I have no idea if molten salt reactors are as awesome as this website represents them to be, but I thought the following point was interesting:
"light water reactors can use only about 4% of their available energy."
They're comparing with 1960s reactors designs, so maybe more modern water reactors are more efficient. But, it's still amazing to me that there's that much more energy that we could potentially harness from the fuel.
It's because light water reactors use thermal (i.e. slowed down) neutrons, which can only fission U235, and that's 0.7% of natural uranium. We enrich the fuel to at least 2% U235 and that's mainly what the reactor can use.
The reactor also gets about a third of its energy by fissioning plutonium, which is formed when U238 absorbs a neutron.
Without reprocessing, a light water reactor can't even fission all the U235, because some of the waste products of fission reactions are strong neutron absorbers. (If you're in France you can reprocess the waste to remove the fission products.)
Molten salt reactors remove most of the fission products continuously. Some MSRs, like Terrestrial Energy's, are still thermal reactors using uranium, so they're about as efficient as France.
Some MSR designs use fast neutrons, which are able to fission more plutonium along with other transuranics and U238. Others use thorium fuel, which can be completely fissioned by thermal neutrons. (First thorium absorbs a neutron and becomes U233, then that fissions. Heavier non-fissile isotopes aren't created in the first place.)
Currently the fuel is very inexpensive - a tiny fraction of the total cost of the electricity produced. Most of the cost is the initial capital, and most of the ongoing cost is the (highly specialized) labor. A new reactor design that saves fuel is not really what the industry needs.
Site isn't working now, but their GitHub is here [1]. My understanding on this is that Transatomic started as two young MIT students/grads who did some calcs on a molten salt reactor, found that they could run on high-level nuclear waste in a thermal-neutron spectrum, got really excited, and started a company. They did TED talks and everything [2] and really became this awesome story about advanced nuclear, nuclear startups, private investment in nuclear doing exciting new things, and so on. They were heavily featured in a documentary about advanced nuclear [3] that you can get on Amazon, where we all got a look in their doors.
Then the trouble started. They (smartly!) asked MIT to do a design review and a few questions came up on their key claims. Turns out, there were some calculation or assumption mistakes that showed that it couldn't just run directly on nuclear waste (you traditionally need fast neutrons and/or aggressive reprocessing to do this, even in molten fuel) [4]. They adjusted their copy and moved forward with an adjusted design and new calcs. Eventually they decided to close up shop and open source their design effort as a soft closure.
It's highly regular for advanced nuclear efforts to adjust their design and strategy as they move forward. In fact, I'd go so far to say it happens in 100% of efforts. The only thing Transatomic did that might be a lesson learned is that they got really hyped up early on in their effort, before they shook it down with engineering reviews and whatnot.
As far as I can tell, no one is curating progress or roadmaps in the open source effort. I LOVE the idea of open-source reactor design. It gets around huge institutional barriers clogging up opportunities for collaboration and alignment in the nuclear space. Nuclear is traditionally very secretive, and all these startups promising the world in 2024 without collaboration is basically a doomed effort. The industry must team up, find overlapping tech development efforts and facilities, and work together to build a market. Once they build the market, they can worry about competing in it. Open source can also transcend traditional funding cycles, like when national labs work on a reactor for 2-4 years, make tons of exciting progress, and then drop it. If it's open, universities, international institutions, companies, etc. can all coordinate on it.
Doing open source reactor design would require a lean and highly-dedicated non-profit or foundation or something with a handful of nuclear design pros in it to do the coordination. These projects don't run themselves. It would also need lots of legal resources to navigate export control space. Everything Adm. Rickover said in 1953 about academic vs. practical reactors is incredibly accurate to this day [5], and using open-source philosophy to face these facts brutally may be essential for progress in nuclear.
If anyone has ideas on how to fund that kind of thing, let me know.
Your proposal would be a great fit for the Effective Altruism community. Climate change is an existential risk and if this organization has a 0.1% chance of working out. The utility function for that ROI versus failure would still work out I’m the favor of funding this idea.
Funding will always be contingent, in the minds of most readers, the trustworthiness/robustness of a rough path that goes from a brain trust to a prototype reactor. If we can solve that, we could probably get significant funding lined up by 2024
> and all these startups promising the world in 2024 without collaboration is basically a doomed effort.
Indeed, I always thought that for any company the idea is 5% of the success, everything else is the execution. If a company can use a perfectly working design and just run it (as in PowerPlant as a Service) then that's where the value is, both for them in financial terms and for the society in advancement terms. Commoditize the design of the core reactor and innovate on its different uses and the whole supply chain.
Hard to see how open source nuclear reactors would work. Open source works well for software because getting to the 80% solution is fun, and most people only need the 80% solution. An 80% nuclear reactor isn’t useful to anyone, and even getting to 80 percent is not that fun. Getting to 20% is a blast, but then it is time to do all of the tedious work.
Edit: I should have your Rickover link before posting. It captures my point in more detail, and with more pith.
I helped run a TEDx event (I did event branding and ad designs) where Leslie Dewan gave a talk about this! Unfortunately it looks like the video from her talk at our event isn't up yet, but I will ask the team if they could have it posted.
Its cool that they open sourced their design. I thought it was very likely that they would fail, even more so then most nuclear startups. They made design choices that were questionable and their claim to run directly of nuclear waste seemed very surprising. They also seem to be way to optimistic about the regulatory and business aspects.
For those interested, Terrestrial Energy and Moltex Energy are somewhat more serious attempts to build molten salt reactors, both are quite different form Transatomic.
