The future development of Fission Reactors

and their fuel cycles


G. Kessler


retired from the former Institute for Neutron Physics

and Reactor Technology

Forschungszentrum Karlsruhe





The present technology of Light Water Reactors (LWRs), Heavy Water Reactors (HWRs, CANDUs) and High Temperature Gas Cooled Reactors (HTRs) as well as Fast neutron Reactor (FRs) or Accelerator Driven Systems (ADSs) will be further developed with regard to their fuel burnup, to their safety concept and to their fuel cycle concept. Presently dominating LWRs and CANDUs are  operated with intermediate storage and direct disposal of their spent fuel element (open fuel cycle in USA, Germany, Russia). For a smaller number of these present LWRs the spent fuel elements are reprocessed followed by plutonium recycling (closed fuel cycle in France, Japan).


Research on actinide incinerations will lead to fuel cycle options with fuel elements containing - together with uranium or thorium - fissile isotopes like U-233, U-235, and transuranium elements (TRUs) like plutonium, neptunium, americium with similar enrichments as present low enriched (U-235) fuel elements. Such fuel cycle options offer also improvement of their proliferation resistance.


FRs and ADSs with a closed fuel cycle are more efficient in destroying actinides than present thermal converter reactors (LWRs etc.). Although they were built and operated already in small numbers in Russia, France and Japan they will only be developed to a larger extent during the second half of this century.