CX-270382: Experimental Determination of Helium/Air Mixing in Helium Cooled Reactor –University of Michigan

The University of Michigan, in collaboration with the University of Idaho, proposes to examine the mixing and venting of helium and reactor-cavity air after a loss-of-forced-cooling accident due to a break in the primary coolant pressure boundary via three investigations. 1. Near-field experimental examination of He/Air mixing behavior and air ingress in the event of a break associated with the cross vessel. 2. Far-field experimental examination of He/Air mixing behavior within the cavity between the reactor vessel and the power conversion vessel and the containment in the event of a break associated with the cross vessel. 3. Computational Fluid Dynamic (CFD) modeling of He/Air mixing behavior to inform or identify placement of instrumentation for experimental work. To address gaps in experimental and modeling work, experimental scaled reactor system mockups (test cells) shall be built and installed. Mixing and venting of helium and reactor-cavity air in the Reactor Pressure Vessel (RPV) volume and the corresponding cavity will be modeled.