Analysis of the Pressurized Water Reactor Main Steam Line Break Benchmark by the Coupled Code System ATHLET-QUABOX/CUBBOX

The Organization for Economic Cooperation and Development (OECD) Pressurized Water Reactor Main Steam Line Break (MSLB) Benchmark has been calculated for all three exercises by the coupled code system ATHLET-QUABOX/CUBBOX developed by Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS). The results obtained are presented, and a detailed comparison with other solutions of the benchmark is discussed. An attempt is made to explain the differences observed in the solutions by the different modeling of physical processes in the codes. The sensitivity of results on modeling features is also investigated. In addition, the effect of different mapping schemes between fuel assemblies of the core loading and the thermal-fluid dynamics on the accuracy of three-dimensional (3-D) neutronics solutions is studied. The results for the MSLB transient are also evaluated to compare 3-D neutronics and point-kinetics solutions in view of integral and local parameters. Thus, the experiences with the coupled code system ATHLET-QUABOX/CUBBOX during the MSLB benchmark activity are summarized.