Ceramic targets containing actinides can be bombarded with neutrons to induce transmutation reactions to remove the most difficult long-lived species. These can consist of actinide-containing solid solutions such as (Am,Zr)N, (Am,Y)N, (Zr,Cm)O 2, (Zr,Cm,Am)O 2, (Zr,Am,Y)O 2 or just actinide phases such as AmO 2, NpO 2, NpN, AmN mixed with some inert phases such as MgO, MgAl 2 O 4, (Zr,Y)O 2, TiN and ZrN. The role of non-radioactive inert phases is mainly to provide stable mechanical behaviour to the target under neutron irradiation.