I have been waiting for about 20 years for this paper to appear.

[NNadir]

6. We desperately need as much plutonium as we can get.

There are almost 60 metals in the periodic table available in macroscopic quantities, and iron is only one of them.

The current paper proposes to use tungsten, which would have the interesting property under these conditions to be transmuted over a period of time into the very valuable and very rare metals rhenium, osmium, iridium, and even platinum.

Beyond specific metals, there is also a huge and very advanced science called "Materials Science" that is way more sophisticated than when the LAMPRE reactor operated in the 1950's and early 1960's. (It did not leak.) There are many concepts that can be utilized to manage hot liquid plutonium, for example, metalloceramics, certain classes of metallocarbides, very corrosion and temperature resistant nitrides, as well careful design to exploit peritectic systems to make plutonium migration into metals be effectively self healing.

My son is a materials scientist and he is, in fact, working on nuclear materials in a nuclear engineering program.

The point of a liquid plutonium fueled reactor is that to allow continuous reprocessing without removing or isolating the fuel. Under these conditions we could recover valuable fission products by rather mundane chemical processes on line, such as distillation and extraction.

Note, the LAMPRE did not operate on pure liquid plutonium but actually the fuel was an iron/plutonium eutectic. The reactor exploited the solubility of iron in plutonium.

The point of having more plutonium is to save what is left to save from climate change and fossil fuel related chemical pollution, and perhaps to restore what can be restored. It can be shown that converted to plutonium, the world inventory of uranium already mined, which is mainly ²³⁸U. Plutonium is, I have convinced myself, the last best hope of the human race. The question is to make it fast enough to accomplish this vital task. Liquid plutonium can exhibit very high breeding ratios, perhaps only exceeded by some americium isotopes, although this data should be subject to update.

Without plutonium, to my mind, there isn't all that much hope for the future.