[en] Much recent work on semiconductors has shown that diffusion and related processes can be vastly enhanced by the presence of free carriers (i.e. electrons and holes). In some cases quite different mechanisms take over. This note discusses two possible effects of ionisation in waste-disposal glasses, namely (1) the enhanced motion of alkalis by changes of charge state and (2) enhanced segregation through ionisation-induced electric fields near surfaces and interfaces. Both appear to be unimportant for the activity levels expected for HARVEST glasses. (author)