Molten Salt Nuclear Reactor that will make nuclear as cheap as natural gas passes first certification hurdle

Terrestrial Energy’s Molten Salt Reactors completed phase 1 of the vendor design review – the first advanced reactor to do so – is a landmark achievement. It places the company as an early leader in a fast growing technology sector. The IMSR nuclear power plant is a transformative energy technology that is now one step closer to making a major contribution to the world’s growing demand for low-cost, clean and reliable energy.”

The Vendor review involves three phases:
1. a pre-licensing assessment of compliance with regulatory requirements;
2. an assessment of any potential fundamental barriers to licensing; and
3. a follow-up phase allowing the vendor to respond to findings from the second phase.

Terrestrial Energy’s Integral Molten Salt Reactor (IMSR®) is designed to meet the rapidly rising demand for breakthrough energy technologies that can deliver clean, scalable, and cost-competitive heat and power to displace fossil-fuel combustion starting in the 2020s. The IMSR® is a fundamentally different reactor. It employs advanced molten-salt technology, which creates a far superior system to harness clean bountiful energy of the atom simply, safely and economically.

IMSR® power plants are far simpler to build and operate than conventional nuclear power plants. They cost less than USD $1 billion, can be built within 4 years with much lower project risk, and can be financed by ordinary means.

IMSR® power plants are low-risk and cost-competitive clean-energy alternatives in North American and many other markets. In electric-power markets, IMSR® plants can dispatch power at under USD $50 per MWh (levelized cost), cost-competitive with NGCC for power generation, and probably more so with a volatility-adjusted price of natural gas; they are more cost-competitive when compared to coal. In industrial heat markets, IMSR® plants are also cost-competitive with natural gas; they have an in-furnace cost of less that USD $6 per MMBtu, within USD $1 of current in-furnace natural gas costs.

Using advanced molten salt reactor technology, IMSR® power plants are simpler than the Conventional Reactor power plants in the market today, which are pressurized-water reactors. IMSR® power plants are smaller, and with modular design and construction, can be built within 4 years and financed by ordinary means. IMSR® power plants will be cost-competitive with fossil fuels even in the absence of CO2 emission penalties.

Molten salt reactors use fuel dissolved in a molten fluoride or chloride salt which functions as both the reactor’s fuel and its coolant. This means that such a reactor could not suffer from a loss of coolant leading to a meltdown. Terrestrial’s IMSR integrates the primary reactor components, including primary heat exchangers, to a secondary clean salt circuit, in a sealed and replaceable core vessel. It is designed as a modular reactor for factory fabrication, and could be used for electricity production and industrial process heat generation.

Earlier this year, Terrestrial Energy began a feasibility study for the siting of the first commercial IMSR at Canadian Nuclear Laboratories’ (CNL) Chalk River site. It has also said it intends to submit an application to the US Nuclear Regulatory Commission for a design certification or construction permit in late 2019.

The Canadian Nuclear Safety Commission (CNSC) has completed the first phase of a vendor design review of Terrestrial Energy Inc’s Integrated Molten Salt Reactor (IMSR).

The CNSC announced yesterday that, based on the documentation submitted by Terrestrial Energy, the company had demonstrated an understanding of the regulator’s requirements applicable to the design and safety analysis of the 400 MWt IMSR, known as IMSR400. The company has also demonstrated its intent to comply with CNSC regulatory requirements and expectations for NPPs, and is integrating Fukushima lessons learned into IMSR design provisions, the regulator said.

Terrestrial Energy will need to undertake additional work to address some of the review’s findings, including the need to establish robust quality-assured processes for design and safety analysis activities.

Several features are currently at the conceptual level of design and will require additional technical information, based on research and development and design activities, the CNSC said, while some design features will need further consideration because of the novel design of the IMSR400.

Further work will be needed to predict core behaviour in the presence of damaged core components – although the CNSC acknowledges that the definition of core damage as set out in current regulations, which were drawn up based on operating experience from water-cooled reactors, may not be applicable to the IMSR design. Terrestrial Energy will also be required to complete further safety analysis work relating to core damage, and to provide further information on how it will validate predictions of performance as the reactor ages.

In the second phase of the review, Terrestrial Energy will also be required to demonstrate that human factors in design have been appropriately addressed in its operability and maintainability programs, which are currently under development.

