An two-dimensional analytical nodal method of multigroup diffusion equation in hexagonal geometry based on symmetric groups theory

Based on analytical representation of nodal flux distribution and symmetric groups theory of regular 2 D hexagon, a new efficient nodal method is developed for the solution of multigroup neutron diffusion equation in hexagonal geometry without resorting to the traverse integration technique. Differing from the commonly used surface average partial current nodal coupling method, nodes are coupled with partial current first moment as well as surface average partial current.An experimental code GTDIF H has been developed based on the proposed model. The dramatic efficiency and accuracy of proposed method is well demonstrated by the numerical results of benchmark problems.