Reaction of plutonium dioxide with water: formation and properties of PuO(2+x)
Results show that PuO(2+x), a high-composition (x </= 0.27) phase containing Pu(VI), is the stable binary oxide in air. This nonstoichiometric oxide forms by reaction of dioxide with water and by water-catalyzed reaction of dioxide with oxygen. The PuO(2) + H(2)O reaction rate is 0.27 nanomoles per meter squared per hour at 25 degrees C; the activation energy at 25 degrees to 350 degrees C is 39 kilojoules per mole. Slow kinetics and a low lattice parameter-composition dependence for fluorite-related PuO(2+x) are consistent with a failure to observe the phase in earlier studies. Perplexing aspects of plutonium oxide chemistry can now be explained.
Haschke
JM
11003 Willow Bend Drive, Waco, TX 76712, USA. Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
Allen
TH
Morales
LA