Comparative Analysis of Nodalization Effects and Their Influence on the Results of ATHLET Calculations of VVER-1000 Coolant Transient Benchmark Phase 1

In this paper, the results of the investigations on the nodalization effects for the ATHLET code are presented and discussed in details on the basis of experimental data for the VVER-1000 Coolant Transient Benchmark with different operating modes of four main coolant pumps. ATHLET calculations with different nodalization and their impact was analyzed. The work studied the in?uence of annular outlet nodalization on calculation of coolant temperature. By comparing the test data versus calculated by ATHLET we showed a good agreement between the experimental data and simulation results for analyzed parameters.