A neutron transport analysis code, STREAM (Steady state and Transient REactor Analysis code with Method of Characteristics), has been developed to perform a whole LWR core calculation with the direct transport analysis method and the two-step method. Numerous advanced features, especially resonance treatment methods, have been developed and implemented in the STREAM code for higher accuracy and performance. STREAM with the advanced methods has order of ~100 pcm accuracy in LWR analyses. STREAM has capabilities to analyze the whole LWR core through the two-step (with PARCS or RAST-K 2.0) method and direct transport method (2-D).
The RAST-K 2.0 code is a recently developed three-dimensional two-group PWR core analysis code by UNIST CORE lab. It aims to be used by utilities to perform in-core fuel management studies, core design calculations, load follow simulation and transient analysis in neutronics. The RAST-K 2.0 code is capable of performing steady-state, quasi transient and transient calculations by solving the two-group three-dimensional neutron diffusion equation in eigenvalue or fixed source modes.
A Monte Carlo code MCS has being developed at Ulsan National Institute of Science and Technology (UNIST) since 2013. The target of MCS is to solve complex whole core problems like BEAVRS. MCS can treat the 3D whole core geometry with universe and lattice, and the neutron physics with probability-table, free-gas treatment, S(a,b) and Doppler Broadening Rejection Correction.