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  1. Thank you Rod. Terrestrial Energy was founded by Davidv La Blanc, a true visionary, and highly creative scientist. I have written about some ofb David’s ideas in Nuclear Green. The revolution might said to be beginning in Canada. and if we don’t catch up, the Canadians will be comming to eat our lunch in about ten years.

  2. Rod,

    From my chair, I lean back and think about the new Terrestrial Energy’s inexpensive cartridge. The company correctly is keeping much of its design private as it works out a more detailed design, but maybe between us we could speculate about how such a cartridge could be inexpensive. Everything that follows is speculation.

    Let’s assume seven years is the safe life of the graphite but that other materials will also benefit from only 7 years of neutron bombardment and corrosion as well. Instead of enhanced Hastalloy-N let’s use 316 SS which is much less expensive, full code rated, and has supplier experience. The Flouride-salt-cooled High-temperature Reactor (FHR) project is considering 316 SS. My pick for the container and heat exchangers is 316 SS.

    The carrier salt may be a larger expense component than the metal. If FiLiBe is the carrier, both the lithium 7 and the beryllium are expensive. Especially, if they are only used for 7 years. So, is it possible to use a carrier salt that does not contain lithium or beryllium and maintain a good neutron budget? Well, if the cartridge is inexpensive, then lithium 7 and beryllium are not used. I am speculating that the carrier salt is NaF-ZrF4 because this is the least expensive salt identified by ASSESSMENT OF CANDIDATE MOLTEN SALT COOLANTS FOR THE ADVANCED HIGH-TEMPERATURE REACTOR (AHTR). Probably, somewhere in Canada, corrosion tests are being done with the metal-carrier combination candidates.

    Fuel Load
    Delivering a 7 year fuel load would be in the spirit of the sealed capsule approach. So, I think some excess reactivity needs to be controlled. Control rods or a burnable poison could be used. I pick a burnable poison as being cheaper than control rods.

    Rod, do you like to speculate too. Maybe we could start a betting pool.

    1. Martin, my conversations with David suggest that he could very well go with steel for his low cost reactor core. However Stainless Steel has a corrosion problem, especially with Flibe, and possibly with other floride salts. The MSR core is an O2 free environment, so this might not be a problem.

      1. Charles, austenitic stainless steel does not have a corrosion problem in redox controlled fluoride salts. Even without proper redox control (which you would never do) the corrosion rate is perfectly acceptable, especially for 7 years or so.

        The stainless steel corrosion thing is a myth. Corrosion of austenitic stainless steels in fluoride salt is caused by incorrect design and operation: impurities in the salt, incorrect redox operation, dissimilar metals in the salt (galvanic corrosion), excessive residual stress in welds, etc. All of these can be avoided.

        1. Cyril,R., the corrosion problem in the ORNL MSRE involving the Chromium in the Nicole alloy used in the core. It was a small problem after 20,000 hours of reactor operation, but it would grow over time. However I suppose that the 7 year core life span probably would not pose a serious chromium corrosion problem

          1. Charles, there wasn’t a chromium corrosion problem in the MSRE. There was only some fission product tellurium attack of the grain boundaries. More chromium reduces this attack, so stainless steel ends up doing better than Hastelloy N.

            Also, the tellurium attack was increased by the oxidizing redox window of the MSRE. It operated on U4/U3 ratio of 100, a real reactor would operate near 50 or so (below 70 is no longer oxidizing).

    2. I would think that the fuel salts would be drained and re-used in the new core. Is there a reason why this would NOT happen?

  3. Rod – Thank you Thank You !! for posting this talk. I have been following molten salt, Kirk Sorensen, and all the usual suspects for several years now. This is tremendous news, and especially because it’s aimed at an economic community, not simply a technical one.

    The questions and answers are particularly well chosen; I’m sure there were more than are shown. Martin Wash (if I caught that right) asking about the Wigner effect on graphite at 23:27 shows that this is a technically savvy audience. The analyst asking about potential markets, and MacDairmid’s answer about addressing vertical markets with industry partners… then about Terrestrial Energy’s financing plans. Terrestrial is talking business!

