Validation of the Ants-TRACE code system with VVER-1000 coolant transient benchmarks

The objective of this paper is to start the validation of the coupled code system of the nodal neutronics solver Ants and the system code TRACE. The process consists of two exercises of well-known VVER-1000 coolant transient benchmarks: a core-vessel simulation of a main steam line break transient of the V1000CT-2 benchmark and a full plant simulation of a main coolant pump trip of the Kalinin-3 benchmark. The Ants-TRACE results are compared against other code solutions in the V1000CT-2 benchmark and measurement data in the Kalinin-3 benchmark. The results show good agreement in both benchmarks, with the deviations ranging mostly within the measurement error or the range of deviations of other published solutions. The results confirm the correct implementation of the coupling and successful modeling of relevant phenomena in coolant transient events in a VVER-1000 reactor.