Moosey - I can understand that GEH may have had aspirations to...

Moosey - I can understand that GEH may have had aspirations to sell PRISM to the UK but I cannot find any reference (or reason) that this could/would have extended to GLE (or Silex) being involved in any way with "refining" the RepU which as I understand it only had less than 1% ²³⁵U in it with also a significant amount of ²³⁶U (~0.5%) also present in that RepU. The resonant v3 frequency for ²³⁵U is 15.916 micron but for ²³⁶U it's 15,922 microns and at the cryogenic temperatures for separation these frequency band still considerably overlap; consequently I fail to see how our technology could efficiently separate ²³⁵U for ²³⁶U (it's good for separation of ²³⁸U from ²³⁵U due to the v3 frequency having a 0.018 microns separation (not 0.006 microns) where the 238U band is significantly attenuated at cryogenic temperatures). For lower atomic number elements (e.g Si) the v3 separation bands are significantly wider but still for zero spin Si (e.g ²⁸Si) in stripping the ²⁹Si we also take out the ³⁰Si (since the v3 frequency is biased towards removing primarily the ²⁹Si but also gets the ³⁰Si (this was alluded to by MG at the 2023 AGM to a question on the topic).

Maybe you can provide some insight on how the v3 freuency bands for ²³⁶U and ²³⁵U can be separated (at cryogenic temperatures) to re-enrich RepU (with less than 1% ²³⁵U present) possible ignoring the possibility that (with less than 1% ²³⁵U) it would be economic. I can understand that reprocessing RepU from spent HALEU (with about 7% ²³⁵U present) or spent EBR-II RepU (with about 60% ²³⁵U present) could possibly be economic (ONL (and BWTX) currently just downblend this RepU - the ²³⁶U is NOT removed).

I can understand the rational for putting RepU into a fast reactor (where it fission's) but I cannot understand how re-enriching ²³⁵U from spent LEU RepU could be economic and also how our technology could do it given the tiny (0.006 micron) separation of the v3 bands and their overlap. maybe you can explain to me where I am wrong (I can understand reprocessing to remove the fission products and higher actinides including Pu - as in the ARC)