The IMSR® is a liquid-fuel reactor system, rather than a solid-fuel system, as is used exclusively in conventional reactors. The IMSR® dissipates heat using a molten salt. Salts are thermally stable and excellent heat-transfer fluids, ideal for dissipating heat from the fission process simply and safely. In a molten salt reactor (MSR), salt provides a fluid medium to carry a nuclear fuel—in the case of the IMSR®, a low-enriched-uranium fluoride salt. The IMSR® provides simple, safe, and natural mechanisms for heat dissipation. It is a far superior system for the simple passive dissipation of fission heat. The use of a molten salt is at the heart of many engineering and commercial virtues of the IMSR®.

An IMSR® power plant generates 400 MWth of thermal energy (190 MWe) with a thermal -spectrum, graphite-moderated, molten-fluoride-salt reactor system, fueled by low-enriched uranium (less than 5% 235U). It incorporates the approach to MSR design and operation researched, demonstrated and proven by the ARE and MSRE test reactors at Oak Ridge National Laboratory (ORNL); these were further developed under the DMSR program.

The IMSR® improves upon the earlier ORNL MSR designs through various innovations that are pragmatic and commercial. The key challenge to MSR commercialization is graphite’s limited lifetime in a reactor core, which is a function of reactor power. Commercial power reactors require high core energy densities to be economical, but high power densities significantly reduce the lifetime of the graphite moderator requiring its replacement; this is challenging to do simply, safely and economically in an industrial environment. The key IMSR® innovation is an elegant solution to this challenge – the integration of the primary reactor components, including the graphite moderator, into a sealed and replaceable reactor core, the IMSR® Core-unit, which has an operating lifetime of 7 years. The IMSR® Core-unit is simple and safe to replace, it supports high utility factors for IMSR® power plants and high capital efficiency. It also ensures that the materials’ lifetime requirements of all other reactor core components are met; the challenge of achieving these requirements is often cited as an impediment to immediate commercialization of MSRs. The result is a power plant that delivers the combination of high energy output, simplicity and ease of operation, and cost-competitiveness essential for widespread commercial deployment. IMSR® power plants are a new clean energy alternative.

46 thoughts on “Molten Salt Nuclear Reactor that will make nuclear as cheap as natural gas passes first certification hurdle”

    • It would be much easier to get licencing for a reactor that uses existing reactor fuel than to convince the authorities about a completely new tech using a fuel that is also completely new.

      Thorium is doing things the hard way.

  1. The Fed’s estimates of cost of energy are not realistic – non-dispatchable power sources require back up generation which cannot operate at anywhere near their efficient capacities and also require enormous tracts of land for siting – which is often not paid for. The several molten salt reactor designs differ rather significantly in their strategy, althoug they all are immune to practically any conceivable disaster. There are no pressures associated with the radiactive sections of the plant and the fuel is extremely proliferation resistant and any contact between the fuel and external air temperatures (because of an unlikely leak in the vessel) would immediately freeze the molten salt fuel and it would drain away from the moderator, which would halt the fission process. I fel that the design by Moltex Energy is probably the most cost effective and one that could commercialize the soonest, as it employs existing components.
    Their estimated LCOE is cheapest of them all, at less than $35 per mWhr, making it the cheapest of all power generators and , like all molten salt reactors, has a very small environmental footprint – wind farms require thousands of times more land. Unlike conventional reactors, these reactors can load follow,
    which allows them to be both base load generators as well as peak load generators, eliminating the need for fossil fuel generation, in large measure. The future of energy is molten salt nuclear. The Chinese and Indians know this, and are developing molten salt reactors themselves. Any country that thinks it can thrive on renewable wind and solar wil be at a distinct economic disadvantage. The Chinese have already banned wind turbines as “disruptive to the electrical grid.” Are we going to allow the Chinese to
    obtain yet another economic advantage over us? Renewable folks are religiously motivated lairs, by and large, who foolishly are attempting to reduce the atmospheric CO2 levels, potentially a real looming mega disaster.

    • The Chinese and Indians know this, and are developing molten salt reactors themselves.

