A hybrid diffusion/transport method

A hybrid diffusion/transport method is presented in this paper. The traditional diffusion theory is used for regions where the diffusion approximation is valid, while response functions pre-computed by a local transport solver are used for non-multiplying regions or regions with strong heterogeneities, where diffusion theory breaks down. The two methods are coupled through the 0th and 1s't moments of the partial angular flux on the interface between the diffusion and transport nodes (coarse meshes). The hybrid method was implemented and tested on a one dimensional BWR benchmark problem. This test has shown that the hybrid method can achieve high accuracy while maintaining a computational efficiency comparable to the pure diffusion methods. (authors)