Advanced modelling methods in Monte Carlo

In the WIMS7 reactor physics program scheme a three dimensional microscopic depletion method has recently been developed, using Monte Carlo fluxes. Extensions of the method enabling users to evaluate reactivity coefficients and point powers have also been added. These methods, which include whole core calculations, have been implemented in the long established companion code MONK5W. Predictions at successive depletion time steps are thus based on a calculational route where both geometry and cross sections are accurately represented, providing a reliable and independent reactor physics analysis package for benchmarking other methods. Newly developed tracking and storage procedures in MONK5W enable whole core burnup modelling on a desktop computer. Theory and applications are presented. (author)