      It is pretty obvious that PWRs will be the mainstream but not sole reactor type in China. “Beyond them, high-temperature gas-cooled reactors and fast reactors appear to be the main priorities” (WNA). India’s small fleet consists of heavy/light water reactors. These countries are certainly not at the forefront of MSR technology.

      Instead of being frustrated by your confident ignorance, I have to remember that I could actually be spending my time correcting a 14 year old or a DMV clerk that builds model airplanes and watches discovery channel programs narrated by Morgan Freeman in his free time.

  2. Using thorium, mobile units could power cities of 100k. Thorium can be contained in the event of loss of coolant since it only reaches 5,000 degrees F. Making the switch to this more plentiful and safer alternative than Uranium or Plutonium would be safer and more cost effective. Besides, thorium cannot be weaponized. Thorium ore also contains rare earths and valuable metals needed for lithium batteries, super magnets, LED screens , and many other vital uses.

    • Dude, do you have a frame of reference of what 5,000 deg-F is? It is about 50 degrees higher than the BOILING temperature of nickel. Your statements are not even wrong; peak temperature is a function of assumptions.

    • True, as far as Thorium does not sustain a chain-reaction of itself, and is not sufficiently radioactive to make a dirty dust weapon of any consequence.

      Thorium is useful to breed U-233 which is the desired fuel. One can use 233 for bombs, but it’s use comes with handling problems; and, if one already has a neutron source, plutonium poses less issues.

  3. This design is a continuation of huge centralized electrical production fraught with power failures resulting from storms and other causes! It will never become a reality because of distributed power generators such as ecat and suncell!

  4. What a load of rubbish

    This is what they said about nuclear reactors now they cost us all billions and that’s when they are no longer being used

    Wang is an liar or an idiot…ether way he his making the rich richer and the poor live in hell

    • Why? This technology offers the poor of the world a chance at electricity use round the clock, every day.
      I beg you Tom, do some reading on these reactors. At one time I read they were planing on “burning” waste from current generation nuclear plants.

    • Wang is not a liar, he recycles PR from companies, and perhaps adds his own flair, and makes money off it. The stuff however does not originate with him, but with some organization/company.

  5. I’m hoping this gets done. We need a solid alternative source of energy rather then fossil fuels. This is one idea even if it costs more, but has no pollution foot print.

  6. Good for Canada. They have a nuclear regulatory commission getting the job done. Regardless of whether the plant can produce energy at that price point, at least they get to build the thing. That’s more than can be accomplished here in the U.S. with all this well funded NIMBY protesting. Sometimes when you build something, even if it doesn’t work as promised it can lead to ideas that create disruptive technology breakthroughs. If you don’t allow people to build it, even commercial failures, then we go nowhere.

    • Canada doesn’t have Greentarded NIMBYism? There’s a Keystone Pipeline being built because BC refused to allow it built to Vancouver that kinda proves that wrong.

      And I doubt that BC or Ontario or Quebec voters would tolerate even one of these babies being built in their provinces anymore than the Greentards in California would in their state, either. It is EVIL NUCLEAR, you see.

    • Lol, would you like to compare the damage done by coal fired plants to nuclear? Guess which one releases more radioactive materials, not to mention the rest of the toxic materials, and kills more people? I guess we could always revert to whale oil lamps…

      • The math that says it kills more people is being exposed as a false calculation. Linear no-threshold relationships for dilute pollutants is not physically real. For instance, the coal plant releases XX tons of YY. We know that an acute dose of ZZ of substance YY is lethal or could lead to cancer. The linear no-threshold math scales the acute dose to the extremely dilute dose and they report that 50 people out of a population of 330 million americans will die from release of substance YY. Extremely flawed math.

        • So, would you agree that pregnant women should eat albacore tuna? I have some GREAT land right next to 3 coal fired plants. It’s a great deal! Would you like to live next to them, considering that it’s all just faulty math?

          • This is a UN report backing me up with regards to radiation dose.


