9 ms·

What is a molten salt reactor?

136 points by matt_the_bass 4y ago

jleyank 4y ago
The way modern society is going, a LOT of power is going to be required along with an increase in the distribution network (EV's). Where it comes from, and how the "wires" are made are critical areas of research. Unless some novel research succeeds, distasteful decisions are going to be made to keep things going.
- dane-pgp 4y ago
  > The way modern society is going, a LOT of power is going to be required What do you mean by "modern society"? According to the IEA, "energy demand per capita is likely to remain at current levels for the next 25 years. In other [words], peak per capita energy consumption may have already arrived".[0] Most "modern societies" have less than replacement fertility levels, so energy use is only increasing because the population is living longer, and because of immigration. To give some aggregate numbers for a set of modern societies: "The EU-27’s population is projected to increase from 446.8 million in 2019 and peak to 449.3 million in 2026 (+0.6 %), then gradually decrease to 441.2 million in 2050".[1] [0] https://www.businessinsider.com/bernstein-says-peak-energy-per-capita-is-here-2016-8 https://www.businessinsider.com/bernstein-says-peak-energy-p... [1] https://ec.europa.eu/eurostat/statistics-explained/index.php?title=People_in_the_EU_-_population_projections&oldid=497115 https://ec.europa.eu/eurostat/statistics-explained/index.php...
  - jleyank 4y ago
    When was this study done, as crypto and ev’s are going to throw a whole lot of strain on the power grid (taken from the gas distribution plumbing). In the kcal aggregate, they might be equivalent, but a whole lot of tanks and pipes have to become wires.
  - Manuel_D 4y ago
    Energy per capita, yes. But electricity per capital not necessarily. Things like smelting, shipping, and air travel, all of which depends on fossil fuel must be electrified.
    - zbrozek 4y ago
      I'm actively trying to drive down my marginal cost of electricity explicitly so I can use more of it to make my life better. I am absolutely driving up my total energy consumption, not just switching fuels.
      - PebblesHD 4y ago
        I’m in the process of installing solar panels and storage for exactly this reason. There are things I want to do at home, running servers, air conditioning etc. that are prohibitively expensive and unnecessarily polluting under current conditions that I’d love to be able to run without thinking about it.
        zbrozek 4y ago
        Yup, exactly! I am up to a little over 6 kilowatts peak and 20 KWh installed and I haven't drawn from the grid in months. My next stop is 14 kilowatts peak and 36 KWh. With any luck I'll be able to leave my pool warm for 6 months of the year and remain off-grid.
        2Gkashmiri 4y ago
        Hey. This is interesting for me. I now have a 6 kWh panel that are on grid for reverse metering. Then I replaced the inverter with phocos one so that it will work without batteries in off grid mode. I have thought quite a bit about water batteries, I want to install 200-400 Litre water solar heater so that my electric energy is reduced even more. No batteries yet because they cost a fortune. My idea was to heat say 500 Litre water tank in my basement with solar water + solar electric and pass that water through the central heating piping through he home but installer tells me the heat won't be there in this "water battery".
  - wbl 4y ago
    Demand is a function of cost. There is a lot of things that having energy would permit that right now aren't possible like desalination, giant lasers to launch things to space etc.
- ncmncm 4y ago
  Electric power demand will increase by what it takes to keep our cars charged up, and to drive industrial production of hydrogen for steel and other industrial processes, ammonia for fertilizer, synthetic fuels (including ammonia and hydrogen) for bigger vehicles, carbon capture from the atmosphere, water desalination, and myriad other uses. Build-out of renewables will increasingly displace fossil-fuel generation, then (as that is exceeded) bank energy in storage systems (batteries and pumped hydro, short-term, other tech for longer term). We will need a lot of new transmission lines to trade power between current users, current generators, and storage. None of it requires new physics, although improvements in catalysts will improve round-trip efficiency and cost of storage systems and synthesis, and new chemistries will improve cost and efficiency of new photovoltaic build-out. There is no place for nukes in that world. They cost way too much to compete on a fair playing field.
ncmncm 4y ago
