CONTRIBUTION OF THERMAL-HYDRAULICS SIMULATION TO CRITICALITY ANALYSIS OF A DEBRIS BED NUMERICAL MOCK-UP

In this work, we evaluate the impact of simulating thermal-hydraulics feedback in criticality risk assessment a benchmark configuration corresponding to simplified debris bed. We have recently discussed coupling multi-phase code MC3D with reactivity evaluation scheme based on multi-point kinetics, which paves way towards system behavior terms energy release. analyze as function state system. For our investigation, considered cylindrical region and assumed that fuel particles mixture consist spheres small diameter. The power has been adjusted be representative nuclear decay heat. most examined configurations, maximum lies below zero, shows occurrence event is likely excluded, thanks contribution heat fuel.