Year
2012
Abstract
The Hybrid K-Edge Densitometer (HKED) is a high-precision assay system developed to provide the uranium and plutonium concentrations in the dissolver solutions from a reprocessing plant. The HKED technique has been used routinely for the assay of uranium and plutonium in fresh mixed oxide (MOX) and spent nuclear fuel dissolver solutions for more than 20 years. Recent changes in safeguards objectives and the evolution of the nuclear fuel cycle have resulted in an expansion of the list of actinides of interest and a need for algorithm enhancements for the HKED analysis. To support these development activities, a commercial HKED system has been installed at the Oak Ridge National Laboratory (ORNL) Radiological Engineering Development Center (REDC). The REDC at ORNL is a multipurpose Category II radiochemical processing facility providing the capability to fabricate a broad range of mixed actinide solution standards for testing and future developments of the HKED technique. Initial performance testing of the HKED system to demonstrate the measurement precision and accuracy utilizing uranium and plutonium solutions produced at the REDC has been successfully completed. A long-term study of the stability of the solutions while stored in the HKED measurement vials has been initiated to evaluate their effective working lifetime for use as quality control standards. Preliminary results for these stability measurements are presented, along with a comparison of the HKED measurements against the Destructive Analysis (DA) results.