[en] The following issues are addressed: problems in ''post-attribute'' development of a methodology for assessing the proliferation resistance of nuclear power systems; the inherent proliferation resistance of the front end of the denatured thorium cycle; and irradiation of fresh LMFBR fuel as a means of increasing the proliferation resistance of this cycle. The calculation presented here assumes pre-irradiation to 1% of maximum burnup (100,000 MWD/MT or 1000 MWD/MT)