Interesting New Nuke Reactor – Molten Chloride Fast Reactor

The rector abbreviation is MCSFR Molten Chloride Salt Fast Reactor and the company is Elisium.

It can use “Spent” nuclear fuel from light water and other reactors (i.e. it uses the 40 years worth of “nuclear waste” as fuel) and does so in a very simple process that is NOT complicated like regular reprocessing. Basically, chop the fuel, react it with chlorine, separate out the non-reacted metal bits, and go.

A 1 page pdf seminar handout:

The company site tech page:

It is very efficient:

Using a liquid fuel and a fast neutron spectrum allows for the efficient utilization of almost all the nuclear fuel material leading to lower total fuel costs over the lifetime of the reactor. Elysium’s reactor burns over 95% of fuel, as opposed to 1-4% for thermal water reactors. Even after a reactor is decommissioned, the fuel can be reused in follow-on reactors.

It automatically load follows, and it is passively safe:

The Elysium reactor has clear negative coolant temperature and void coefficients of reactivity; reactor power will decrease as temperature increases or if bubbles form in the molten salt. This is fundamentally important to enable load following without operator intervention, to allow inherent passive reactor operations and safety response, and to simplify reactor control systems, thus increasing safety and reducing cost by eliminating human operator actions.

People pay you to take their “waste” as your fuel. Uses just about any nuclear fuel material:

Elysium’s design is a fast-spectrum reactor meaning the majority of fissions are caused by high-energy (fast) neutrons. This enables conversion of fertile isotopes into energy-producing fuel, efficiently using nuclear fuel, and closing the fuel cycle. In addition, this can enable the reactor to be fueled with spent nuclear fuel from water reactors. The Elysium MCSFR closes both the water reactor and its own fuel cycle.

I find it interesting that there is NO moderator used… That whole “fast neutron” thing…

Name: Molten Chloride Salt Fast Reactor

Reactor Type: Molten Salt Reactor

Neutron Spectrum: Fast

Fuel Form: Liquid

Salt Form: Chloride based Fuel Salt

Moderator: None

Thermal Capacity: 110 – 2700 MWth (Flexible)

Electrical Capacity: 50 – 1200 MWe (Flexible)

Fuel Cycle: Closed

Designers: Elysium Industries Limited / Elysium Industries USA

A Ra-Ra General Audience article:

Elysium Molten Chloride Salt Fast Reactor will use existing technology for rapid approval
Brian Wang | July 20, 2018

The Elysium Molten Chloride Salt Fast Reactor (MCSFR) is state-of-the-art in its design. Elysium’s technology is unique as it can provide base-load and clean power while addressing the current issues in the nuclear power industry. Based on demonstrated technology in the 1960s, Elysium has adapted and improved the molten salt reactor design for commercial deployment. In addition, the Elysium reactor has the ability to consume spent nuclear fuel and weapons waste transforming it into useful energy.

The Elysium MCSFR will be built utilizing existing code-qualified materials and relies on natural processes. Elysium is simplifying engineering systems saving cost with natural techniques for passive operation and safety.

Everything that Elysium is choosing is to only use what is qualified and working at this time.

The design is barely critical at all times. The flow rate of material controls the power output.

One reactor vessel for all sizes of power plants and power levels.

etc. etc.

The designer talking about it in 24 technical minutes:

This one looks like a “keeper” to me.

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About E.M.Smith

A technical managerial sort interested in things from Stonehenge to computer science. My present "hot buttons' are the mythology of Climate Change and ancient metrology; but things change...
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34 Responses to Interesting New Nuke Reactor – Molten Chloride Fast Reactor

  1. p.g.sharrow says:

    Elysium Molten Chloride Salt Fast Reactor “Based on demonstrated technology in the 1960s, Elysium has adapted and improved the molten salt reactor design for commercial deployment.”