Terrestrial Energy and Moltex both are in the regulatory process in Canada (the only place a new reactor can realistically be approved) and Terrestrial Energy is the furthest along of any GenIV reactor in terms of commercial regulation in the Western world.
This talk by the main designer of Moltex is a pretty nice summation why they think it would work:
[+] [-] webdevatlurk|6 years ago|reply
"light water reactors can use only about 4% of their available energy."
They're comparing with 1960s reactors designs, so maybe more modern water reactors are more efficient. But, it's still amazing to me that there's that much more energy that we could potentially harness from the fuel.
[+] [-] DennisP|6 years ago|reply
The reactor also gets about a third of its energy by fissioning plutonium, which is formed when U238 absorbs a neutron.
Without reprocessing, a light water reactor can't even fission all the U235, because some of the waste products of fission reactions are strong neutron absorbers. (If you're in France you can reprocess the waste to remove the fission products.)
Molten salt reactors remove most of the fission products continuously. Some MSRs, like Terrestrial Energy's, are still thermal reactors using uranium, so they're about as efficient as France.
Some MSR designs use fast neutrons, which are able to fission more plutonium along with other transuranics and U238. Others use thorium fuel, which can be completely fissioned by thermal neutrons. (First thorium absorbs a neutron and becomes U233, then that fissions. Heavier non-fissile isotopes aren't created in the first place.)
[+] [-] comicjk|6 years ago|reply
[+] [-] unknown|6 years ago|reply
[deleted]
[+] [-] acidburnNSA|6 years ago|reply
Then the trouble started. They (smartly!) asked MIT to do a design review and a few questions came up on their key claims. Turns out, there were some calculation or assumption mistakes that showed that it couldn't just run directly on nuclear waste (you traditionally need fast neutrons and/or aggressive reprocessing to do this, even in molten fuel) [4]. They adjusted their copy and moved forward with an adjusted design and new calcs. Eventually they decided to close up shop and open source their design effort as a soft closure.
It's highly regular for advanced nuclear efforts to adjust their design and strategy as they move forward. In fact, I'd go so far to say it happens in 100% of efforts. The only thing Transatomic did that might be a lesson learned is that they got really hyped up early on in their effort, before they shook it down with engineering reviews and whatnot.
As far as I can tell, no one is curating progress or roadmaps in the open source effort. I LOVE the idea of open-source reactor design. It gets around huge institutional barriers clogging up opportunities for collaboration and alignment in the nuclear space. Nuclear is traditionally very secretive, and all these startups promising the world in 2024 without collaboration is basically a doomed effort. The industry must team up, find overlapping tech development efforts and facilities, and work together to build a market. Once they build the market, they can worry about competing in it. Open source can also transcend traditional funding cycles, like when national labs work on a reactor for 2-4 years, make tons of exciting progress, and then drop it. If it's open, universities, international institutions, companies, etc. can all coordinate on it.
Doing open source reactor design would require a lean and highly-dedicated non-profit or foundation or something with a handful of nuclear design pros in it to do the coordination. These projects don't run themselves. It would also need lots of legal resources to navigate export control space. Everything Adm. Rickover said in 1953 about academic vs. practical reactors is incredibly accurate to this day [5], and using open-source philosophy to face these facts brutally may be essential for progress in nuclear.
If anyone has ideas on how to fund that kind of thing, let me know.
[1] https://github.com/transatomic/reactor/
[2] https://www.youtube.com/watch?v=AlRhcHNJed0
[3] https://www.newfiremovie.com/
[4] https://www.technologyreview.com/s/603731/nuclear-energy-sta...
[5] https://en.wikiquote.org/wiki/Hyman_G._Rickover#Paper_Reacto...
[+] [-] areoform|6 years ago|reply
But the problem will always be. How do we go from designs to an actual, legitimate organization that can play with nuclear materials in Dyson’s little red schoolhouse? https://blogs.scientificamerican.com/the-curious-wavefunctio...
Funding will always be contingent, in the minds of most readers, the trustworthiness/robustness of a rough path that goes from a brain trust to a prototype reactor. If we can solve that, we could probably get significant funding lined up by 2024
[+] [-] rakoo|6 years ago|reply
Indeed, I always thought that for any company the idea is 5% of the success, everything else is the execution. If a company can use a perfectly working design and just run it (as in PowerPlant as a Service) then that's where the value is, both for them in financial terms and for the society in advancement terms. Commoditize the design of the core reactor and innovate on its different uses and the whole supply chain.
[+] [-] richk449|6 years ago|reply
Edit: I should have your Rickover link before posting. It captures my point in more detail, and with more pith.
[+] [-] gomox|6 years ago|reply
[+] [-] mjewkes|6 years ago|reply
[+] [-] matthberg|6 years ago|reply
[+] [-] nickik|6 years ago|reply
For those interested, Terrestrial Energy and Moltex Energy are somewhat more serious attempts to build molten salt reactors, both are quite different form Transatomic.
Terrestrial Energy and Moltex both are in the regulatory process in Canada (the only place a new reactor can realistically be approved) and Terrestrial Energy is the furthest along of any GenIV reactor in terms of commercial regulation in the Western world.
This talk by the main designer of Moltex is a pretty nice summation why they think it would work:
https://www.youtube.com/watch?v=TvXcoSdXYlk
[+] [-] boutcher|6 years ago|reply
[+] [-] temptemptemp111|6 years ago|reply
[deleted]