Development of Advanced Neutronics Code SCAP-N for Reactor Core High Fidelity Simulation

Reactor core neutronics calculation is important for the reactor design and analysis. In order to improve the resolution and accuracy of the reactor core neutron transport simulation, the advanced neutronics code SCAP-N was developed. In this code, firstly, the core was divided into layers according to the axial characteristics. Secondly, the two dimensional neutron transport calculation was carried out for each layer. Then the homogenized cross sections of all cells were obtained using the super homogenization method. Finally, the three dimensional pin-by-pin transport calculation was carried out to obtain the core effective multiplication factor and the pin power distribution. In order to improve the calculation efficiency, the MPI/OPENMP hybrid parallel method was adopted. The VERA benchmark problems and the AP1000 reactor start-up physical testing problem were used to verify the code. Numerical tests show that the pin-by-pin transport technology adopted by SCAP-N can improve the accuracy of core neutronics calculation compared with the commercial nuclear design system, and SCAP-N has higher computational efficiency compared with other high fidelity neutronics codes, which can further improve the economy and operation flexibility of nuclear power plants.