Thermal plutonium recycling has been demonstrated by Kraftwerk Union AG/Alkem on a large scale since 1972 in power plants at Obrigheim and Gundremmingen, Federal Republic of Germany (FRG). An improved mixed-oxide (MOX) fuel fabrication technology has been available since 1981. Such improved MOX fuel is currently being used at Obrigheim, Neckarwestheim, Unterweser, Grafenrheinfeld, FRG, and Beznau 2, Switzerland. The MOX fuel assemblies currently inserted exhibit an operating performance that is comparable to that of uranium fuel assemblies. Postirradiation investigations on MOX fuel show high mechanical stability, low shrinkage and swelling, and good behavior during power transients. On the basis of this experience, large-scale use of MOX fuel is technically feasible.