[acidburnNSA]

> The only reason uranium won out over thorium was because the waste was weapons grade and useful during the cold war.

This is such a common myth that it inspired me to write a whole thorium myths page to explain how and why it's not true, back in 2014: https://whatisnuclear.com/thorium-myths.html#myth1

Happy to discuss more but I've said a lot on that page.

[mike_d]

Absolutely said a lot about the technical and economic justifications, but don't really address the political aspect at all. Remember the that decision was made by the AEC, which at the time was heavily influenced by the Military Liaison Committee. Also forgive me if I don't agree that the people who oversaw unethical human experimentation for 30 years and released radiation over my home town might not have made their decision based on the same sound reasoning you lay out.

If you haven't read it already, Dr. Weinberg's memoir does a good job detailing the politics around the demise of the MSR.

[acidburnNSA]

The decision to shut down the Molten Salt Program within the AEC was driven by Milton Shaw, who also and at the same shut down numerous other programs: sodium graphite program (Hallam), organic program (Piqua), superheat BWR (Bonus, Pathfinder), high temperature gas, etc. He shut these down because he wanted all focus to be on the Fast Breeder Reactor (Clinch River). This was all in 1968.

Uranium-fueled commercial reactors never had anything to do with making plutonium for weapons. Plutonium was made by graphite and heavy water moderated reactors at Hanford and Savannah River.

I have read Weinberg! It's my favorite book. It's interesting that at the end he was more excited about the PIUS PWR than the MSR. Here are my reading notes: https://whatisnuclear.com/weinberg.html