C$10 Million to Develop First Molten Salt Molten Reactor

Moltex was founded in 2014 by Dr. Ian Scott, and was privately funded until 2018. Moltex’s mission is to enable low-cost clean energy as a practical economic solution.

On 2018-07-13, New Brunswick Power and NB Government agreed to build, own and operate a SSR-W300, with New Brunswick and Moltex each funding CAD $5,000,000 towards development. Moltex Energy’s North American headquarters is in Saint John, NB.

Moltex is currently part way through Phase 1 of 2 of Canadian Vendor Design Review.

They are one of eight reactor designs competing for about 56 million pounds in funding in the UK.

In 2016, Moltex talked to Nuclear Energy Insider and said their overnight capital cost would be under $2/W based on an independent cost estimate by a leading UK engineering firm. Further reductions to this overnight cost are expected for modularised construction. For comparison, the capital cost of a modern pulverized coal power station in the U.S. is $3.25/W and the cost of Hinkley Point C is $7.46/W.

$2 per watt capital costs are about the level of cost that China has for nuclear plant construction.

The overnight capital cost of the SSR is estimated at $1.95/W based on a 1 GW plant, according to Moltex Energy. In comparison, U.S. overnight capital cost of coal-fired generation is estimated at $3.25/W, gas-fired generation at around $1/W and large-scale nuclear at $5.5/W, the Energy Information Administration (EIA) said in a 2013 study.

Lower-cost nuclear reactors would be able to compete for 30% of the estimated world energy market in 2040.

The Levelised Cost of Energy (LCOE) of the SSR is estimated at $44.64/MWh for a 1 GW plant and this is based on highly-conservative estimates for Operations and Maintenance (O&M) costs, O’Sullivan said.

This LCOE is far below the EIA’s cost projections for new coal and gas-fired units in 2020, at $95/MWh and $75/MWh, respectively.

Canada’s Terrestrial Energy has said the overnight capital cost of its molten salt reactor design also competes favorably against fossil fuel plants and has projected a LCOE of $40-$50/MWh for a 300MWe plant.

This low capital cost results in a Levelised Cost of Electricity (LCOE) of just $44/MWhr with substantial potential to be yet lower

Adam Owens of https://moltexenergy.com/ outlines Moltex Energy’s 3 reactor designs:
SSR-U and

Each one targets a different world market, with the primary distinction being SSR-W is fueled by Plutonium from spent reactor fuel.

Timecode index…
00:48 Moltex technology portfolio is described
02:07 Rapid deployment – avoid hardest regulatory hurdles
02:50 Gigawatt scale
03:29 first-of-kind MSR technology investable by private industry
04:40 3 variants of fuel cycle: SSR-W, SSR-U, SSR-Th
05:25 Grid reserve – act as a peaking plant like a CCGT
06:37 WATSS – WAste To Stable Salt
07:10 Moltex company background – founded in 2014
08:05 Activities in UK – AMR Feasibility Study
09:07 Activities in Canada – Vendor Design Review
10:13 MOU with New Brunswick Power (Canada) Pilot SSR
11:42 SSR-W (Stable Salt Reactor Waste Burner)
14:20 SSR-U (Stable Salt Reactor 5% low-enriched Uranium)
15:51 SSR-Th (Stable Salt Reactor Thorium breeder)
16:54 Deployment Roadmap – requires a mix of all 3 reactors

– Fast-spectrum Wasteburner fueled by Pu from spent fuel.
– Molten chloride salt fuel, NaCl-AnCl3 fueled.
– Primary coolant is NaF-KF-ZrF4.
– WATSS (Waste to Stable Salt) recovers An/Ln from spent oxide fuel liabilities.
– Core modules contain reactor core components inc pumps and heat exchangers.
– SSR-W1000 is an identical design with more modules in a longer tank.
– 525-630C.

– Low Enriched Uranium Burner (~5%).
– Molten UFx salt fuel.
– Adopts current water reactor fuel cycle infrastructure.
– Design heavily-related to SSR-W.
– Larger core volume than SSR-W.
– 600-700C+.

– Thorium Breeder.
– Molten UFx salt fuel.
– Thorium-based coolant supplants the zirconium-based coolant.
– Fertile primary coolant NaF-ThF4.
– Bismuth extraction column extracts Pa/U into a U238 diluent.
– ~5% U233 alloy is processed back into stable salt fuel.
– 650-750C+.

24 thoughts on “C$10 Million to Develop First Molten Salt Molten Reactor”

  1. Alloys not usable for multiple decades, this is why Terrestrial is only running a core for 7 years. Bypasses alloy issues, graphite issues.

  2. By way of comparison NuScale is spending $10 million every month working towards building their reactor and they have a customer.

    The first $10 million doesn’t buy much.

  3. Thanks, very interesting! Continues to amaze me how this industry and other large-scale (eg petrochem, even down to drillbits) is basically a series of one-off builds that somehow can still make money (in the long run). But it appears that Gen4 has the potential for standardization, eventually.

  4. I’m no chemist, but Terrestrial and Thorcon claim they can get away without using Lithium, though it would improve their neutron economy if Li7 became available later. I think Thorcon want to use NaF, BeF2, Terrestrial are cagey about their salt, and Moltex use NaCl for the fuel salt, ZrF4/NaF/KF for the coolant. None are net breeders, but they don’t have to be – until nuclear makes a high proportion of world energy use, there’s plenty of fissile. Once we get to that point, and there’s an incentive to produce Li7, it should be a lot easier than U235 to enrich – the mass difference to Li 6 is 13 times bigger than 238/235. (Moltex’s fuel salt is at a pretty high temperature, but they claim putting it in light-water reactor style fuel tubes means the tubes will equalise to the temperature of the fluoride salt outside them, not the chloride salt inside.)