A molten salt reactor is, first and foremost, a distraction. By the time any production molten-salt reactor design could get proved out and the first commercial one built, renewables + storage will be providing all our power for much less money than it ever could. But we can waste a lot of $billions on it that could instead go to build out a hell of a lot of panels and wind turbines.
- acidburnNSA 4y ago
  Or water cooled reactors!
  - ncmncm 4y ago
    One or two, anyway. Eventually, if not cancelled.
- Gordonjcp 4y ago
  - ncmncm 4y ago
    Yet, they really do, and are not.
    - Gordonjcp 4y ago
      Okay, so how far can I drive my car on six hours of daylight on a cloudy day?
- omega3 4y ago
  There are countries where neither solar nor wind are a viable options.
  - pydry 4y ago
    Where?
acidburnNSA 4y ago
See also my thorium myths page https://whatisnuclear.com/thorium-myths.html https://whatisnuclear.com/thorium-myths.html
- Blackthorn 4y ago
  Very nice. Could you add one about the waste cycle? Like, it feels true in one sense (maybe there's less fuel waste that matters, or so the claims go) but way false in another (molten salt is nasty as hell and requires a lot of maintenance which means a lot of irradiated waste).
- mcv 4y ago
  I've been hearing for years now how fantastic Thorium is, but with every new article, I wonder: so where are all these new fantastic Thorium plants? If they still don't exist, then surely that suggests it doesn't work, doesn't it?
  - Stevvo 4y ago
    No, we know Dyson spheres work too... We just didn't get around to building one yet.
  - rpdillon 4y ago
    My current hypothesis is that nuclear became politically toxic in the 80s, and public will to support nuclear research evaporated, leading to everyone thinking "nuclear == light water reactor", and the entire field of research on fission-based nuclear stagnated as a result. I'm not an expert though, just interested in the topic. I read up quite a bit on MSR and LFTR a decade ago and concluded that it was really interesting tech that can absolutely work but just never got enough interest for someone to "go big" with it. The wikipedia article[0] has a recent developments section that suggests the tech is quite viable. [0]: https://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reactor#Recent_developments https://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reacto...
    - mcv 4y ago
m0llusk 4y ago
This boldly claims that molten salt reactors are safe, but my understanding is that these systems require carefully engineered coatings to function and that in practice every such system has leaked liquid sodium. The statement may be essentially true kind of like saying elevators are safe, but there is still room for risk analysis and expectation of occasional failures.
- abracadaniel 4y ago
  Storing and piping molten salt proved too unreliable for the Crescent Dunes solar collector. Swapping out the simple and free heat source with a much more complex nuclear reactor doesn’t seem like a good idea. https://en.wikipedia.org/wiki/Crescent_Dunes_Solar_Energy_Project https://en.wikipedia.org/wiki/Crescent_Dunes_Solar_Energy_Pr...
  - mlyle 4y ago
    Mostly because of problems with foundations and the power-tower architecture. And note that other molten salt concentrated solar plants have done just fine, and that nuclear power is much more highly regulated and requires a higher degree of engineering analysis than a concentrated solar plant (that's why it's so expensive, in large part!)
  - Stevvo 4y ago
    There are multiple other solar plants operating with molten salts without issue, including the biggest in Morocco.
- ortusdux 4y ago
  I've been working on molten salt reactor claddings for a few years now. MSRs are very safe. First, there are two main groups of molten salt systems. One group uses generic salt to transport heat. This usually provides efficiency gains over water based systems. These are the systems that might leak sodium and it's no big deal. The 2nd kind of system uses a salt with the fissile material dissolved in it. This is what the article is about. Leaks in these systems are not an option. The molten salt in this case slowly attacks any metal it comes in contact with. The tanks, tubes, etc. are designed with a large safety margin and constantly monitored. The salt chemistry is also monitored for signs of the materials the storage vessel is made of.
aliswe 4y ago
> In essence, a molten salt reactor [MSR] is a vessel that contains a hot liquid salt which a nuclear reaction takes place The tl;dr on the page is missing a crucial word near "which", making the sentence nonsensical to me.
- mlyle 4y ago
  "in which"

