40 Treatment of uranium, namely, enrichment of uranium; chemical refining; chemical enrichment to separate isotopes; enrichment services for producing nuclear fuel in the field of nuclear energy; isotope enrichment services; uranium enrichment services, namely, enrichment and blending of uranium; nuclear fuel processing; treatment of materials, namely, uranium enrichment, uranium conversion, uranium re-conversion, and uranium deconversion; fuel fabrication, namely, converting enriched uranium into fuel for nuclear reactors