    I thought it looked like old technology that I once studied. This was tested and worked well except for one small problem The hot molten salts were a nightmare to contain for long periods. Corrosion/Erosion ate up the internals very quickly. IIRC they shut down the tests after 6 months because they became unsafe. Also clearing the spent material from the salts was a big problem as well.
    Another system that sounds great on paper but had really big problems during execution. That self destruction caused by the salts was the real deal killer that they couldn’t solve at the time…pg

  2. Simon Derricutt says:

    pg – IIRC the Oak Ridge molten salt reactor ran for around 4 years. Yep, problems with those extremely corrosive salts, but not too badly at the time and I expect that there are now better materials available. It was decommissioned because the research funding ended, not because it wore out. I wouldn’t write this off as infeasible because of the corrosion problems. Like a lot of things, it probably just needs a big-enough investment in research to arrive at a design that is cheap enough to make, and at the time there was a requirement to produce boom stuff that a molten salt reactor doesn’t produce. The cost of the electricity wasn’t as important at the time since it was a by-product of producing the required isotopes.

    Since the fuel for these MSRs comes at a negative cost (since otherwise the waste would be stored and that is expensive) then it’s worth making this technology work.

  3. A C Osborn says:

    Simon, Wiki has a very nice write up on the reactor and it was actually in operation for 5 years.

    If they could do it then we should be able to do it even better now.

  4. jim2 says:

    MSRs in general can “burn” spent fuel from conventional reactors. And of the common halogens, the chloride ion is the most corrosive which is why fluoride is the typical choice for MSRs. The reactor characteristics outlined in the post are for MSRs in general, which is why they are so attractive.

    While I was looking for a relevant web site, I was disturbed to find several negative articles on MSRs. Looks like the loony-left cancer has struck in this area also.

    Here is a company with a commercial offering. I need to dig here a bit more, but here it is:

  5. jim2 says:

    Seaborg is the largest reactor design start-up in Europe. They have a design for a molten salt reactor that is ten times smaller than the Terrestrial Energy IMSR. It would 20 to 30 times smaller than an existing pressure water nuclear reactor for submarines.

    Seaborg CUBE reactor can use spent nuclear fuel (SNF) by adding thorium as a catalyst. The CUBE as a waste burner. Current conventional reactors use about 4% of the uranium fuel rods. This is because they use Uranium 235 and cannot use the Uranium 238.

  6. E.M.Smith says:

    That Seaborg Cube is very interesting. 1/2 length container sized? Just dandy for small remote communities.

  7. jim2 says:

    I’ve thought for a while that MSRs or SMRs would be a good pick for remote villages and remote large mining operations. Toshiba wanted to put in a SMR free for Galena, Alaska a decade ago but was sidelined by regulations, I think it was. Galena has to have diesel shipped to the town of about 500.

    This is an area where Trump could make a(nother) real difference.

    MSRs might need more support due to the removal of waste that isn’t required for SMRs, so maybe SMRs would be a better choice for remote operations.

    Here is a military application …

  8. E.M.Smith says:

    The thing I find interesting is that it is all about neutron economy. You can make a reactor about 1 cubic foot if desired. Just conserve enough neutrons and you are good to go. Problem is that most of them Go Boom! at that size ;-)

    Or you can make things that cover a house sized area (or an acre) and just boil water, if everything is Just Right.

    And all points in between.

    My favorite tech, really, are the submarine reactors. A blob of highly enriched Uranium and neutron reflective baffles. Turn them edge on, it cools down and not much happens. Turn them flat side on, neutrons are reflected and conserved and it’s off to the races….

    Neutron speed, conservation, moderation of speed, and number needed vs produced per fission for a given fuel pretty much drive the whole show. The rest is supporting cast.

    In the smallness limit you have the thermogenic generators where “natural decay” provides the heat to thermocouples. No neutron management needed as it is just natural decay heat. Can be most any size, really. Adding a neutron shield makes them hotter (and protects you) but that’s about it.

    I’ve sporadically thought it would be fun to make a very small nuclear plant (like the kid who used the smoke detector isotopes ;-) but always thought better of it… Now I’m not sure where my Geiger counter has gone in the garage and the idea has lost some of the luster… Cold Fusion looks more interesting… But as we’re some several years past when Rossi said it was production ready, and still nothing, I’m pretty much jaded on it, too. Frankly, 2 fingers of Scotch is more interesting now ;-) (I refilled the inventory ;-)

  9. p.g.sharrow says:

    Neutron conservation is very important! With enough flavored ethanol anything is possible. 8-) pg

  10. E.M.Smith says:


    Hmmmm Water makes a great neutron reflector, you just need a lot of it (thus the Pool type open research reactors where the thing sits in a water bath). C and CO2 make good moderators… Ethanol is the same set of atoms: C, O, H.