    @martin burkle – if you go back to David LeBlanc’s various presentations at thorium conferences, he talks about adding top ups of fissile to the reactor as time goes by. That sounds like simpler reactivity control than burnable poisons and other methods. (I borrowed the textbook Introduction to Nuclear Engineering from the Calgary Public Library and read it to help me understand more of the discussions. It makes me appreciate the simplifications made possible by molten salt fuel even more. I also spotted several things that anti-nuclears could use as talking points, if only they’d take more time to understand their ‘enemy’. It’s amazing what you can find at the library…)

    I also have to say that the Terrestrial Energy team makes me proud to be Canadian. I think we can all get behind MacDiarmid’s goal to “shift the narrative to an aspirational level.”

    Thanks again, Rod.

  4. Thanks for posting the video on the Molten Salt reactor.

    Here’s a generic question. I’ve watched the video you posted, the great videos by Gordon McDowell, read most of Mr Hargrave’s book and other information. I’ve seen no valid criticism of these reactors. They look like they could be a money maker in the long term. How come the big energy companies in the US and maybe Europe aren’t developing this thing? Even with the better financial return from oil, coal and natural gas, there will be a time when these are once again in less abundant supplies.

    1. GE and Westinghouse have a business model that assumes regular sales of fuel for their existing technology. The molten salt reactors are so efficient that they would destroy this business model by only requiring 5 to 10 percent of the fuel the water moderated reactors do.

      Basically it comes down to money.

      1. There is some money from fuel fabrication contracts but we shouldn’t exaggerate this.

        A large reactor might pay $10 million/year for fuel fabrication. And maybe another $20 million for enrichment and uranium fuel itself.

        But that same reactor has over $2000 million worth of equipment and a similar or larger amount in engineering services, installation, commissioning etc.

        So I think that supplying the equipment in a rapid buildout situation is a lot more attractive as a business than selling fuel. Selling fuel is a nice bonus but not a growth market.

    2. Eino – that has puzzled me as well. And the best answer that I’ve come up with is that it really takes a visionary business leader to break out and do something different. I don’t think anyone really has seen the big picture yet.

      What big picture? My answer to that is that the energy and fuels business can be 25x bigger than it is now before we have to think about physical limits. The physical limit I have in mind is that all of our fossil, nuclear and geothermal energy use adds heat to the atmosphere. (Geothermal brings heat out of the rocks ‘before its time’, so to speak – before it would leak out through the intervening rocks.) Hydro, wind, and solar come from the immediate solar energy striking the Earth; we just shift them around a bit.

      The vast majority of the energy in our fuels winds up as heat added to the atmosphere. This has the same effect as adding greenhouse gases. I don’t have the citation, but IIRC the climate models say that 1 watt per square meter of additional heat on the earth’s surface results in 0.8 degrees C rise in the global average temperature. I think Rod said in one of his Amory Lovins posts that Lovins was worried about this as well. I haven’t done any research to see if Lovins did any arithmetic to see how worried he should be.

      If we decide to limit our fuel-induced climate forcing to 1 degree C, that means we have a budget of 1.25 watts per square meter available to us. Earth’s surface area is about 5.1 x 10*14 square meters, so we could set ourselves a ceiling of about 6.4 x 10*14 watts for primary energy use.

      That’s a lot. That’s a primary energy budget of 90 kilowatts per capita for a global population of seven billion, or 64 kilowatts for the 2050 forecast population of ten billion. From the BP statistical review, average per capita primary energy consumption in 2012 was about 2.4 KW per capita. Depending on which numbers you use to compare, that’s about 25 to 38 times more energy – and hence, more fuel and a bigger business.

      What’s holding people back is that it would be a vastly different business. If we’re using uranium and thorium in burner and breeder reactors to get more than 90% of the energy out, as we should be, all of the 2012 primary energy would be supplied by less than 7,000 tonnes of fertile and fissile nuclides. Moving away from massive mining and extraction industries will ‘break a lot of rice bowls’. You may have seen the Australian coal miners union advertisements opposing nuclear power; that’s the least of the opposition.

      “Shifting the narrative to an aspirational level”, as MacDiarmid said, what could we do with a power budget of 64 to 90 KW per capita? We’d have to budget some for activities to manage the earth’s climate. And what else? Could we cope with prosperity?

