Plutonium and uranium accommodation in pyrochlore oxides

Fluorite-related ceramics have attracted considerable attention as potential host materials for the immobilisation of radionuclides. Here we have used computer simulation to investigate the relative solution energies and mechanisms for Pu3+, Pu4+ and U4+ accommodation in an extensive range of A(2)B(2)O(7) pyrochlore compounds. Solution is considered from simple oxides and via co-solution mechanisms. Results are discussed in terms of their implications for actinide retention and materials fabrication.