DNTM/R2D, 2-D Transport in X-Y Geometry

1 - Description of program or function: DNTM/R2D solves the neutron transport equation in two-dimensional X-Y geometry by the discrete nodal transport method. Source and eigenvalue problems can be solved. As compared to the two-dimensional nodal transport code DNTM/2D, the following new improved features are included: - Anisotropic scattering is considered. The order of anisotropic scattering is from P0 to P3. - The cross section input format is the same as for ANISN. Multi- group cross section libraries such as DLC-37 and DLC-BUGLE-80 can be used. 2 - Method of solution: DNTM/R2D uses the discrete nodal transport method. Anisotropic scattering is treated using Legendre expansion. Order of interior flux approximation is 2. Plane leakage approximation of surface flux is used. 3 - Restrictions on the complexity of the problem: Maximum number of: anisotropic scattering order = 3; material composition = 20; energy groups = 2; angular quadrature = 8; zones = 30. When coarse-mesh re-balancing is used, the maximum number of coarse meshes is 12 in each direction. If the computer permits some arrays can be enlarged to reduce the above restrictions.