Literature Review of Puo2 Calcination Time and Temperature Data for Specific Surface Area

Technical Basis for Doe Standard 3013 Equivalency Supporting Reduced Temperature Stabilization of Oxalate-Derived Plutonium Oxide Produced by the Hb-Line Facility at Savannah River Site

“…A broader survey of the literature on the dependence of SSA on calcination temperature (Daniel, 2012) shows that SSAs in this range for HBL product would be consistent with that observed in other laboratories. Laboratory-scale PuO 2 samples produced in support of the HBL MOX feed mission (Crowder and Duffey, 2011; also have SSAs in this range.…”

Small-Scale Testing of Plutonium (Iv) Oxalate Precipitation and Calcination to Plutonium Oxide to Support the Mox Feed Mission

“…For Case 2, the software tested for effects with all of the data and with Batch 1 data excluded, since the temperatures reported for Batch 1 have higher uncertainties. 6 of PuO 2 SSA data indicated that calcination temperature and time were primary effects on SSA and that the dependence was not linear. Tables 3-16 and 3-17.…”

“…One helpful publication from Los Alamos National Laboratory 5 showed that production of PuO 2 by Pu(IV) oxalate precipitation and subsequent calcination at 650 °C for 4 hours consistently produced PuO 2 with a specific surface area of 9.77 ± 1.79 m 2 /g and moisture content of 0.22 ± 0.08 wt %. However, a literature review 6 of PuO 2 calcination studies showed a need for additional data in the temperature range of interest, 600-650 °C. In addition, the review showed that the SSA of PuO 2 changes significantly with calcination temperature in the temperature range of interest, and the lower the SSA, the less likely the PuO 2 is to absorb moisture.…”

Kinetics of the high temperature oxygen exchange reaction on 238PuO2 powder

“…Both CeO 2 and PuO 2 appear to experience a significant decrease in SSA upon heating to high temperatures (e.g., 1000 o C), which is likely caused by generic reductions in surface area and the closing of particle porosity [9, 35,36]. Since the surface mobility and surface exchange mechanisms are dependent on SSA, decreasing SSA could cause a significant change in the rate and/or mechanism to occur in subsequent runs, or it could even cause a dynamic change to occur during the exchange experiments.…”

“…Arrhenius plot obtained from PuO 2 oxygen exchange experiments showing that the rate can be influenced by up to three different mechanisms: internal chemical reaction (■), surface mobility (X), and either a pure surface exchange or a competitive surface exchange and surface mobility based mechanism • .The assignment of the internal chemical reaction was made primarily due to the four replicate runs performed at 1000 o C exhibiting reproducible results. One of the well-known properties of both CeO 2 [9] and PuO 2[35,36] powders is that exposure to high temperatures -such as 1000 o C -tends to reduce the SSA of the material. Therefore, performing the oxygen exchange reaction at 1000 o C should cause the SSA of the material to decrease during the experiment.…”