Scaling analysis for the high temperature Gas Reactor Test Section (GRTS)

This paper presents an overview of a scaling analysis for a reduced scale Gas Reactor Test Section (GRTS) capable of modeling a variety of important phenomena in a Very High Temperature Gas Reactor (VHTR). This research effort is being conducted at Oregon State University in support of an Idaho National Laboratory (INL) Lab Directed Research and Development (LDRD) project titled, Developing Core Flow Analysis Methods for the VHTR and GFR Designs. The INL point design for a prismatic core VHTR was selected for this scaling analysis, although the project maintains its secondary objective of co-generating Gas-Cooled Fast Reactor GFR-relevant thermal hydraulics data. The specific goal of the scaling analysis was to support the design of a test facility that can be used to produce benchmark data for Depressurized Conduction Cool-down (DCC) LOCA conditions. The scaling analysis determined that the GRTS will be capable of simulating core conduction and radiation heat transfer, vessel radiation heat transfer, core temperature profiles, air-ingress by lock-exchange, air-ingress by molecular diffusion, and single-phase air natural circulation. This paper shall focus on two aspects of the GRTS scaling analysis; air-ingress scaling analysis and scaling of the core heat transfer behavior for a DCC event.