            Here is a meaty excerpt (a tall glass of shut the hell up):

            “In general, increases in the incidence of health effects in populations cannot be attributed reliably to chronic exposure to radiation at levels that are typical of the global average background levels of radiation. This is because of the uncertainties associated with the assessment of risks at low doses, the current absence of radiation-specific biomarkers for health effects and the insufficient statistical power of epidemiological studies. Therefore, the Scientific Committee does not recommend multiplying very low doses by large numbers of individuals to estimate numbers of radiation-induced health effects within a population exposed to incremental doses at levels equivalent to or lower than natural background levels…”

            Yeah, it would probably be hard for a pregnant woman to eat enough tuna to make the kid a retard. I ain’t no OBGYN nor am I a radiation oncologist, but I laughed when the dentist didn’t want to x-ray my wife’s teeth when she was pregnant.

        • I wish you could get that thought out to the general public and government agencies .
          Still the thought of a pollutionless power generation unit sounds better than clean coal

    • No the safe part of molten salt reactor is the salt, not the thorium. In a Thorium powered reactor Thorium is transmuted to Uranium 233 and then fissioned.

      • The Protactinium intermediate must be chemically separated periodically for economically breeding 233. Nice to potentially have weapons grade material from a chemical process. U 232 salting to the rescue?

        • You mean 238U and it’s called denaturing. The real problem is that 232Pa decays much faster than 233Pa so if you just let everything sit in your drain tanks for a couple of months yoi can basically get isotopically pure 233Pa which then decays to 233U and you’ve got your bomb. And denaturing doesn’t really help that because you take off all of the uranium before the first step.

          A 235U burner doesn’t have that problem because you can’t separate the 235 from the 238 chemically.

  7. Nuclear is on my opinion the energy source of the future. Most probably the MSR is the reactor concept of the future. What I do not like are are selective phantasy articles.

    When I as an engineer with decades of experience in the chemical industy calculate a nuclear power plant from that view it might cost 1.5 – 2.5 billion $ for 1200 MWe PWR. The reason for the high costs of new nuclear power plants are extreme requirements on certification of contractors, materials. Requirements on testing and documentation that are not in line with the low risk of a nuclear plant.
    In reality the same requirements that are put on PWR reactors will be put on MSR as well. The MSR looks more complex uses more expensive materials and hence should be more expensive than a PWR.
    On my point of view nuclear industry should word on the real challenges first instead of writing optimistic articles.

    • Nuclear is on my opinion the energy source of the future.

      Nuclear fission is indeed the energy source of the future and today.

      • $50/MWh leveled cost is not competitive in North America at the moment. The construction costs here, at the 2nd largest nuclear station in the USA (3.6GWe net), have been long paid off, although there continues to be capital investment. At the moment, we are not competitive at $30/MWh (PJM locational marginal pricing was $29 with a STDEV of $16 in 2016). Granted, we have a lot of workforce bloat, including engineers that comment on blogs during working hours, but still way under $50/MWh.

        Depending on the amount of head-room in this sealed core can, we can expect it to pressurize quite a bit. A plain fuel rod with about 5% head room above the fuel stack will pressurize maybe 7 atmospheres over its lifetime and that is with much of the gas trapped inside the ceramic pellet. If one rod pops in an LWR it is not a catastrophe, but it does incur costs in the millions of dollars for the operator. When the penetrations in the sealed can of this MSR (for the secondary loop, instruments, etc.) leak, then the whole inventory of gas is in the reactor building and your staff starts typing new resumes.

        Salts are thermally stable and excellent heat-transfer fluids…

        Pulling that thread, I find that it has a thermal conductivity of (Pu(x)U(1-x))Cl3 is nearly equal to water, which is about 1% as good as sodium; the heat capacity is listed at about 20% of water. Let’s not espouse its thermodynamic properties as “excellent” when they simply are what they are. Also, the Oak Ridge MSR fuel was found to have fluorine gas in the headspace of the spent fuel storage canisters; it was not expected because of the fuel’s “stability”. Chlorine bonds are probably weaker than fluorine bonds, so we can expect the fuel mixture to give off chlorine, which Fritz Haber weaponized for the Jerkmans in WWI.