136 points by matt_the_bass 4y ago

The way modern society is going, a LOT of power is going to be required along with an increase in the distribution network (EV's). Where it comes from, and how the "wires" are made are critical areas of research. Unless some novel research succeeds, distasteful decisions are going to be made to keep things going.

dane-pgp 4y ago
> The way modern society is going, a LOT of power is going to be required What do you mean by "modern society"? According to the IEA, "energy demand per capita is likely to remain at current levels for the next 25 years. In other [words], peak per capita energy consumption may have already arrived".[0] Most "modern societies" have less than replacement fertility levels, so energy use is only increasing because the population is living longer, and because of immigration. To give some aggregate numbers for a set of modern societies: "The EU-27’s population is projected to increase from 446.8 million in 2019 and peak to 449.3 million in 2026 (+0.6 %), then gradually decrease to 441.2 million in 2050".[1] [0] https://www.businessinsider.com/bernstein-says-peak-energy-per-capita-is-here-2016-8 https://www.businessinsider.com/bernstein-says-peak-energy-p... [1] https://ec.europa.eu/eurostat/statistics-explained/index.php?title=People_in_the_EU_-_population_projections&oldid=497115 https://ec.europa.eu/eurostat/statistics-explained/index.php...
- jleyank 4y ago
  When was this study done, as crypto and ev’s are going to throw a whole lot of strain on the power grid (taken from the gas distribution plumbing). In the kcal aggregate, they might be equivalent, but a whole lot of tanks and pipes have to become wires.
- Manuel_D 4y ago
  Energy per capita, yes. But electricity per capital not necessarily. Things like smelting, shipping, and air travel, all of which depends on fossil fuel must be electrified.
  - zbrozek 4y ago
    I'm actively trying to drive down my marginal cost of electricity explicitly so I can use more of it to make my life better. I am absolutely driving up my total energy consumption, not just switching fuels.
    - PebblesHD 4y ago
      I’m in the process of installing solar panels and storage for exactly this reason. There are things I want to do at home, running servers, air conditioning etc. that are prohibitively expensive and unnecessarily polluting under current conditions that I’d love to be able to run without thinking about it.
      - zbrozek 4y ago
        Yup, exactly! I am up to a little over 6 kilowatts peak and 20 KWh installed and I haven't drawn from the grid in months. My next stop is 14 kilowatts peak and 36 KWh. With any luck I'll be able to leave my pool warm for 6 months of the year and remain off-grid.
        2Gkashmiri 4y ago
        Hey. This is interesting for me. I now have a 6 kWh panel that are on grid for reverse metering. Then I replaced the inverter with phocos one so that it will work without batteries in off grid mode. I have thought quite a bit about water batteries, I want to install 200-400 Litre water solar heater so that my electric energy is reduced even more. No batteries yet because they cost a fortune. My idea was to heat say 500 Litre water tank in my basement with solar water + solar electric and pass that water through the central heating piping through he home but installer tells me the heat won't be there in this "water battery".
- wbl 4y ago
  Demand is a function of cost. There is a lot of things that having energy would permit that right now aren't possible like desalination, giant lasers to launch things to space etc.
ncmncm 4y ago
Electric power demand will increase by what it takes to keep our cars charged up, and to drive industrial production of hydrogen for steel and other industrial processes, ammonia for fertilizer, synthetic fuels (including ammonia and hydrogen) for bigger vehicles, carbon capture from the atmosphere, water desalination, and myriad other uses. Build-out of renewables will increasingly displace fossil-fuel generation, then (as that is exceeded) bank energy in storage systems (batteries and pumped hydro, short-term, other tech for longer term). We will need a lot of new transmission lines to trade power between current users, current generators, and storage. None of it requires new physics, although improvements in catalysts will improve round-trip efficiency and cost of storage systems and synthesis, and new chemistries will improve cost and efficiency of new photovoltaic build-out. There is no place for nukes in that world. They cost way too much to compete on a fair playing field.