    So logically you could make a decent Pool Type Reactor using a pool of ethanol (of any desired proof)… so, yeah, I guess anything us possible. Not sure about the flavoring, though. Ought to depend on the specific atoms in it…

    BTW, IIRC, polyethylene or similar plastic has been used as a moderator in some lab work, for similar reasons.

    Might be hard keeping the staff alert with the vapors coming off the pool, though ;-)

  11. E.M.Smith says:


    A very interesting article, but even while pointing at the positive indications, also shows that after 30 years the best he could claim was a probable 50 W device that required calorimetry to be sure.

    IMHO, after 30 years, it ought to have kW scale devices on display or for sale. They aren’t, so… It is either an error case, or so hard to get right that while a theoretical works, is an Engineering nightmare; so not practical (in the classic sense of reducible to practice).

    Yes, by all means continue to investigate! But I’m not going to be excited about it anymore until I can buy one from Honda and power my car or house with it… Basically my threshold for hope and belief have been shifted way high by too much hype and not enough deliverables.

    Maybe there’s something in his links to evidence, but had he some killer evidence, it ought to have been mainline, not sidebar or link out…

    FWIW: I am quite certain LENR reactions happen. I just doubt it is workable enough to get out of the lab curiosity category.

  12. Simon Derricutt says:

    EM – maybe the most hopeful LENR experiments at the moment are those of Tadahiko Mizuno. . He’s been beavering away at various methods for a long time, on a low budget but having acquired some useful kit over the years that would be expensive to replace at today’s prices.

    This doesn’t mean that it’s easy to replicate, and it’s even difficult for him to get a replication. However, he did use his experimental reactor number 21 as a room heater and estimated around 3kW from it (the calorimeter didn’t measure that high, so measured output up to a few hundred watts).. He has published a “recipe” of how to replicate, and the people currently trying “replications” aren’t exactly following it.

    I’d trust Mizuno’s measurements and observations. However, he isn’t certain which particular steps in his methods are critical and which are optional, or how it could be improved. This is unlikely to be known unless somebody makes it work reliably. It could be because of trace elements in the Nickel mesh he uses or in the Palladium he rubs on it, the heat-treatment state of those metals, some trace from the Silicon Carbide paper he uses to prepare the mesh, something in the water he uses for washing things (the water in Sapporo has a fairly high Calcium content), or other things that people haven’t thought about. It does seem that the wrong impurity stops it working (Sodium or Potassium from fingerprints is known to cause failures in Pons-Fleischmann replications). Outgassing during vacuuming-down needs care, and setup might take a couple of weeks of high vacuum before enough gases have been removed. Bottom line here is that it’s not easy to do, but it is at least possible with some luck along the way and running clean enough.

  13. p.g.sharrow says:

    I find it interesting that Main Stream Fusion has not met unity yet after 60 years and billions of dollars and they are a “credible” effort while LENR has some kind of positive? output? maybe and it is considered “Quack” science. Those that labor in the LENR field work with little in the way of funding or assistance while developing something that will likely result in government efforts to prevent them from any use of the technology that they are trying to develop.
    At first I thought Rossi had something going on but after he joined with that Energy equipment supplier I could see that he and his technology was trapped and could not advance.
    I still believe that LENR is the correct path but a few more steps are needed to bring it under control. It must be actively operated and managed, just setting up a cell and hopeing it will work won’t. It will need a pulsed energy field to push – pull the mater/energy density across the Neutron Threshold, That is where the energy/mass conversion is….pg

  14. Larry Ledwick says:

    It appears there is a competitor to the molten salt designs that also is based on fast reactor principles.

    It was/is backed by Bill Gates

  15. p.g.sharrow says:

    Bill Gates is not to be trusted, He has a long history of shafting his partners to gain advantage and power. He has only one loyalty and that is to Bill Gates….pg

  16. A C Osborn says:

    There is another company that is way out there with it’s design for Heat Generation.
    Claiming that it is powered by “Dark Energy”.

    They do appear to have “something” according to their test results, if the can be believed.

