Study on optimization of actinide oxalate precipitation process in a vortex flow reactor

ABSTRACT

Oxalate precipitation process is globally accepted and is the current choice for conversion of actinide nitrates to their oxides. A vortex flow reactor with magnetic stirrer is found to be a better option for a hassle-free operation of batch as well continuous actinide reconversion process. Utilization of magnetic stirrer as an alternate for the conventional mechanical stirrer eliminates corrosion-related issues as none of the metal parts are in contact with nitric acid as well as oxalic acid solution. Moreover, this alternative system ensures a maintenance-free process. Optimization of various process conditions in a vortex reactor was accomplished using cerium nitrate as a surrogate for actinide nitrate and the results obtained were compared with that of pitched blade mechanical stirrer. About 40 L of thorium nitrate solution was successfully precipitated by the optimized procedure in a vortex reactor.

Keywords:

• Vortex flow reactor
• actinide oxalate
• precipitation
• PUREX

Acknowledgements

The worthy contributions extended by Smt. Umadevi of SNRF during the equipment design are gratefully acknowledged. We are thankful to staff members of PSDD and FRD Laboratories of BARC for their support in experiments and sample analyses.