Satisfying boundary conditions in three dimensions: addendum

In a previous paper, the Distorted Buckling Method was developed, which is an approximation allowing boundary conditions to be satisfied everywhere in the case of the I-group diffusion equation, solved with separable functions in cartesian coordinates. The approximation requires an alteration of the buckling in the corner regions of the reflector. Comparison of the fluxes in the case of a 2-dimensional rectangular core, between the approximation and the predictions of the diffusion code CITATION, showed good agreement except in the case of the corner regions where the approximation gave a significantly more rapid falloff with increasing distance from the core. The example core, however, did not satisfy the requirements of diffusion theory. We herein report on a better example in this regard, which predicts even closer agreement between code and the approximate theory.