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First US molten salt reactor in over 50 years to be built (www.businessinsider.com)

submitted 10 months ago by [email protected] to c/[email protected]

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One study suggested that the reactors could produce more nuclear waste than current systems and that they "will use highly corrosive and pyrophoric fuels and coolants that, following irradiation, will become highly radioactive."

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[–] [email protected] 59 points 10 months ago* (last edited 10 months ago) (1 children)

If you can work it properly, molten salt reactors are MUCH safer and more efficient, because the waste heat from fission products cannot cause a problem with something cooled through convection and conduction of a molten salt. You can't really have a destructive meltdown when the coolant doesn't care if the fuel melts. The problem is, most previous attempts ended up with the reactor catching on fire. Not a dangerous fire, exactly, but generally not the outcome you're looking for.

On the waste front, neutron activation of water produces tritium at worst, which you dispose of by putting it into a bigger body of water. Neutron activation of the molten salt coolant can be more difficult to dispose of, but it's not exactly a major problem.

[–] [email protected] 2 points 10 months ago (1 children)

If we could use the tritium that would be helpful, it's limited on earth and our only known source off world is in lunar regolith. Plus it's part of the fuel needed to begin a fusion reaction.

[–] [email protected] 3 points 10 months ago* (last edited 10 months ago)

It's not a lot of it and isolating it is more trouble than it's worth. It's easier to just create a lithium channel that creates it when it's neutron activated. That or isolating it from a heavy water reactor, since that produces a whole lot more.

Tritium isn't scarce, in that we really can create it pretty easily. Lithium-6 is available to do so if needed. (https://isotope.com/en-us/lithium-6-metal-li-95-pct-llm--827--pk). It's jut not economical to produce for most purposes.

Edit: Also, it's not tritium in the regolith but He3, which is theorized as an aneutronic (thus much cleaner and not creating a bunch of neutron activation waste like tritium fusion would create) fusion fuel but nobody's really achieved fusion with it. Tritium would've decayed if it was in the regolith.

When you let tritium decay, it creates He3.