      But back to a visionary business leader (it’s definitely not me!) – someone in the hydrocarbon fuels business just might realize that Terrestrial Energy’s ‘heat batteries’ (which calls up an image of an energizer bunny banging a conventional atom as it just keeps running) can power a manufacturing facility that takes current industrial CO2 waste streams (from cement manufacturing or CO2 removal from natural gas), combines it with hydrogen produced using TE’s heat, and generates fuel that can be sold into the existing infrastructure, and can be promoted as ‘green’, benefiting from ‘hysteria about climate change and CO2’ (even if the business leader doesn’t think the concerns are valid)… If the fuels business leaders decide it’s in their interests to promote molten salt reactors, I think we just might see some action. That’s one of the reasons I was so pleased to see Terrestrial Energy promoting to the business and financial community. I think it was Joe Sestak in his presentation to TEAC 5 in 2013 who said, “Doing good is not a business plan.” It’ll be good to see nuclear reactors making it into business plans.

      As Rod has been tracking on Atomic Insights, the entrenched fuels interests have been keeping the lid on nuclear fission. The liquid fuels businesses could break away, leaving the coal interests alone. We live in very interesting times.

      1. The vast majority of the energy in our fuels winds up as heat added to the atmosphere. This has the same effect as adding greenhouse gases. I don’t have the citation, but IIRC the climate models say that 1 watt per square meter of additional heat on the earth’s surface results in 0.8 degrees C rise in the global average temperature. I think Rod said in one of his Amory Lovins posts that Lovins was worried about this as well. I haven’t done any research to see if Lovins did any arithmetic to see how worried he should be.

        I think you’re on the right track here, but adding heat to the atmosphere (or ocean) from fuels has the same effect as adding greenhouse gasses only to the same effect as that “same effect” is a rise in temperature. You can express both as thermal forcing. At present the forcing from ghg is about 4.5 W/m^2, that from all our fuels about 0.1 W/m^2 — just barely detectable, with a delta T of 0.08 C. Quadrupling energy consumption to bring everyone to EU standards would be 0.32 C, octupling to get NA profligacy, 0.64 C. We could increase fuel energy twelve-fold and remain within 1 C rise from that source, about half your estimate but a lot of power either way. Plenty enough to start putting some of that 4.5 W/m2 (1.9 from CO2 alone) toothpaste back in the tube, should we care to do so.

        How can we do that? One obvious way is biomass combustion with CCS. What are its limitations? Well, growing and harvesting biomass can be fossil-fuel intensive, the harvesting part would have to go electric or low-carbon synthetic gas. Then there’s soil carbon depletion so you want to limit where and how much you harvest. Over a long time period it could add up, but the question is how long time do we have. How can we sequester CO2 from the atmosphere or ocean directly, how much energy will that take?

        I’m thinking underground quarrying of limestone, on pretty massive scale, then thermal decomposition to CO2 and quicklime. The CO2 would be in a fairly pure stream and be sequestered in depleted oil&gas fields. The quicklime (Calcium oxide) could then be used to react either atmospheric CO2 with water to form calcium bicarbonate which could then be thermal-cycled back to captured CO2, quicklime, and steam, or the quicklime could be reacted with ocean water to capture the CO2 there as bicarbonate, where it would probably have to stay.

        We need numbers for this, surely its been well studied. Mining is electric intensive, no problem there. Thermal decomposition of limestone could be either nuclear or concentrated solar, depending. Questions are how rapidly one can react atmospheric CO2 or ocean water with quicklime, what would the reactor vessels look like, and how large. You might be able to evaporate ocean water after reaction with quicklime to collect and recycle bicarbonate, reduce the required mined limestone volume, but that will take even more energy. Where will it all come from? Is there enough sunshine? And if you do, there’s still uranium left in the salt residue. Talk about toxic waste: will the NRC clear it? And all that desalinated waste water — what could we possibly do with it?

        Perhaps we should just leave the CO2 where it is and learn to coexist. Its organic, you know 😉

        1. @Ed Leaver

          Why not imitate, but accelerate natural processes? We could increase planting and enjoying trees and other beneficial biomass. When they have reached full maturity and begin to exhale as much CO2 as they consume, harvest them and bury them beneath layers of soil or underwater, sort of like nature apparently did during the Carboniferous Era and like the way it has apparently created our current stores of hydrocarbons over time.

          In a primarily fission-powered world, we don’t need the energy from burning it as biomass, and the burying scheme would most likely require less transportation and other infrastructure than direct consumption as biomass fuel. It will be a slow process in restoring the natural balance, but what is the rush? Humans should plan on inhabiting this planet for many millennia to come.

