Typical benchmarks verification of neutron kinetic code cosKIND for the simulation application of nuclear power plant

The self-developed physical calculation code for CAP1400 FSS needs high accuracy and efficiency. The solver of cosKIND, which based on the NEM and fully implicit finite difference method, is tested by the TWIGL and LMW benchmarks. Special interfaces are set up and the test uses the three-dimensional axial reflection boundary model to simulate the two-dimensional core problem and uses the linear section of each mesh to simulate the movement of control rods. It shows that the overall calculation results are smaller than the reference, the accuracy satisfies the demand of the simulation, and the accuracy basically meets the trends over the time step and the meshing size. However, the method of cross-section introduction should be improved to reduce the errors when the solver uses longer time steps, and the same results are founded in the reference. This test provides quantitative analysis for the development of the solver and improvement suggestions for the application of cosKIND to FSS. (authors)