ncmncm 4y ago

A molten salt reactor is, first and foremost, a distraction. By the time any production molten-salt reactor design could get proved out and the first commercial one built, renewables + storage will be providing all our power for much less money than it ever could. But we can waste a lot of $billions on it that could instead go to build out a hell of a lot of panels and wind turbines.

acidburnNSA 4y ago
Or water cooled reactors!
- ncmncm 4y ago
  One or two, anyway. Eventually, if not cancelled.
Gordonjcp 4y ago
- ncmncm 4y ago
  Yet, they really do, and are not.
  - Gordonjcp 4y ago
    Okay, so how far can I drive my car on six hours of daylight on a cloudy day?
omega3 4y ago
There are countries where neither solar nor wind are a viable options.
- pydry 4y ago
  Where?

acidburnNSA 4y ago

See also my thorium myths page https://whatisnuclear.com/thorium-myths.html https://whatisnuclear.com/thorium-myths.html

Blackthorn 4y ago
Very nice. Could you add one about the waste cycle? Like, it feels true in one sense (maybe there's less fuel waste that matters, or so the claims go) but way false in another (molten salt is nasty as hell and requires a lot of maintenance which means a lot of irradiated waste).
mcv 4y ago
I've been hearing for years now how fantastic Thorium is, but with every new article, I wonder: so where are all these new fantastic Thorium plants? If they still don't exist, then surely that suggests it doesn't work, doesn't it?
- Stevvo 4y ago
  No, we know Dyson spheres work too... We just didn't get around to building one yet.
- rpdillon 4y ago
  My current hypothesis is that nuclear became politically toxic in the 80s, and public will to support nuclear research evaporated, leading to everyone thinking "nuclear == light water reactor", and the entire field of research on fission-based nuclear stagnated as a result. I'm not an expert though, just interested in the topic. I read up quite a bit on MSR and LFTR a decade ago and concluded that it was really interesting tech that can absolutely work but just never got enough interest for someone to "go big" with it. The wikipedia article[0] has a recent developments section that suggests the tech is quite viable. [0]: https://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reactor#Recent_developments https://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reacto...
  - mcv 4y ago

m0llusk 4y ago

This boldly claims that molten salt reactors are safe, but my understanding is that these systems require carefully engineered coatings to function and that in practice every such system has leaked liquid sodium. The statement may be essentially true kind of like saying elevators are safe, but there is still room for risk analysis and expectation of occasional failures.

abracadaniel 4y ago
Storing and piping molten salt proved too unreliable for the Crescent Dunes solar collector. Swapping out the simple and free heat source with a much more complex nuclear reactor doesn’t seem like a good idea. https://en.wikipedia.org/wiki/Crescent_Dunes_Solar_Energy_Project https://en.wikipedia.org/wiki/Crescent_Dunes_Solar_Energy_Pr...
- mlyle 4y ago
  Mostly because of problems with foundations and the power-tower architecture. And note that other molten salt concentrated solar plants have done just fine, and that nuclear power is much more highly regulated and requires a higher degree of engineering analysis than a concentrated solar plant (that's why it's so expensive, in large part!)
- Stevvo 4y ago
  There are multiple other solar plants operating with molten salts without issue, including the biggest in Morocco.
ortusdux 4y ago
I've been working on molten salt reactor claddings for a few years now. MSRs are very safe. First, there are two main groups of molten salt systems. One group uses generic salt to transport heat. This usually provides efficiency gains over water based systems. These are the systems that might leak sodium and it's no big deal. The 2nd kind of system uses a salt with the fissile material dissolved in it. This is what the article is about. Leaks in these systems are not an option. The molten salt in this case slowly attacks any metal it comes in contact with. The tanks, tubes, etc. are designed with a large safety margin and constantly monitored. The salt chemistry is also monitored for signs of the materials the storage vessel is made of.

aliswe 4y ago

> In essence, a molten salt reactor [MSR] is a vessel that contains a hot liquid salt which a nuclear reaction takes place The tl;dr on the page is missing a crucial word near "which", making the sentence nonsensical to me.

mlyle 4y ago
"in which"