Obtaining the neutronic and thermal hydraulic parameters of the VVER-1000 Bushehr nuclear reactor core by coupling nuclear codes

Abstract In this research, the simulation of one-sixth of the VVER-1000 reactor core is carried out by the WIMS-D4 nuclear code, based on the symmetry of the core and information obtained from the Final Safety Analysis Report. The atomic densities of some important nuclear materials and fission poisons are calculated by the WIMS-D4 code at the end of the first fuel cycle. In addition, the cross sections of some nuclides are obtained by WIMS-D4, and they are transferred into the CITATION code as inputs. In the next stage, neutron flux and reactor power are calculated by the CITATION code in Cold Zero Power and Hot Full Power status, and subsequently the heat flux of the core is obtained. Then the results are returned again into the extended program cycle. Finally, the heat flux of the core is inputted into the COBRA code, and the temperatures of fuel, clad and coolant are calculated along the various distances applying the COBRA thermal hydraulic code, through the results of the CITATION code and also initial data as default created from the Final Safety Analysis Report. In conclusion, there are some interesting outcomes resulting form the obtained results.