Abstract
The objectives of this thesis are to establish Lungmen PARCS model with SNAP interface, and to couple the thermal-hydraulic code TRACE for more advanced calculations in 3D core. This TH/NK calculation is believed to be a “best-estimate” calculation where the local interactions between the nuclear power plant and the core phenomena could be observed easily.In this research, three cases were analyzed using Lungmen TRACE/PARCS model: 3 RIP trip in FSAR, the SCRRI function, and the instability due to control rod perturbation. To analyze the 3 RIP trip, three power generations implemented in TRACE were used respectively, which are power table, point kinetic, and coupled to PARCS. The results from three different power generations are in good agreements with FSAR results. The SCRRI mechanism was performed under several initial conditions and different RIP runback settings, and the power reductions were found to meet the criteria as specified in the startup test procedures. The two instability modes, core-wide and out-of phase, were modeled by control rod perturbations; oscillations of reactor power and fuel assembly inlet flow can be observed.In conclusion, Lungmen TRACE/PARCS model has been completed and can be used for safety analysis. After the commercial operation of Lungmen power plant, this coupled code would be verified. In addition, the experiences of completing Lungmen PARCS model can promote the establishments of the PARCS models of other three nuclear power plants.