Fluid Fueled Reactor Research Rabbit Hole
Fantastical Fission Futura
http://moltensalt.org/whatIsMoltenSalt.html
It feels like I always had the intuition fission energy was the clear next step on our journey through this cosmos. Harnessing the potential energy released by decaying atomic nuclei—forged within supernova explosions—is the largest lever of action humans have thus far discovered. I can’t tell if it is a tragedy or cosmic comedy that the efforts to utilize the energy of fission to access universal abundance and prosperity of resources was constrained into what exists today.
Where I understand the concerns associated with today’s technologies, there was technology conceived and built in the 20th century which was 100s of times better in every way than what we have today. Soley shuttered for political gain and nearly forgotten to time.
When I discovered molten salt reactors (MSRs), I could hardly believe we had found magic matter and then nearly forgot about it. I watched hours of video, devouring everything I could find on the subject.
MSRs are a type of nuclear reactor that use superheated salts as a coolant and fuel. Fluid fuel has a number of advantages over traditional solid fuel nuclear reactors that use water as coolant. MSR’s low pressures, and high temperatures make them more efficient, safer, all while enabling isotopes it produces to be extracted for advanced application reducing waste to near zero.
I read, watched, and listened for months, each day my conviction that this untapped potential was required to level up humanity to their next stage of exploration grew stronger.
I relearned that the earths molten core and magnetic field, are powered by fission energy and the decay of heavy radioactive elements. This notably makes geothermal energy nuclear energy by proxy.
MSRs are much safer than traditional nuclear reactors, which are already the safest for of energy already. MSRs are inherently stable and cannot melt down. They burn up nearly 100% of their fuel, produce almost no waste, which itself is easier to manage, and refine into industrial products.
MSRs could be used to produce hydrogen, which is important in clean refinement of iron and steel, can be used as a fuel for transportation, and many other industrial processes.
MSRs also produce rare industrial isotopes used in medicine and advanced physics research. I feel excitement when I think about building a more resilient future for my daughter in the form of MSRs. I believe that they have the potential to upgrade humanity and life as a whole.
What Are Molten Salts?
Molten salts are super materials with valuable properties that have enabled a wide range of technologies. Molten salts are simply heated past their melting point to form a liquid. For instance, sodium chloride (table salt) melts at 801°C (1474°F) and becomes a stable liquid with heat capacity and flow properties comparable to water.
One reason why molten salts are special is their versatility. Unlike water, molten salts contract when they solidify, meaning they don’t pose the risk of bursting pipes upon freezing. Their ionic bonds make them chemically stable and possess remarkable catalytic properties.
Features and Applications of Molten Salts
Electrical Conductivity: Solid salts like sodium chloride are insulators, but when melted, their dissociated ions conduct electricity efficiently. This property is used in processes like the Downs Cell, which produces metallic sodium by running electricity through molten sodium chloride.
Heat Transfer: Molten salts are widely used in heat transfer applications. One of the most prominent examples is the Solar Power Tower in California, which uses molten salts to store solar heat for electricity generation.
Chemical Processing: From cleaning metals to decomposing chemical weapons, molten salts’ high temperatures and oxidative properties make them invaluable. For example, Whirlpool uses molten salts to strip paint from appliances for recycling.
Fuel Cells: Molten carbonate fuel cells employ molten salts as electrolytes, enabling electricity generation directly from carbon-based fuels like methanol or gasoline which promises efficient energy conversion.
Coal Gasification and Hydrogen Production: Molten salts enable processes like coal gasification, producing synthesis gases (CO and H2) that serve as feedstock for hydrogen production. This positions molten salts as key players in our hydrogen economy.
Nuclear Reactors: Molten salts’ most exciting application is in nuclear reactors. Originally pioneered through ORNL’s Aircraft Reactor Experiment to the Molten Salt Reactor Experiment (MSRE), these systems have demonstrated inherent safety, high thermal efficiency, and the ability to burn existing nuclear waste while producing minimal new waste. With features like meltdown-proof designs and non-proliferation capabilities, MSRs embody the promise of a sustainable nuclear future.
Key Advantages of MSRs
Coolant and Fuel Medium: MSRs use molten salt, a liquid-state mixture of elements like NaCl or FLiBe (a lithium-beryllium-fluoride mix), to dissolve nuclear fuel. This setup enhances thermal efficiency and simplifies the reactor design.
Inherent Stability: The molten salt itself acts as a natural heat sink, preventing overheating and eliminating the risk of meltdown.
Reduced Waste: Unlike traditional reactors, MSRs burn up most radioactive fission products, producing less long-lived waste that requires storage.
Hydrogen Production: MSRs can produce hydrogen cleanly, either through water-splitting electrolysis or thermal catalytic processes, making them versatile beyond electricity generation.
The legacy of molten salt technology spans over two centuries, from Sir Humphry Davy’s early experiments in electrolysis to modern-day innovations in renewable energy and nuclear power. As we look to the future, molten salts stand as a testament to the ingenuity of science and humans potential to build a better future for generations to come.
MSRs of any kind will make a major contribution to the fight against low energy density sources. They are a clean, safe, and efficient way to generate electricity. I feel excited when I think about the future of MSRs, they will change the world for the better.
A common rebuttal I’ve heard is “If this technology is so great, why wasn’t it developed?”
Here we have a fun answer in the form of a podcast format generated by Google Illuminate. Based on this paper: Why MSRs were Abandoned - ORNL
Further Reading: Status and Potential of MSRs.
Here again in a podcast format:
Finally.
My favorite chapter of the Fluid Fueled reactor paper: Nuclear Aspects of the MSR.
There is a lot to think about here. Imagine how many kinds of combustion engines have become possible given sufficient development. Similarly, there are potentially more MSR variants than combustion variants.
Another surmountable challenges to overcome long term is to be able to make changes to the core and its systems remotely. Back in the day they could do this manually and mechanically. Now we can do it digitally.
Finally, here is the whopper of a documentary which changed the way I think about nuclear energy, molten salt technology and Thorium.
I know it’s a lot but if you want the future to be bright, you want it to be fission powered. Let us not waste this gift given to us by 20th century scientific acceleration! Demand more better technology, think about it, build it, refine it.