  17. jim2 says:

    A C O – This is a re-branding of Blacklight Power with Randall Mills still trying to foist this nonsense off on anyone who will listen. This has been going on almost as long as “cold fusion” Since this guy claims to have a for-sure theory, something generally lacking in the “cold fusion” field, there is no excuse whatsoever for him NOT to have a water heater based on it. Decades ago there was a Yahoo group that discussed this ad nauseum. The group included some PhD physicists and chemists.

  18. Bruce Ryan says:

    I’m kind of living with the hope out to fix things now. It may not be a good strategy.

  19. E.M.Smith says:


    One of the things I’ve speculated might be needed is a small amount of microwave energy to vibrate things (moving the hammer and anvil of inter-atom spaces). We’ve got enough of it bouncing around that some labs would have ‘enough’ and others not. Now near the airport? Where’s the cops speed trap? Is your cell phone near the apparatus ( especially back when they were 4 Watt lugables not the .4 Watt of now.) and more.

    I’m pretty sure the “gimic” is to get small hydrogen into the space of a metal, and delocalize the electrons, then squish the space just enough to push the proton inside the electron shell of the metal. The rest would be nuclear forces… So you need the right sized space, then shrink it or vibrate the atoms so the space gets smashed some.


    Oh, and I second the “Don’t Trust Gates”. He’s a sleaze.

    @Bruce Ryan:

    Bill Gates is in bed with the people who believe in “Doing well by doing good” – i.e. find something good the world needs and line your pockets off of claiming to want to fix it… He might accidentally do some good, but watch the pockets…

  20. p.g.sharrow says:

    @EM; I would agree, a very short wave carrier tuned for effect and then a secondary wave for power control. You have to push the power up and pull it down because once started it (the reaction) wants to run away,
    If B.Gates really wants to finance a solution he needs to finance this group. 8-) …pg

  21. Larry Ledwick says:

    Then this comes along and tosses out all the previous theories ( at least adds to them).

    What interesting new possibilities will come out of this research if it is validated?

  22. rocketplumber says:

    Another molten chloride salt proposal is from
    They use just the bare minimum of chloride salt, important because you need to use Cl37 to avoid absorbing neutrons, and they put the molten fuel salt inside stainless tubes with a Zr anodic plating to prevent corrosion. The coolant bath is a mix of fluoride salts with no fuel content, then two stages of other salts to carry the heat away and optionally store GW-hours worth of heat externally to allow load following without perturbing the reactor.

    The fuel rods handle very much like conventional solid rods, making the IAEA much easier to placate and allow on-line refueling by robotic rod shifting. Used rods remain in the main pool for a year or so, and all that decay heat is used to generate power, pretty clever. Their main plan is for a waste burner reactor, giving them a few decades to refine the uranium and thorium designs while they work through the backlog of old PWR fuel.

  23. E.M.Smith says:

    Interesting idea… Sort of a halfway house reactor to get the regulators used to the whole thing and comfortable with salt…

  24. gallopingcamel says:

    Suddenly designing SMRs (Small Nuclear Reactors has) become fun again as Freeman Dyson suggested. Without trying too hard I have found 40 different designs and probably missed as many more. Most of the projects are at an early stage and some are “Vapor Ware” with little more than slick videos. Even so there are lots of clever people having fun.

    The good news is that three SMRs are under construction, one is an Argentinian project and the other two are Russian based on the engines used in nuclear ice braekers.

    Three more designs are seeking funding but IMHO nothing will happen in the USA until the licensing process is changed. It is doubtful if the kind of changes that are needed can be “sold” to the current regulating bodies so I recommend setting up a new licencing authority for intrinsically safe reactors that operate at low pressures.

    By intrinsically safe I mean that if power is lost the reactor shuts down without human intervention. For example the Kirk Sorensen’s LFTR has freeze plugs that ensure the reactor drains down under the force of gravity alone.

    The Elysium MCSFR featured above needs a pump to be active to fill the reactor vessel. If the pump fails the reaction mass drains away into a storage tank.

    I am greatly encouraged by the folks at Moltex who claim (plausibly IMHO) that their reactor will be less than 10% of the size of an AP-1000 and just a fraction of the cost. Molten Salt Reactors have the potential to be cheaper to construct than fossil fuel plants given how tiny they can be and the fact that the amount of fuel to be handled is at least 1,000,000 times less than a comparable fossil fuel plant.