        As for the Canadian licensing efforts, no matter how well funded Terrestrial Energy is, I repeat myself:

        MSRs are not high tech; they are in fact low, low, tech (as low tech as a bucket). The lack of fission product retention is a fundamental MSR design problem, which coincidentally is the reason we don’t already have a fleet of these otherwise exceedingly simple devices. The various MSR groups need to consolidate and push for a modest pilot plant with a cradle to grave plan for no more than several tons of fuel salt. They can build from there after they demonstrate the materials, offgas handling, long term spent fuel storage. If they can demonstrate good handling and effective reprocessing on a laboratory scale, then lobby to bring the tech into production. There is only so much experience that can be leveraged from the Oak Ridge experiment, which although regarded as a success, exposed quite a few design problems and resulted in quite a costly cleanup. There is no infrastructure for this fuel product and storage of spent fuel has been a problem. Include construction of the infrastructure and see the cost estimates rise.

        • Natural gas in the US is cheap enough that really nothing competes with it.

          The MSR being simple is really a compliment. My 03 Honda Accord was simple.

          They are quoting prices ($50/MWh) based on steam turbines. If we can ever get supercritical CO2 turbines then the price will drop as the efficiency improves.

          My recollection was that the Oak Ridge MSR free flouride gas problem was solved by reheating the molten salt.

          I have wondered if the gassing problem can be mitigated by starting the fuel in the MSR “pressure vessel” in a vacuum. Either way the pressure vessel is in a sealed enclosure and they should plan for a possible leak.

          Yes we desperately need a pilot plant.

        • Just a clarifying detail… the specific heat of uranium tetrachloride is 20% of water, but it is 5 times more dense so the volumetric heat capacity is equivalent to water.

    • An MSR like Terrestrial Energy’s is less complex than a PWR, can be mass-produced in a factory, is cheaper to construct because it operates at atmospheric pressure, and doesn’t need a huge containment dome because it uses a coolant that won’t expand its volume 1000x if there’s a pipe break. There’s nothing to drive a chemical explosion either.

      PWRs, especially GenII, rely on complex, redundant active safety features. MSRs do just fine with simple passive safety.

      On top of all that, they have better thermodynamic efficiency since they operate at higher temperatures.

      Wikipedia has a good article on the IMSR design:

      The most famous MSR is the thorium-breeding LFTR, which *is* relatively complicated since it does chemical processing of radioactive fluids. But that’s not what we’re talking about here.

      • Of the various comments, this was the most well-informed.

        The most important feature, the crucial “game changer” is the safety issue. The current industry standard PWR is a potentially massive “dirty bomb” requiring multiple redundant safety systems. Yet even these have proven insufficient — Chernobyl, Three-mile Island, Fukushima — to protect against a combination of “dissembling nature” and creative “operator error”. In contrast, TMSRs are “walkaway safe”. Can’t blow up, can’t melt down.

        Thorium is the nuclear that nuclear should have been from the start. It will go into production first in Indonesia, which wants power for its modernizing society, and which isn’t burdened by politically obstructive environmental hysteria. Thorium will start there, prove itself, and then, being cheaper than coal, will go into mass production for deployment throughout Asia. Then the nuclear-related PTSD in the West will fade, and Thorium will take off there as well.

        • Uhh Jeff, you are feeding the “politically obstructive environmental hysteria” by plugging your pet project while slamming well proven LWR designs. Nobody was hurt at TMI or Fukushima. Paper reactors are always “walkaway safe”, you can walk away from your desk and the paper will still be there tomorrow, and the next day and the next year. If it is such a great design, then why did you have to go sell it to the banana republic with exactly zero experience in nuclear design?

          • None of them have a future as they predict. What should, and will likely happen, is that the MSR lobby will get a green light to build a research facility so that they can continue the work done at Oak Ridge. That will give these Lars Jorgensens and Leslie Dewans jobs so they can actually work out the problems instead of trying to push the cart with the horse.

  8. First it showed two copies, then they were gone. See what happens here!
    “The projected unit costs of LSP electricity, averaged over the 1,500 TWe-y, are . . . 0.0005 $/kWe-h (7.), to 0.0003 $/kWe-h (8.).”
    “IMSR® plants can dispatch power at under USD $50 per MWh (levelized cost)” which is 0.05 $/kWe-h
    “An IMSR® power plant generates 400 MWth of thermal energy (190 MWe)” so would need 100 to 1,000 plants for the 20 to 200 tWe planned for LSP.

