Diffusion theory methods for spatial kinetics calculations

Methods for solving the time-dependent neutron diffusion equation for nuclear reactor analysis are discussed. Techniques for treating the spatial variables, as well as techniques for performing the time integration, are described. A major advance made in the treatment of the spatial variables over the past 20 years has been the development of the transverse-integrated class of nodal methods, and thus these methods are described in considerable detail. Finally, results for selected standard benchmark problems that have been obtained using a variety of spatial kinetics methods are compared. (author)