  25. Larry Ledwick says:

    As I recall the Japanese (Fuji industries???) were pushing small modular reactor designs a few years ago, but I have not heard anything about them for some time.

    Looks like they were looking at HTG (high temperature gas cooled designs which can also be intrinsically safe) Their HTGR design details are very similar to the Ft. St. Vrain HTGR here in Colorado that Public Service company built. It has some minor design issues most of which they eventually resolved, but the licensing an approval process after each shutdown as they sorted it out became prohibitive and for economic reasons they retired the reactor and changed power generation to natural gas steam to drive the generators to recover costs after 10 years of operation as the first commercial HTGR in the US.

    Japanese modular reactor concepts

    Click to access japans_smr_designs_kazuaki_matsui.pdf

  26. p.g.sharrow says:

    There is certainly no doubt that in the U.S. and associated countries the regulatory regime and requirements have been created to eliminate all civilian Atomic generation plants. I remember encountering a legal association that bragged that they would bankrupt anyone that attempted to build a nuclear power plant.with constant legal challenges and disruptions….pg

  27. E.M.Smith says:

    Lawfare. It ought to be illegal.


  28. jim2 says:

    Yep, the NRC couldn’t care less if nuclear reactors are used or not … from their web site:

    The NRC’s mission is to license and regulate the Nation’s civilian use of radioactive materials to provide reasonable assurance of adequate protection of public health and safety and to promote the common defense and security and to protect the environment.

  29. jim2 says:

    But then there is this …

    The Office of Nuclear Energy (NE) mission is to advance nuclear power to meet the nation’s energy, environmental, and national security needs.

    Under the guidance of three research objectives, NE resolves barriers to technical, cost, safety, security, and proliferation resistance through early-stage research, development, and demonstration to:

    Enhance the long-term viability and competitiveness of the existing U.S. reactor fleet.
    Develop an advanced reactor pipeline.
    Implement and maintain national strategic fuel cycle and supply chain infrastructure.

  30. Larry Ledwick says:

    Don’t tell Germany they are busy creating a nuclear waste and power availablity problem that is avoidable. Using one of the fast neutron reactor designs and allowing these stations to run till end of life, they could have reliable base load power, and burn up their nuclear waste.

    I find it interesting that in the WWII period Germany was one of the scientific leaders of the world (yes their politics was screwed up, but they did good science). Now they seem to be falling all over themselves to make bad scientific decisions regarding energy and bad decisions about politics.

  31. E.M.Smith says:

    Yeah, another bogus non-problem from which Billions of tax money will be extracted.

    It isn’t waste, it is 95% pure fuel.

    They ought to just sell it to India or let France reprocess it. At least if they are stupid enough to not use it themselves.

  32. p.g.sharrow says:

    @Larry; I don’t think it is a matter of poor science, their science seems to be as good as anyone’s. The Germans seem to follow poor politics. The Liberal Progressive meme always seems to result in bad political decisions. As Reagan observed. Liberals know all the wrong answers to any problem. It is the Education system that is plagued with socialists that train the politicians and bureaucrats in social science, political science and socialist economics that to blame for this drive towards all the wrong decisions. And their argument to correct their failures is to double down on those bad decisions. “We must try harder!” because we can’t be wrong.

    FDR’s Secretary of Treasury is said to have remarked in their 7th year, “Everything we have done seems to have made the Depression worse” That was a Fact that is ignored in all modern history books. FDR’s “New Deal” socialism is credited in all Education books as the Savior of the American Economy! The fact was that the stock market crash recession was nearly over with when the FDR Administration took power and forced a Banking holiday that destroyed the small banks to save the big ones that were hurt in the crash and stopped all business in flyover country outside of the big cities. They also put much of the economy under Federal control. Much the same thing was done after the Banking crash of 2008 by the Obama Administration with the same results. Trump followed much the same program as the Eisenhower Administration by Reducing much of the Federal regulatory strait jacket that was Preventing Recovery from taking place.

    I wonder is the new history books will reflect these truths or will they double down on the same wrong answers? …pg

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