Recycling minor actinides brings about several adverse effects. In response to the effects on cycle operations (fabrication, reprocessing, transportation) due to decay heat and to alpha, beta, gamma, and neutron activities, neptunium brings no significant ill effect, while americium calls for enhanced protection; the large amount of curium activity makes any recycling of this element extremely difficult. In so-called homogeneous recycling (minor actinides mixed with the fuel), the worsening of safety parameters such as coolant void or Doppler effect sets stringent limitations on the minor actinide content: ≈1% in pressurized water reactors and ≈2.5% in large fast reactors. The heterogeneous recycling, i.e., placing the minor actinides in a few special subassemblies at core periphery, brings about lesser penalties and allows higher contents. In any case, fast reactors are better suited to minor actinide transmutation than light water reactors. Fission products are very difficult to transmute efficiently, even in fast reactors. Such fission products should require the use of hybrid systems for their elimination. Finally, a nuclear park is built up in which the plutonium + minor actinide production of light water reactors is consumed in advanced fast reactors. The amount of electrical power generated by these fast reactors is ≈20%. The radiotoxicity reduction achievable can be of a factor 50 with a 1% loss of minor actinides during reprocessing.