Coarse-mesh three-dimensional transport calculation method

A coarse-mesh 3-D (X-Y-Z, Hexagonal-Z) discrete ordinates transport calculation method has been developed. This method employs an weighted diamond difference approximation, the weight in which is a function of neutron direction and scalar flux, and can be easily incorpolated into conventional discrete ordinates transport codes. Results obtained in four-group S4P0 calculations on simple fast reactors indicate that, though the computer time of this method has increased by 30 ∼ 50 % compared with that of the conventional finite difference method using the same mesh, the errors of keff and the power distribution are reduced remarkably. (author)