Materials identification and surveillance project item evaluation. Item: Impure mixture of plutonium oxide and uranium oxide (PUUOXBC05)

摘要

In this report Los Alamos researchers characterize properties relevant to storage of an impure mixture of plutonium oxide and uranium oxide (impure mixed oxide (MOX) that is composed of 43.8 mass % plutonium and 17.8 mass % uranium) in accordance with the department of Energy (DOE) standard DOE-STD-3013-96. This is the first sample of an impure mixture of plutonium oxide and uranium oxide to be evaluated by the materials identification and surveillance project. Methods used to characterize the mixture include mass loss-on-calcination measurements, mass loss-on-ignition (LOI) measurements, elemental analysis, plutonium and uranium isotopic analysis, particle analyses measurements, X-ray powder diffraction, thermal desorption mass spectrometry (TDMS), and surface-area analyses. LOI measurements show a steady decrease in magnitude as the calcining temperature is increased. In contrast, calcining at progressively increasing temperatures does not appear to significantly change the specific surface area of the impure MOX. The LOI value for the powder after final 950 C calcination is 0.4 mass %. Water and carbon dioxide are the major gaseous products formed at all temperatures.