    • The Criswell paper you link to quotes Alvin Weinberg’s estimate of the power required for a prosperous world economy, but claims that cannot be sustainably produced by nuclear power. ( Alvin Weinberg patented the light water reactor, and developed the first working molten salt reactors.)
      ‘ A 75 TWt fleet of light water reactors would ingest ~4,200,000 tons/year of natural uranium and thus reduce fuel mass flow through the biosphere by a factor of 84,000 compared to coal. However, proven continental reserves of uranium would last less than 4 years. Uranium ( 238U 99.28% & 235U 0.72%) extracted from seawater would last ~1,000y. Uranium extracted with 100% efficiency would require processing 1.3•1015 tons/y of seawater or 35 times the flow rate of all the rivers on Earth (11). ‘
      The Kuro Shio ocean current flowing past Japan has a flow rate of fifty million tons per second, and a uranium content of 3.3 parts per billion. There are ~thirty million seconds in a year, so if all the uranium was extracted, there would be almost five million tons a year, from one hundred kilometre wide current – more than the world consumption cited. However, if our descendants are still using light water reactors in a thousand years , and so wasting 99 percent of the energy content of the uranium, and sixty-five percent of the heat produced, they deserve energy poverty.
      The IMSR is designed to avoid, where possible, any new technology development, by simplifying everything, swapping out parts before they can develop problems, and using techniques pioneered by Weinberg’s team in the seventies. What is the technology readiness level for all the different systems that would be needed for LSP ? For example, mining on earth takes advantage of ores concentrated by active tectonics and selective solution ( which is why I think ocean extraction of uranium will never be necessary ). None of these apply on the moon, and nor does it benefit from generations of surveying knowledge. Construction metals and glass would be no problem, but what about all the rarer metals you’d need ?
      The only hands-on experience we have on the Moon included some problems with dust. When the lunar buggy’s mudguard broke, the dust sprayed up from the wheel threatened to coat the battery radiators . Can you be sure that maintenance operations won’t gradually coat your solar panels ? No smelting operation has ever been done in low g vacuum, so gremlins there are inevitable. What systems would you need to prevent malicious interference with the power beams, for blackmail or political ends ? Consider that something like 9-11 could theoretically have happened any time during the last fifty years. You’re proposing something with longer, stronger energy flows than have ever been used – how many failure modes will it have ? A ship, or a city, with a freshly fueled nuke, has a guaranteed power source at hand for the next year. One investing in LSP needs the whole enormous thing to be functioning before they get a watt. If anything fails, it’s thousands of kms away, at the wrong end of a gravity well.

      • I have no objections to the possibility of Earth derived nuclear fuel being sufficient, only the costs, which compared to LSP are not only far greater at scale but also include the lost opportunity of opening Space, with funding, a Good Thing(TM), and the bigger reason O’Neill and I support Space Solar Power.
        Mining- Rare elements will be in asteroids and their impact craters. The bits from layers of gravity separated materials that are from bodies blasted apart give us things like Iron meteorites. We will soon know more, but the amounts will be truly astronomical. Surely you are in favor of doing the R&D for Space! BTW, Criswell was studying the dust for NASA when he noticed the intense insolation and thought up LSP, so he is aware of it.
        Also, LSP starts delivering power from the start, unlike the Shimizu plan which requires circumlunar cable before any delivery. It has thousands of beams that spread out from numerous radars on the Moon, so the flows at Earth are at most 20% sunlight. I won’t comment on 9-11 LSP v nukes, being polite!

    “The projected unit costs of LSP electricity, averaged over the 1,500 TWe-y, are . . . 0.0005 $/kWe-h (7.), to 0.0003 $/kWe-h (8.).”
    “IMSR® plants can dispatch power at under USD $50 per MWh (levelized cost)” or .05 $/kWh,
    “An IMSR® power plant generates 400 MWth of thermal energy (190 MWe)” or 100 to 1,000 plants to equal the 20 to 200 tWe of LSP, which is also dispatchable.

    “The projected unit costs of LSP electricity, averaged over the 1,500 TWe-y, are . . . 0.0005 $/kWe-h (7.), to 0.0003 $/kWe-h (8.).”
    “IMSR® plants can dispatch power at under USD $50 per MWh (levelized cost)” or .05 $/kWh,
    “An IMSR® power plant generates 400 MWth of thermal energy (190 MWe)” or 100 to 1,000 plants to equal the 20 to 200 tWe of LSP, which is also dispatchable.

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