Spontaneous fragmentation of an alpha-active ceramic: a mechanism for dispersion of solid waste

Studies underway to characterize spontaneous fragmentation in 238PuO2 and to determine the mechanism(s) responsible are reported. Results reported here show that: spontaneous fragmentation of 238PuO2 generates a wide range of particle sizes, from a few mm to 1000 A or less; the phenomenon may continue with time or may saturate, depending on starting material; the magnitude of the effect is dependent on storage environment. Neither thermal stresses nor lattice damage appear to be solely responsible for fragmentation, but radiolysis of the environment could play an important role. Work is continuing in an effort to identify the controlling factors in this phenomenon