In-vessel thermal-hydraulic analysis

This paper presents some recent results obtained from the COMMIX-1A code for the EBR-II reactor transient No. 10, Phase 2. Both the reactor vessel and the neutron shield assembly and assembly arrangement in the reactor core are shown. The computational grid system used in COMMIX-1A is presented. Reactor flow and power transients are shown. Velocity and temperature distributions at steady state and t (time) = 60 sec are included. Finally, a comparison between the calculated results from COMMIX-1A and experimental measurements are presented for outlet temperatures for driver subassembly of XX08, top-of-core temperature for driver subassembly of XX08, and low-pressure plenum mass flow respectively.