          1. @Rod Adams
            Ideally I’d agree 100%. Times are not ideal: what humans should plan on and what we have actually planned for are two different things. At 400 ppm CO2 we’re already well past the 350 ppm considered sustainable, and show no indications of not shooting through 550 ppm and above. This is not good. There are tipping points. Toothpaste is out of the tube and we’re going to squeeze a whole lot more before a global low-carbon economy can take hold. When it does and there is plentiful energy for all then yes: reforest and re-prairie and pay our farmers to maximize carbon retention and… will it be enough soon enough? I don’t know, is why the interest in artificially enhanced toothpaste recovery.

        2. Biomass is backwards. We’ve been there as a species and got the scars. Suggesting we increase usage of biomass for lowly energy purposes is a good example of bad resource management.

          The strength of biomass is in the complex chemical bonds that can be made. It is a good specialty chemical and material application. Even for those applications it is doubtful that enough supply is available, in sustainable terms.

          Biomass is fundamentally limited by energy density. In a world that used 1% the energy of today, it was barely acceptable. In today’s world that is rapidly increasing its energy usage even with the best of energy efficiency technology, biomass energy is at best a tiny useful niche and at worst a dangerous distraction.

        3. Ed Leaver, from this —

          I’m thinking underground quarrying of limestone, on pretty massive scale, then thermal decomposition to CO2 and quicklime. The CO2 would be in a fairly pure stream and be sequestered in depleted oil&gas fields. The quicklime (Calcium oxide) could then be used to react either atmospheric CO2 with water to form calcium bicarbonate which could then be thermal-cycled back to captured CO2, quicklime, and steam, or the quicklime could be reacted with ocean water to capture the CO2 there as bicarbonate, where it would probably have to stay.

          — it sounds as if you are about where I was when — under the name “Burn boron in pure oxygen for vehicle power” — I wrote the seven comments at

          I suppose if the subject has been reintroduced there the same things have been said again, no-one having learned anything.

          However, I have since learned that there’s plenty of naturally-occurring base with which to neutralize and precipitate atmospheric carbonic acid, aka CO2, so we don’t have to make CaO for this purpose.

          The naturally-occurring base is magnesium orthosilicate, Mg2SiO4, and similar materials such as serpentinite and wollastonite. You can get started on this at and find a longer treatment at .

          The upshot: all the chemical steps (all one of them) are exothermic and spontaneous at room temperature, and a trillion tonnes of CO2, precipitated on ten percent of the planet’s surface as magnesite (MgCO3) over a multi-year period, would be unobtrusive. (Actually, the whole ~2 teratonnes would not accumulate as solid particles. It would run into the sea as dissolved bicarbonate. But if it did so accumulate it would be unobtrusive.)

      2. Better, capture the CO2 waste stream from cement and sequester it. And steel too if you can do it. Then electrolyze seawater. On a massive scale. Wind and solar PV can help. The cathode will collect hydrogen, the anode CO2 and oxygen. Membrane separate them. Sell the hydrogen to fuel cells. Sequester the CO2. Profit!

        1. taking an idea from Weinberg, how about a large nuclear park on the coast of a desert country. In my mind the park could be made up of reactors doing two primary things and two secondary things. Primary function from the high temp heat would be electricity and synthetic fuel production with reactors dedicated to each. The ratio would be dependent on location and need. Their waste low temp heat could then be used to do two things, desalinate water to irrigate the dessert surrounding them, whilst the remainder is used to be the driving energy behind air cpture of CO2. such a function requires a lot of energy however it can be low grade which fro electrical production you should have a lot of. The CO2 is then used in the synthetic fuel production effectively trapping it in liquid form.

          The final element would be where ever possible the synthetic fuel wouldn’t be completely burnt instead rather like the old way of producing town gas from coal the fuel is cooked in coking oven to release the trapped hydrogen which is then burnt for whatever is the required process far away from the reactor complex the Carbon is then retrieved and can be used as a base material for structures (carbon fibres etc) and more importantly sent back to he desert where we have our country with its nuclear complex and used on the land to upgrade the soil permanently sequesting the carbon whilst giving a commercial use through better crop yields

          1. Synfuels are the right direction for energy independence. Their cost is directly related to the cost of the materials input and the cost of the energy. The Navy design was estimated to cost around 2.50 to 3.50 / gallon using CO2 from water and electricity from the onboard NPPs. With high temperatures and a cheaper source of carbon these costs could be driven down even more. I have read estimates of coal to liquid fuels at about a 50 / barrel cost. This is competitive. With a very cheap source of heat I believe that cost could be even lower. Many wells today are costing 80 / barrel to pump.

