Design features of the JET vacuum enclosure for safe operation withtritium

摘要

The JET (Joint European Torus) machine is intended for eventualoperation with tritium-deuterium plasmas to produce very significantfusion reactions. Starting from the initial design concept, and thenfrom its evolution resulting from operational experience andsimultaneous theoretical studies, a consistent approach has beendeveloped for the preparations needed for safer operations with D-Tplasmas. The main machine vacuum components are inherently suitable asthey were designed for tritium operation and are physically very strong,where necessary. Ongoing experience with certain components andappendages is indicating the detailed design changes necessary.Fundamental features of all-metal construction and double containment onweak points such as bellows create designs which have built-in primarysafety. Work is in progress on detailed identification and rectificationof weaknesses in the design. Tritium compatibility assessments of allsubsystems are being undertaken as part of a safety approval program forthe use of tritium in the JET