science

MSRs are a boondoggle, a waste of effort.

What are the claimed benefits? Simplified piping, abundant fuel, self limiting power, etc.

Trivial engineering counterpoints:

• Piping remains extremely complex, the activated thorium becomes U235 eventually, irradiating the hell out of the entire system. How do you change a valve when it gets damaged? You have other valves, and bypasses, and check valves, and... ~~Piping is simpler~~.
• Abundant fuel.. we keep extracting from the Earth, and cutting huge ugly gashes in her. Let's not.
• Self-limiting power... Some materials are very, very corrosive by themselves. Want to make them nastier? Add energy to them in the form of heat. MSRs use Sodium or Fluorine salts, both of which strongly react with water in the atmosphere, if not the air itself in an exothermic manner. And they do so with a bang, under the right conditions. So yeah, self limiting. But at a very risky cost.
• materials: prior reason also effects material selection. Inconel is expensive, and very damn hard to machine, even with our modern carbide tooling. Materials keep coming along, and maybe that'll reduce cost. But just like fusion, it's a maybe.

MSRs: nah.

Extracting energy from fusion: some systems can be solid state. Depending on the process and the inputs, it's possible to directly extract electrical energy from neutrons crossing a charged grid, and dump that power (after some filtering and such) right into the national electrical grid, no steam needed.

Need to find a working fusion reactor? Look up.