A new method of benchmarking diffusion codes

Although a simple analytic solution in 2 or 3 dimensions to the diffusion equation for a uniform reflected reactor does not exist, a particular analytic solution is illustrated which requires a non-uniform reflector. Diffusion codes can model such a reactor, and can be compared with the analytic solution, as is shown using the code CIT A TION. This constitutes a new method of benchmarking such codes in 2 or 3 dimensions