Exploratory Pu(III) Oxalate/Pu(IV) Oxide Morphology Studies

Technical Report · Wed Aug 01 00:00:00 EDT 2018

DOI:https://doi.org/10.2172/1466156· OSTI ID:1466156

Torres, Richard A. ^[1]; Chung, Brandon W. ^[1]; Lan, Pui C. ^[1]; Roberts, David J. ^[1]

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1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Exploratory experiments were performed to see if morphological information (particle- size/habit) about PuO₂ might give useful information about growth conditions for its oxalate precursor. We performed experiments with trivalent Pu and its analogue, trivalent cerium (Ce). Movies of the Ce oxalate experiments showed that solution turbidities can be a useful monitor for the precipitation kinetics. It was clear that when mixing was too slow to keep up with oxalic acid addition, precipitates formed locally, and partially redissolved when oxalic addition was complete. The Ce oxalate and oxide particle-sizes determined in liquid slurries by traditional light-scattering instrumentation agreed in general with those found by SEM imaging. The Ce oxalate size distributions depended on the synthesis conditions, but it was not monotonic in the progression from best- to worst-mixed. Uniformity, as measured by the FWHM (full width at half maximum) of the distributions, varied by a factor of two or more. Because the distributions and FWHMs did not change monotonically as synthesis conditions changed from best- to worstmixed, the utility of the size distributions for Ce as a diagnostic is doubtful.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: AC52-07NA27344
• OSTI ID: 1466156
• Report Number(s): LLNL-TR-756199; 943241
• Country of Publication: United States
• Language: English