U.S. Department of Energy

Pacific Northwest National Laboratory

Fundamental understanding of nucleation processes to assess solution stability and phase growth and genesis

Please join us on Thursday, December 10, 2015, from Noon to 1 p.m. in the RPL Plutomium Conference Room, as the NPSI welcomes featured speaker Dr. Gregg Lumetta at the NPSI Monthly Seminar Series. Dr. Lumetta, NPSI PI, will be presenting on his project Fundamental Understanding of Nucleation Processes to Assess Solution Stability and Phase Growth and Genesis.

Research Team: Edgar Buck, Jim De Yoreo, Shawn Kathmann, Zheming Wang

Thursday, December 10, 2015
Dr. Gregg Lumetta
NPSI Project Manager
PNNL
In this project, nucleation and crystal growth of three chemical systems of importance to nuclear processing technology will be probed in depth at a fundamental level. The systems to be investigated are trisodium phosphate, plutonium(III) oxalate, and plutonium(IV) oxalate. The trisodium phosphate system is important with respect to processing of Hanford tank wastes, while the two plutonium oxalate systems are important with respect to nuclear forensics. The specific goals of this project are to develop a fundamental understanding of nucleation and crystal growth phenomena associated with precipitation of plutonium(III) oxalate, plutonium(IV) oxalate, and Na3PO4*12H2O, including (1) determining the mechanism and pathways to plutonium oxalate and Na3PO4*12H2O homogeneous nucleation, (2) determining the mechanism and pathways to heterogeneous nucleation of Na3PO4*12H2O, and (3) determining the interfacial energies and kinetic barriers that control Na3PO4*12H2O nucleation on process-relevant construction materials (both treated and untreated with coatings). We will exploit this fundamental knowledge to (1) develop a predictive capability for linking processing history to the physical properties of plutonium oxide materials by providing the molecular-based parameters to phase field modeling and other up-scaling frameworks, and (2) improve tank waste processing efficiency by developing more efficient strategies for avoiding precipitation of Na3PO4*12H2O.
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