Mon 9 Feb, 2015 02:04 pm
In an MSR, the fuel and ~40 other elements are dissolved in the salt. Some isotopes are reaction-killing neutron eaters. Some may be corrosive or have low solubility - plating out on the inside of the heat exchangers. Fuel nuclei can fail to split, and instead become long lived waste. Some of these might be removed from the liquid salt stream as the reactor is running - a major advantage of a liquid fueled reactor. Currently, the processes being discussed are vacuum distillation and over-fluorination. The salt involved is probably going to be "flibe" - lithium and beryllium fluoride, at 450-700 degrees C.
My question is, what can electroplating remove from the stream? Elements of particular interest are the neutron poisons, plus the low solubility jewelry metals, plus the heavy "waste" (Cd/Sm/Eu/Gd + Ru/Rh/Pd/Ag + Pa/Np/Pu/Am/Cu). If we can remove the neutron poisons, the heavy stuff can stay in the salt for years, giving it a chance to become fuel - a real win-win scenario! Also of interest are the thirty-year isotopes, 90-Sr and 137-Cs. (The behavior of all the valence 1 and 7 elements in a fluoride salt needs more study.) Extracting Mo could provide all the medical Tc we would ever need. Adding Thorium could provide the world with a near inexhaustible source of energy.
Any ideas, or suggestions for who else to ask?