Sodium won’t boil at any of the temperatures it should be exposed to

Monday, November 29th, 2021

TerraPower, a US-based nuclear power company backed by Bill Gates, has selected Kemmerer, Wyoming — population roughly 2,500, and home to the soon-to-be-closed coal-fired Naughton Power Plant — as the site for its first reactor:

The TerraPower project will see it replaced by a 345 megawatt reactor that would pioneer a number of technologies that haven’t been commercially deployed before.

These include a reactor design that needs minimal refueling, cooling by liquid sodium, and a molten-salt heat-storage system that will provide the plant with the flexibility needed to better integrate with renewable energy.


The reactor design is being developed jointly with GE Hitachi Nuclear Energy. A company called Bechtel will help with the construction, which will require a workforce equivalent to roughly 80 percent of Kemmerer’s population.


To begin with, the plant will not use water to transfer heat out of the reactor; instead, it will use liquid sodium. This has a major advantage in that sodium won’t boil at any of the temperatures it should be exposed to in the reactor. This means that none of the hardware that holds the coolant will be exposed to high pressures, which simplifies matters considerably. Sodium will, however, readily react with air and explosively react with water, which raises a distinct set of concerns.

Globally, only about 25 major reactors have been built using sodium coolant. Many were only built for research purposes, and only a handful remain operational. The last one in the US was built in 1965, and the last operational one was shuttered in 1994. So, it’s fair to say that the companies don’t have much hands-on experience to draw on.

Sodium-cooled designs, in contrast to water cooling, don’t slow the neutrons produced by fission reactions down; they’re often referred to as “fast reactors” for that reason. Fast neutrons have the ability to transform isotopes that don’t make useful fuel, allowing them to produce more fuel during operation.

In TerraPower’s case, its design surrounds a core of enriched fuel with lots of less-useful isotopes. The reactor will be powered by the enriched core as it converts additional material to useful fuel, which will take over as the first gets exhausted. This process can repeat through several layers of conversion, limiting the downtime needed for refueling. But again, it hasn’t seen commercial use before.

The reactor will have a number of features that should allow passive safety, causing its internal heat to remain limited even if cooling circulation fails.

Finally, TerraPower won’t directly convert the heat extracted from the reactor into power; instead, it will store it as molten salt. As a result, although the reactor will be rated as 345 MW, the plant will be able to generate as much as 500 MW during periods of high demand or scale down to lower production when demand is reduced. This will allow the plant to better follow daily cycles of demand. In addition, the heat storage will also allow the Kemmerer site to better integrate with the growing use of renewable power (Wyoming is a major producer of wind power).


  1. Gavin Longmuir says:

    the heat storage will also allow the Kemmerer site to better integrate with the growing use of renewable power”


    the heat storage will also allow the Kemmerer site to compensate for the unpredictably unreliable power supply from the politician-mandated growing use of heavily subsidized so-called “renewable” power which is causing immense environmental harm, from child workers in African cobalt mines to children poisoned by lithium mining in Mongolia to dead endangered birds in Wyoming.

  2. VXXC says:

    Let’s try: certain soon to be shuttered coal plant and unlikely to open or stay open salt/sodium nuke plant.

    This entire matter of Green going Nuke is hilarious, of course not. They have gone nuclear because they remain anti-nuclear, if nuclear power had replaced coal we’d being going coal burning for ‘no nukes’. Perhaps we’d call it clean coal.

    We will just go dark, as will Kemmerer, WY.

    Honestly people this dumb and weak can die shivering in the cold.

  3. Gavin Longmuir says:

    VXXC: “Honestly people this dumb and weak can die shivering in the cold.”

    Hey! Some of my friends are German! (smile).

    Actually, look at what the Green Extremists have done in Germany, with the approval of the German people. Shut down nuclear power plants because … not quite sure, maybe something to do with the well-known German tsunami risk. But they still need electric power — so they are building replacement power stations fueled by nasty low-rank brown coal. Presumably, it makes sense to someone. (shrug)

  4. Slovenian Guest says:

    Gavin Longmuir,

    The social democrats and greens just formed a governing coalition in Germany and agreed on a 2030 coal exit, too. They also want to lower the voting age to 16. So, no nuclear, no coal, and their energy regulator halted the certification process for the Nord stream gas pipe line, so that wont come online this year, either. I guess the Germans should just all become climate monks and dig for bugs in the darkness and cold.

  5. Sam J. says:

    Liquid sodium reactors are stupid. Why would you put an exploding liquid in a reactor????

    Now if this was the “only” way, maybe, but molten Salt reactors can be used that don’t explode and can be continuously refueled because the fuel in in the salt.

    I’m not against nuclear power just power plants that can explode.

    And if they want a fast reactor the Russians have a great design that uses lead that has been working fine for a long time. Not to mention you can make fast molten salt reactors f you wish also.

    The reason they refuse to use molten salt reactors is it ruins their profit stream. They burn almost every single bit of the nuclear material as opposed to 2% or so in light water reactors and they can be refueled by slowly adding a little liquid as they run.

    The light water reactor folks only make money on fuel not on building plants.

    And if you don’t like molten salt reactors there’s Adams Atomic engines reactors that run off of balls of ceramic with embedded nuclear fuel and the power comes from gas turbines running heated air.

    None of these I mentioned explode.

  6. Pseudo-Chrysostom says:

    “Liquid sodium reactors are stupid. Why would you put an exploding liquid in a reactor?”

    Why would you put exploding liquid in your car?

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