Shielded gloveboxes are currently being constructed to facilitate dilution and disposal of many tons of excess plutonium oxide. Measuring holdup in these gloveboxes is expected to be challenging because of the limited available lines of sight through the glovebox shielding. A system of gamma-ray imagers is being developed to provide localization and quantification for holdup. The system will be mounted above the glovebox, where there is minimal shielding. Multiple imagers with overlapping coded-aperture f ields of view are employed to enable three-dimensional reconstruction. Compton reconstruction is also available to localize sources outside the coded-aperture field of view. Improved uncertainties with respect to current techniques are expected by virtue of the fixed installation, spectroscopic performance of the detectors, and use of iterative image reconstruction techniques. Measurement campaigns have been undertaken at an active glovebox at the Savannah River Site to test gamma-ray imagers in an operational environment that mimics the installation proposed for future shielded gloveboxes. Data recorded during quiescent periods in the glovebox were used to measure the buildup of material on an outlet filter and record a trend over time. The resulting images make it possible to isolate the filter from other sources and recognize compromised data. Calibration data was recorded with known sources to provide a reliable assay of the filter. This paper will present details of the measurement and analysis methods.
Year
2024
Abstract