.” Does this indicate that you have misgivings about their likely final design concept?”

    No, i favor a 2 fluid design.

    “I am also puzzled about your use of the term, “produce”. Does this imply that “the EFT crowd” is in possession of adequate funding to research and develop its preferred design?”

    This means that one or more funding sources may be in the offing.

    “If you really believe that an LFTR design can be taken to demonstrator level within a decade given sufficient funding, it may be more sensible for some nations to go directly for this technology and bypass Generation 3.”

    There is a real potential for a uranium fueled, transition MSR, that might well compete with Generation III technology before 2020, with a LFTR emerging after 2020. This depends on investment interest. There may be possible military involvement in a near term MSR project.

    “I have read that thermal LFTRs may breed less quickly than fast reactors, but this may not be important in the short to medium term, particularly as they require lower start charges.”

    High IFR breeding rates are not well documented, there are potential safety issues, enough current American weapons grade fissionable material stockpiles and RGP stockpiles are sufficient to start enough LFTRs to produce nearly 100% of American electricity with LFTRs + starting a number of IFRs.

    Graphite is a long, technical topic. Suggest you consult EfT discussions.

    “what proportion of its potential economic advantage would be lost if one were to opt for water cooling and steam turbines as opposed to air cooling, gas turbines and a Brayton cycle (using either helium or CO2)?”
    Efficiency with steam turbines up to .40, efficiency with toping and bottoming cycles + Brayton cycle >.50

    LFTR cost estimates can only be based on a probable cause standard of truth. That is, a reasonable person can believe this, but not “beyond a reasonable doubt. ” Thus LFTR cost estimates are working hypotheses subject to confirmation by further test.

    We have done a remarkable job of bringing the LFTR to the energy table within the last 4 years. Give us a little more time to come up with financial backing.

  49. Charles,

    Thanks again for your further helpful response. I do not doubt that you and your group have achieved a very great deal in a short period and am delighted that sources of funding may be imminent.

    You will realise from my questions that I lack technical knowledge, but would endorse development of both IFRs and LFTRs. However, if low cost electricity is the primary objective rather than long term sustainability (which is apparently an exaggerated issue anyway), it would seem that the latter, if it can fulfil all the claims of its proponents, offers the ideal solution.

    You talk of a uranium fuelled transition MSR as a distinct entity, separate from the LFTR. Is this the chloride fast reactor that you referred to earlier or something else again? (Sorry to be dense). Am I to understand that plutonium wouldn’t be suitable as a start charge and that this transition reactor wouldn’t produce U233 from thorium? I am also wondering why this transition technology would be more likely to satisfy regulators more quickly than would an LFTR. Perhaps ,on reflection, the transition reactor to which you refer is that that has recently been discussed here (molten salt cooled pebble bed as being researched by Prof Peterson?)

    As I come from the UK, I am particularly interested in the use of plutonium as a start charge. We have a 100 tonne stockpile of the stuff which has the potential, I would have thought, to be very valuable, despite the fact that several of our nuclear “experts” would like to render it permanently unuseable.

  50. Douglas,

    The UK plutonium stockpile is sufficient to start up enough LFTRs to replace every plant on the grid, and some to spare. The LFTR breeding rate, doubling every 30-40 years is enough for our consumption growth rate at recent trends, but it is NOT enough to support a rapid transition to an all-electric society at today’s standard of living, which would need something like three times as many reactors. We would need to import the additional fissile as mined uranium, or breed it in reactors with high breeding gain – chloride MSRs or IFRs. Buying it would be cheaper, unless everyone else is trying to do the same thing and drives the price of uranium through the roof.

    The uranium fuelled MSR, sometimes called DMSR, is a version of the LFTR that foregoes breeding gain entirely, in exchange for simplicity and being particularly unattractive to anyone seeking to divert fissile material for weapons. It breeds most of its fuel internally from thorium, but not enough to keep going, and must be fed 500 – 1000 kg per year per 1GW plant of 19%-U235 enriched uranium. (The 19% is because <20% is the internationally agreed limit for enrichment for civilian use). The uranium usage is 5-10 times less than a conventional reactor requires for the same output. DMSRs can also be started up on plutonium, mixed with thorium and some uranium.

  51. Charles, Luke and Barry,

    We could do with a post on BNC that is a dictionary of terms and short description of each relating to the Gen IV technologies.

    Douglas Wise, you could develop it and get the specialitst to review it. You would be better able to write it in a way that is approporate for the non specialists.

  52. Luke_UK, you said:

    Buying it would be cheaper, unless everyone else is trying to do the same thing and drives the price of uranium through the roof.

    I don’t believe the price of uranium will “go through the roof”. The world will always be able to ramp up the rate of exploration and mine development fast enough to provide the uranium the world needs. There ramp rate for uranium demand will be slow and the rate of bringing new mines on will be plenty fast enough to meet demand.

  53. It is not surprising that so little money is being directed into IFR or LTFR research given that coal is so cheap and well understood.

