Publications
Showing 42 results for Author: Kathryn M. Lawson
Sep, 2026
Journal
Reduction of Np(v) to Np(iv) using oxalic acid: rethinking decades of nuclear processing conventions
Actinide oxalate precipitation has been ubiquitous in nuclear processing since the 1950s due to its simplicity at laboratory and production scales as both a means of actinide purification and as a key intermediate solid phase towards oxide production. Historical processing information has emphasized the need to reduce actinides, including neptunium (Np), to the tetravalent…
Jul, 2026
Journal
Modern insights into the mechanisms of neptunium oxalate decomposition
Neptunium oxalate (Np(C2O4)2·6H2O) is a historically relevant solid phase used in nuclear processing as a precursor for neptunium dioxide (NpO2). Although Np oxalate has been synthesized and used for NpO2 production for decades, the thermal decomposition mechanism of this phase remains poorly understood and has not been evaluated in over 30 years. Conflicting reports in hi…
Jul, 2026
Journal
Sintering effects on NpO2 grain size and morphology: The role of precursor Np phase
Neptunium dioxide (NpO2) is a key phase in nuclear material processing as a target material for the production of plutonium-238 (238Pu) and has been historically synthesized via the calcination of a Np oxalate precursor. Alternative synthesis methods for NpO2 are now more prevalent, necessitating their study and comparison with the more common oxalate route. The purpose of…
Mar, 2026
Conference Paper
Materials Characterization Capabilities for the Plutonium-238 Supply Program
Feb, 2026
Journal
Understanding the structural and morphological effects of synthesis route on NpO2
The availability of actinide standard materials for use in nuclear safeguard applications is critical, as is thorough characterization thereof. Although accurate trace element compositions and isotopic considerations are paramount for deployment of reference standards, structural characterization is also essential towards accurately describing the chemical form and potenti…