Development and Verification of Modular 2D/1D Coupling Characteristic Line Method MMOC Code

Based on the idea of coupling solution, the method of characteristic line (MOC) is applied in both axial and radial directions. By carrying out the 2D/1D coupling MOC theory and modular geometry preprocessing method, a 2D/1D coupling neutron transportation code MMOC was developed, and the 1D/2D/3D C5G7 benchmark was verified. The relative errors of k_eff are 0.082%, 0.045%, and 0.032%. The MMOC code is reliable and can satisfy the computational requirement of neutron transportation.