    What is surprising is the huge scale of investments in “Renewables” that have no hope of maintaining even our current industrial society.

    There will be plenty of money for investing in Gen IV NPPs once the ruling elite realizes that they have been scammed by the snake oil salesmen pushing wind and solar.

  54. Peter Lang,
    As you say, the price of uranium will not “go through the roof” owing to simple economics (supply vs. demand). Most of the world’s NPPs “burn” less than 1% of the uranium in the fuel rods but a “once through” cycle is still the way to go owing to the low price of uranium.

    If something happens to make the price “go through the roof” it would favor the development of reactors capable of burning cheaper fuels (e.g. Thorium) and the inventory of nuclear wastes from “once through” reactors.

  55. That is exactly right galloping camel. This is a principal argument I use in my book on this issue — the oft asked questions — if fast reactors are so great, why aren’t we building them today? The three word answer is “history and economics”.

  56. Luke:

    Many thanks for your very clear and concise response which I found enormously helpful.

  57. Peter Lang:

    I think you might be doing BNC readers a disservice in attempting to volunteer me for a role for which I am poorly equipped.

    I repeatedly read about the many different nuclear designs and seem to have grasped the essentials, only to find that, a few weeks later, I have scrambled them all up in my head and have to start again. It may have something to do with senescence/dementia.

    I agree, however, that your suggestion would be valuable, provided a more appropriate author could be identified. Given the clarity of Luke’s response to my, no doubt, naive questions, I believe, should he be willing and Barry agree, that he be saddled with the task.

  58. gallopingcamel:

    You suggest that “once through reactors” are the way to go while uranium remains cheap. You imply that you would only favour the development of Gen 4 reactors when the price of uranium goes through the roof.

    I do not agree at all. Implicit in your statement is a belief or acceptance of the fact that the Gen 4 plants will not produce electricity at a cost significantly below that of current LWRs. I have been encouraged to believe that LFTRs, for example, once developed, might produce electricity at between half and quarter the cost. A second point of disagreement relates to timing. If development is delayed until uranium prices go through the roof ( and you assert that they won’t), then you are tacitly arguing against development at all.

    There is also a third reason to favour rapid development of Gen 4 technology. This is more political than technical. There are many who are anti-nuke on grounds of safety, waste, proliferation etc., whether justifiably or so or not (an irrelevance). A significant number of them could probably be won over by the advantages offered by the new technology.

  59. gallopingcamel:

    Apologies. I misread the final paragraph in your comment to Peter Lang.

    I read “it ” for “I” which led me to infer that you were personally hostile to Gen 4 development. This surprised me in view of various of your earlier comments.

  60. @Douglas, thanks, glad to have helped.

    @Peter, acronyms – the list on the energy_from_thorium wiki, is a start. We need to add more links. It covers some non-thorium stuff too.

    @Peter, uranium price – technically, there is plenty of uranium. politically, mines are unpopular. What restrictions on Australian U mining are the Greens going to demand as the price for their support? Plenty of dumb decisions get made for short-term political gain, happens the world over.

    PS is there an idiots guide to posting on here? For quotes, embedded URLs etc. Yes I have looked on Google, and the WordPress help site? I’m used to bb code – [url=”….”] text [/url]…

  61. Douglas Wise,
    Sorry for not making myself clear. I must confess some frustration to see so much money being wasted on Renewables while funding for workable solutions such as IFRs and LFTRs has dried up.

    On a personal note I used to have a business that supplied instruments for fusion research and would happily jump back on that bandwagon if I thought it was going anywhere in my lifetime.

  62. Acronyms again – 2nd attempt at getting the URL visible

    http://www.energyfromthorium.com/wiki/tiki-index.php?page=Acronym+list

    And if that still doesn’t work, this may be more comprehensible to humans than to the censorbot.

    http://www.energyfromthorium.com_slash_wiki_slash_tiki-index_dot_php_question-mark_page=Acronym+list

  63. Douglas Wise, “You talk of a uranium fuelled transition MSR as a distinct entity, separate from the LFTR. Is this the chloride fast reactor that you referred to earlier or something else again?”

    Something else, a uranium fuel cycle thermal converter that uses fluoride salt coolant/fuel carriers. The advantage would be that all of the technology for such a reactor was tested during the Molten Salt Reactor Experiment. The cost of a uranium fuel cycle reactor would be low, it would have all of the cost advantages of the LFTR, but without the added expense and complexity of breeding. While not offering sustainable technology, it would be very cost competitive with Light Water Reactors, as well as offering outstanding flexibility, rapid deployment, and outstanding safety.

    “Am I to understand that plutonium wouldn’t be suitable as a start charge and that this transition reactor wouldn’t produce U233 from thorium?”

    RGP could be used as a start charge, as could U-235 or a combination. The uranium cycle reactor would not be designed to produce U-233 via a thorium fuel cycle.

