Tritium Challenges and Plans for ITER Pellet Fueling and Disruption Mitigation Systems

ITER will use a Pellet Injection System (PIS) for supplying deuterium-tritium (D-T) fuel to the fusion plasma and a Shattered Pellet Injection (SPI) system for rapidly injecting impurities (argon or neon mixed with deuterium) as solidified pellets into the plasma for the purpose of mitigating the harmful effects of plasma disruptions as part of a Disruption Mitigation System (DMS). Both systems are being designed to handle significant amounts of tritium in the process streams and are exposed to similar environmental conditions during operation, including exposure to gamma and neutron radiation and significant magnetic fields. Multiple barriers to prevent the potential release of the tritium inventory into the environment are included in the designs. The unique environmental conditions present some challenges and are currently being addressed during the design phase.