Transport Calculations of MOX and UO_2 Pin Cells by the Method of Characteristics
A new transport theory code for two-dimensional calculations of both square and hexagonal fuel lattices by the method of characteristics has been developed. The ray tracing procedure is based on the macroband method, which permits more accurate spatial integration in comparison to the equidistant method of tracing. The neutron source within each region is approximated by a linear function and linearly anisotropic scattering can be optionally accounted for. Efficient new techniques for both azimuthal and polar integration are presented. The spatial discretization problem in case of P<SUB>1</SUB>-scattering has been studied. Detailed analyses show that the P<SUB>1</SUB>-scattering in case of regular infinite array of fuel cells is significant, especially for MOX fuel, while the transport correction is inadequate in case of real geometry multi-group calculations. Finally, the complicated nature of the angular flux in MOX and UO<SUB>2</SUB> fuel cells is demonstrated.
- Journal of nuclear science and technology
Journal of nuclear science and technology 35(12), 874-885, 1998-12-25
Atomic Energy Society of Japan