    “I am also wondering why this transition technology would be more likely to satisfy regulators more quickly than would an LFTR. ”

    Fewer issues for regulators to consider. And proliferation issues not as complex.

    “Perhaps ,on reflection, the transition reactor to which you refer is that that has recently been discussed here (molten salt cooled pebble bed as being researched by Prof Peterson?)”

    We are talking about a standard MSR design that would be very similar to the Molten Salt Reactor Experiment, but larger.

    “I am particularly interested in the use of plutonium as a start charge. We have a 100 tonne stockpile of the stuff which has the potential, I would have thought, to be very valuable, despite the fact that several of our nuclear “experts” would like to render it permanently unuseable.”

    That 100 tons of RGP could start somewhere between 100 GWs and 200 GWs of MSRs/LFTRs. Not using it to produce energy would be a tragedy.

  64. Thanks again, Charles. I’m learning.

  65. Charles and Luke:

    I’ve been mulling over what you told me and “silver surfing” for further information on the internet. If I may, I’d like to pose further questions to you:

    1) Just as I thought there was but one type of DMSR, (or molten salt converter reactor (MSCR) – apparently the same thing – I have discovered that there are several possible versions (most of this extra information comes from reading David LeBlanc’s writings). I think this may explain why Luke mentioned use of thorium in a DMSR while Charles appeared to suggest a uranium only/no thorium version. It appears that LeBlanc is coming down on the side of the latter as a Generation1 MSR for the following reasons:

    a) More rapidly deployable with less development costs. Cheaper processing compensates for slight impairment of efficiency.
    b) Though we may run out of cheap uranium, we won’t run out of expensive uranium and MSRs could still compete with coal using expensive uranium though
    LWRs couldn’t. Thus neither breeding nor thorium fuel are really needed for a very long period, if ever.
    c) Both types (with or without thorium) could, if necessary, eventually morph into breeders shoud this be deemed economically necessary in the future.
    d) In the medium term the uranium/no thorium MSCR is likely to produce the cheapest electricity available and is likely to be the quickest molten salt cooled reactor to get to market.

    Please could you tell me whether my interpretation of Leblanc’s views is valid and, if so, whether you agree with them?

    I would also like to fly another kite (unrelated to kitegen): I would like to invite your response to the suggestion that “The EfT Crowd” would achieve more by coalescing behind a single, simple MSR concept and forgetting, for the moment, all about thorium. I can appreciate the elegance of the LFTR approach and it’s too good to be true promise, but it would be a pity if, in consequence of the pursuit of perfection, nothing resembling it ever got built. It seems to me that the uranium MSCR might be the most practical first step and it is, after all, an LFTR without thorium, admittedly a contradiction in terms and a possible embarrassment for the Energy from Thorium brigade.

    Given this possibility, could you also comment on why Professor Peterson is trying to establish a PBAHTR? It is not apparent to me what it has to offer over and above that which could be obtained from the uranium MSCR. However, as you are aware, I have no technical expertise and this is why I am asking you for your opinions.

  66. Douglas Wise,
    “Please could you tell me whether my interpretation of Leblanc’s views is valid and, if so, whether you agree with them?”

    Yes, I see the all uranium DMSR as potentially replacing light water reactors as the primary new nuclear technology as quickly as the 2020 to 2030 time frame. They will be cheaper and quicker to build, and more efficient.

    Work should continue to go forward on the LFTR. i regard the DMSR as a transition design. The Liquid Chloride Breeder is a long term project, that requires the same sort of research that underlies the LFTR. Since the required research has already been done for the LFTR, it is more rational to move forward with it in the short run.

    I don’t think that the EfT crowd needs to be embarrassed about being practical.

    i view the PBAHTR as a source of industrial heat. It is a slight variation on the LFTR, with the fuel removed from core salts, and embedded in the core graphite. otherwise the technologies are very similar. Because of the similarities research on the PBAHTR is highly useful to future MSR/LFTR projects.

  67. Charles Barton:

    Thanks for another prompt, concise and informative reply.

    I’ve had one further thought. This relates to the classic LFTR breeder. My understanding is that fuel has to be “regenerated” on site every 10 days or so. How practical is this for the small modular types or even groups thereof?

  68. doug: this question has probably been answered, but where did you find Leblanc’s writings?

    I have seen some of the youtube thorium presentations, but that’s it. (I need to revisit those several times)

  69. Douglas Wise, one of the big advantages of MSR technology is that it opens the door to low cost continuous fuel reprocessing. Engineers will have a range of choices, depending on MSR/LFTR goals, but 2 fluid LFTRs will require less frequent reprocessing and less complex reprocessing, than 1 fluid LFTRs which put everything in the same pot.

  70. Greg: I googled: dmsr and leblanc. This gave me a lot of links. Hope this helps.

  71. It is good to see Leblanc getting some respect here. His two fluid LFTR proposal is impressive for its simplicity. I admire designs that meet the KISS criterion.

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