Development of a magnetic resonance sensor for on-line monitoring of 99Tc and 23Na in tank waste cleanup processes: Final report and implementation plan

In response to US Department of Energy (DOE) requirements for advanced cross-cutting technologies, Argonne National Laboratory is developing an on-line sensor system for the real-time monitoring of 99Tc and 23Na in various locations throughout radioactive-waste processing facilities. Based on nuclear magnetic resonance spectroscopy, the highly automated sensor system can provide near-real-time response with minimal sampling. The technology, in the form of a flow-through nuclear-magnetic-resonance-based on-line process sensing and control system, can rapidly monitor 99Tc speciation and concentration (from 0.1 molar to 10 micro molar) in the feedstocks and eluents of radioactive-waste treatment processes. The system is nonintrusive, capable of withstanding harsh plant environments, and reasonably immune to contaminants. Furthermore, the system is capable of operating over large variations in pH, conductivity, and salinity. This document describes design parameters, results from sensitivity studies, and initial results obtained from oxidation-reduction studies that were conducted on technetium standards and waste specimens obtained from DOE's Hanford site. A cursory investigation of the system's capabilities to monitor 23Na at high concentrations are also reported, as are descriptions of site requirements, implementation recommendations, and testing techniques