  5. “The second reason to choose chlorides is because uranium trichloride is substantially more stable to disproportionation than is uranium trifluoride. This allows chloride salts to be rendered so strongly reducing, through contact with zirconium metal, that corrosion of metals is virtually completely thermodynamically prevented. That cannot be achieved with fluoride salts without causing uranium metal deposition. Fluoride salt use therefore drives reactor designers to require special high nickel alloys which have no recent nuclear experience of use. This represents a substantial technical barrier to rapid deployment.

    Moltex has a granted international patent on the use of chemistry control with molten salts in this manner.”

  6. https://www.moltexenergy.com/learnmore/An_Introduction_Moltex_Energy_Technology_Portfolio.pdf

    “8.2.Chloride fuel salt to allow highly reducing redox state and hence standard steel use.

    The choice of chloride salts for the fuel was not driven by neutronic concerns. Chloride salts do permit a somewhat harder neutron spectrum and hence better neutron economy than fluoride salts but that was not seen as a compelling argument for a reactor where the overarching strategy was to enable rapid deployment.

    The first reason to choose chloride salts was that such salts allow high concentrations of actinides to be used at temperatures low enough to allow use of standard steels. With fluoride salts, the achievement of sufficiently low temperatures usually requires use of lithium or beryllium salts. Both of those elements, even if isotopically enriched, generate large amounts of tritium in reactors – orders of magnitude more than the unavoidable tritium from rare ternary fission events. Since tritium readily penetrates metals in molten salts the use of tritium generating base salts would require development of an effective tritium scavenging system. That technological challenge would inevitably delay reactor deployment.”

  7. Read the comments. It should be known that water is corrosive. And that neutrons destroy the structural strength of material that is suppose to contain the pressure of a PWR. There will always be issues and for some issues we will find solution. The PWR has one big issue and that is if you lose coolant you lose the reactor.

    As for MSR the containment structure should be a lot cheaper than that of a PWR. Worse come worse just exchange one containment structure for another when it gets too corroded.

  8. Hastelloy N was found inadequate for fluoride salts already. Why consider it for much harsher chloride salts?


    It isn’t like molten salts haven’t been investigated – they have for non-nuclear thermal storage. Only nitrate based ones have passed muster, and those aren’t compatible with neutron activation. They can only be used in MSRs in secondary heat exchange loops. If fluoride and chloride salts are too harsh for thermal storage, they’re even worse when you add neutron bombardment as a problem.


  9. Why wouldn’t they also test Hastelloy-N which was used for years in an actual MSR and showed very little corrosion resistance?

  10. What do you feel is the best solution for Li7? Crown vapor or AVLIS? Or other? And yes, beryllium on the morning granola is not a good idea. I guess one could always use only LiF, but then higher temperatures? I dunno, i’m still in the learning phase…

  11. Lithium they’d have to wait for somebody to develop enrichment facilities – it has to be 99.995% Li7, or the Li6 eats all the neutrons. They might get away with a bit less in a fast reactor, though. And beryllium is quite poisonous.

  12. excellent.

    I’ve looked into this as well, from an investor POV. The corrosion issue is real. There are some materials out there that can handle this. The big “if” is whether with additive manufacturing and other processing the cost point can “make the numbers work”. I’ve seen some prototype materials get close enough. But – then, why not just use this tech to make existing plants so much more efficient (given the capital depreciation already “built in”)? I rather be in the materials business than the MSR business!

  13. see above. Some degree of over-enthusiasm here, but not too way off. Moltex is not the MOST efficient design I’ve seen but it’s good to see it coming along. I would prefer LFTR with lithium and beryllium. Much simpler, though the component corrosion issue needs to be solved, economically. That goes for all the designs.

  14. You may have misread?
    $10m for initial assessment, ie powerpointing and project planning.
    They reckon $44.64 LCOE overnight for a 30 year plant lifetime for a 1GW plant. That comes to roughly $800m to build and about $40m a year for fixed and variable costs.

    Ie pretty much in line with advanced combined cycle gas. BUT, methinks given this is a first-time plant their fudge factor is way underestimated. I think they are closer to $60 LCOE. Everything will depend on the efficiency rate. Still, though, not so bad. Basically, goes to show even initial *new* power tech can be quite competitive. Once you’ve built a dozen or so of these, then the build and op costs will drop. Unless, of course, you get buried under mountain of regs – and that is REAL paperwork.

  15. The Moltex guys
    are wearing ties –
    should Westinghouse
    take notice ?
    I’ll see your blank verse and raise you doggerel.

  16. Have we reached peak paper reactor hype yet? At least peak molten salt reactor? I think I could list 20 different molten salt concepts/designs if I thought long enough.

    I say this having worked on molten salt corrosion and nuclear chemistry projects at university and national labs, and have met like 2 or 3 people that seemed like they had any idea of the issues. Lots of people apparently do rough thermal or cfd calcs, sketch out a concept, and think they have a real winner.

    Is the government so desperate to try to maintain nuclear interest at the university level they are funding outlandish research, with practically no realistic path to commercialization? LWRs work now. Just need to make them cheaper or operate more efficiently. Make the NRC less burdensome, and cut out the paperwork, certifications, and redundancies.

  17. It’s a good start. Recognize that my reality check is rooted in jealousy. I know what it feels like to be part of a team at this stage. It feels great. It feels like 1935 Germany and officials give you, a new grad, specifications for the aircraft they want… except nobody is asking in this case. Here they invented the cause. If the Govn’t asked, there’d be a team; people would shave their beards in the morning, promise nothing outlandish, and quote every factor scaled by 0.8.

  18. $10M to develop a reactor? I’d be surprised if that money covers the cost of the paperwork.
    Not the cost of writing the paperwork, just the material cost of the paper, ink and printing.


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