TPOP-II: Tritium Fueling at a Reactor Scale

As part of the International Thermonuclear Experimental Reactor (ITER) plasma fueling development program, Oak Ridge National Laboratory has fabricated a pellet injection system to test the mechanical and thermal properties of extruded tritium. This repeating single-stage, pneumatic, Tritium-Proof-of-Principle Phase II (TPOP-II) Pellet Injector has a piston-driven mechanical extruder and is designed to extrude and accelerate hydrogenic pellets sized for the ITER device. Tritium and deuterium-tritium (D-T) pellets have been produced in experiments at the Los Alamos National Laboratory Tritium Systems Test Assembly. About 38 g of tritium was used in the experiment. This paper presents results of the TPOP-II extrusion experiments. These extrusion experiments indicate that both T₂ and D-T will require higher extrusion forces than D₂ by about a factor of 2 and that the flow of the material may be characterized by static and dynamic shear strengths.