Status of the JET Active Gas Handling System and Plans for Tritium Operation

The Joint European Torus (JET) carried out the first preliminary experiment with a deuterium-tritium plasma in 1991. This utilised an on-site inventory of 0.25g. The future experimental programme for the JET machine includes two discrete phases using plasmas fuelled by deuterium and tritium. The first of these, in mid-1996, will generate around 2 × 10²⁰ neutrons and require a site inventory of a few grams of tritium. The second is proposed to take place in 1999 if an extension to the JET project from 1996 is granted. This will require a few tens of grams of tritium and will generate up to 5 × 10²¹ neutrons. The JET Active Gas Handling System has been constructed to enable tritium to be recovered from the plasma exhaust and stored for re-injection. The design also minimises tritium discharges to the environment. It is currently being commissioned to meet the above programme and has been modified to take into account a new requirement for operation over extended periods during maintenance and D-D operation with tritium contaminated plasma exhaust. Commissioning of the Active Gas Handling System consists of inactive, trace tritium (∼40TBq) and full tritium (<3g) phases. The experience and main results of inactive commissioning are presented and the status of tritium commissioning is reviewed.