PNNL

Abstract

Chapter 14 for the 2nd edition of the Handbook of Radioactivity Analysis. The techniques and examples described in this chapter demonstrate that modern fluidic techniques and instrumentation can be used to develop automated radiochemical separation workstations. In many applications, these can be mechanically simple and key parameters can be controlled from software. If desired, many of the fluidic components and solution can be located remotely from the radioactive samples and other hot sample processing zones. There are many issues to address in developing automated radiochemical separation that perform reliably time after time in unattended operation. These are associated primarily with the separation and analytical chemistry aspects of the process. The relevant issues include the selectivity of the separation, decontamination factors, matrix effects, and recoveries from the separation column. In addition, flow rate effects, column lifetimes, carryover from one sample to another, and sample throughput must be considered. Nevertheless, successful approaches for addressing these issues have been developed. Radiochemical analysis is required not only for processing nuclear waste samples in the laboratory, but also for at-site or in situ applications. Monitors for nuclear waste processing operations represent an at-site application where continuous unattended monitoring is required to assure effective process radiochemical separations that produce waste streams that qualify for conversion to stable waste forms. Radionuclide sensors for water monitoring and long term stewardship represent an application where at-site or in situ measurements will be most effective. Automated radiochemical analyzers and sensors have been developed that demonstrate that radiochemical analysis beyond the analytical laboratory is both possible and practical.