Investigations to optimise the utilisation of spectral conditions in boiling water reactors with new fuel concepts

The majority of commercially operated nuclear power plants worldwide are thermal light water reactors, such as pressurised and boiling water reactors. For neutrophysical reasons, the fuel utilisation of boiling water reactors is inefficient in the upper ranges of fuel elements. Results of investigations of a method are presented, one that exposes isotopes to light neutron moderators with a favourable ratio of microscopic fission and absorption cross sections in fast energy sectors. This means that the fission rate and the transmutation for long-life isotopes are increased and so also the fuel utilisation in the higher range of the fuel assemblies without removing reactivity from the core. (orig.)