Tritium inventory in the first wall of JET

At the start of the shutdown following the DTE1 experiment at JET there remained 6.2 g of tritium in the JET vacuum vessel. An attempt has been made to establish the location of this tritium by measurement of components taken from the vessel. 2.0 g of tritium was recovered by out-gassing and 1.5 g was originally estimated for the flakes/deposits from measurement of collected flakes. Measurements on tiles removed from the vessel indicate that all the vessel tiles contain less tritium than expected at #approx# 0.1 g. Some uncertainty exists in the location of the remaining tritium. Further investigation has shown that a significant quantity of flakes (more than originally estimated) exists in the sub-divertor region. It is believed that the discrepancy between the tritium missing and that accounted for is present in the flakes in the sub-divertor region. However, until this material can be collected and quantified other possible sources cannot be excluded. The reasons for the formation of the flakes/deposits are discussed. (author)SIGLEAvailable from British Library Document Supply Centre-DSC:4672.262(99/60) / BLDSC - British Library Document Supply CentreGBUnited Kingdo