A Numerical Technique for Solving Group Diffusion Equations

An efficient method for solving group diffusion equations is described. Application of the Perron Frobenius theory of non-negative matrices allows a direct determination of reactor criticality without calculation of neutron fluxes. Higher flux modes may also be found. Simultaneous calculation of all flux groups simplifies formulation with inelastic- and up-scattering, and also provides a convenient tool for some kinetics studies.