development and implementation of 3d algorithm of neutron transport solution via 2d(moc) /1d(nem) fusion method

Progress in nuclear engineering, as a highly interdisciplinary field, along with evolution in computational software and hardware, gives authorization to 3d transport simulation of highly heterogeneous generation iv reactor cores, instead of 3d diffusion calculation. to improve the computational efficiency of 3d neutron transport, fusion methods(2d/1d) are being considered. these methods offer a lower computational cost compared to the common methods, in which the 3d neutron transport kernel is divided into two separate kernels for each radial and axial direction since the material heterogeneity is not the same in these two directions. due to its lower computational cost, the implemented 2d/1d method uses the nodal diffusion expansion method (nem) as an axial kernel in this research. meanwhile, the radial direction was analyzed using the method of characteristic (moc) utilizing modular ray tracing as the transport kernel because of the higher heterogeneity in this direction.  simulating the well-known takeda model 1 benchmark has evaluated the implemented algorithm.