Around 100 grams of tritium was supplied to the JET machine during the 1997 DTE1 campaign. A significant proportion of this was retained in the machine and only released slowly over the succeeding operational and maintenance campaigns Tritium is also present though permeation and surface adsorption of materials. Means of detritiation of JET waste which could be applied within the facility are being developed. These must take into account the full waste cycle including the generation of secondary waste and the possibility of recovery for re-use of tritium. Each of the typical JET tritiated waste streams is described and the detritiation processes being developed and under consideration are discussed.