  5. I like there approach. it is complete customer focused approach which is something the nuclear industry has never done. there has always been a disconnect with new reactor technology and the end user, LWR were developed to power ships and then modified for power production. Gas cooled similar but for plutonium production, and the LMFBR was purely a misguided assumption by the scientific community that uranium was rare and therefore we need breeder reactors with high doubling time (hence maxing breading ratios).

    Non of the above met the operators need of simplicity, low cost and simple construction, and short financeable construction schedules. End users have never been concerned about waste (small amount of the cost of operating and is a operational cost not a upfront cost) or decommissioning (end of production so easy to pay for) or fuel scarcity (uranium has a high level of resource security compared to almost any other resource) all of which governments and as a result venders have been trying to address. Here finally is a company who understands this and is designing a product to suit. as a result I can only think that they will have a huge amount of success and could change the world.

  6. This is the most exciting new technology in the nuclear industry that I have seen in a while. If they can do what they say, this design could actually be a game changer. I hope they succeed and break ground on their prototype plant within the next decade.

  7. Sorry for the late posting but I found two points of interest in Mr. MacDiarmid’s presentation. First that the company is going through the Canadian nuclear regulators. Second that the design uses graphite as the moderator rather than going the fast reactor route.

    While some might think they are separate, I wonder if the reason for going the Canadian certification is more from the design likely having a net positive reactivity coefficient from using the graphite. Such a reactor design would not be allowed by the U.S. nuclear regulators. If this is the case then why didn’t Mr. MacDiarmid mention this as the reason for staying with the Canadian nuclear regulators? It’s a retorical question, so no need to reply….

    1. @Flying Finn

      The reactors that have an issue with positive reactivity coefficient are SOME water-cooled, graphite-moderated reactors (unmodified RBMKs). The molten salt graphite-moderated reactors that Terrestrial Energy is designing have a strong negative coefficient of reactivity.

      1. So do CANDU reactors. Not saying you are wrong, but I would like to see some proof of the core neutronics and material properties/responses (i.e., physical response in the graphite or fuel [density] such that enough expansion for a set delta-T leads to a non-critical configuation).

        Do you have a paper to point to? I’ll check the Terrestrial Energy, Inc. website but if you have something readily available, I’ll know the source of the info….

        1. Found the answer at

          MSRs have large negative temperature and void coefficients of reactivity, and are designed to shut down due to expansion of the fuel salt as temperature increases beyond design limits. The negative temperature and void reactivity coefficients passively reduces the rate of power increase in the case of an inadvertent control rod withdrawal (technically known as a ‘reactivity insertion’). When tests were made on the MSRE, a control rod was intentionally withdrawn during normal reactor operations at full power (8 MWt) to observe the dynamic response of core power. Such was the rate of fuel salt thermal expansion that reactor power levelled off at 9 MWt without any operator intervention.

          Thanks for the feedback.

  8. It seemed to me that visionaries such as David LeBlanc and Kirk Sorensen would have to emigrate to see their ideas implemented.

    It is encouraging to find that at least David LeBlanc won’t have to relocate.

    1. @gallopingcamel

      Of course, David is already a Canadian citizen and resident. He lives in a place where regulators like Michael Binder recognize that their assigned mission is to regulate radioactive materials to protect the health, safety and security of Canadians and the environment. It is NOT to bow down to political pressure from competitors to make it as expensive and difficult as possible to use nuclear energy.

      Binder diligently communicates his agencies responsibilities and directly refutes the attempts by activists (who often are carrying the water of energy production competitors) to use the rules to delay projects and add costs.

      He also shuts down meetings in which activists misbehave.

      1. Michael Toledano’s reporting appears to be biased. Too bad he does not realize that the activists don’t have a scientific leg to stand on. For example the statement attributed to Gord Albright was total BS and yet it got reported as if is was revealed truth.

        My first encounter with uranium was at Chalk River in Canada in 1973. During a tour of the research facility a piece of a fuel rod was handed around, so I asked whether it was a dummy. It contained real uranium so it was a surprise to find how low the count was on a Geiger counter.

        I hope your “Small Modular Reactor” is progressing as planned so you won’t have to relocate!

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