[en] Various ''alternative'' fuel cycles have been proposed to alleviate concerns about reactor fuel being diverted for the manufacture of nuclear weapons. This report addresses the impact of such fuel cycles on the performance of the classical (homogeneous) oxide-fueled Liquid Metal Fast Breeder Reactor. The primary fuel cycle analyzed is the ²³³U/²³⁸U/²³²Th fuel cycle in which the fissile component ²³³U is ''denatured'' with ²³⁸U in order to restrict the use of reactor fuel as a source of weapons-usable material. The denatured reactor performance as a function of the fissile enrichment (% ²³³U in U) is evaluated. The associated energy center concept in which dispersed denatured reactors are coupled to ²³³U production reactors operating in such secure energy centers is described. The symbiotic system of dispersed/energy center reactors is analyzed both from the standpoint of energy growth supported and dispersed/centralized power production. Lastly, the effects of proposed changes in the nuclear data on both the reactor performance and symbiotic system characteristics are addressed