Determination of Curie Content and 134/137Cesium Ratios by Gamma Spectroscopy of High Burnup Plutonium-Aluminum Fuel Assemblies,

Nondestructive assay of nine highly radioactive irradiated fuel assemblies was completed at the Radiochemical Engineering Cells (REC) located in the 324 Building at Pacific Northwest National Laboratory in Richland, Washington. The REC was chosen to conduct this work because of its ability to accomodate the high dose rates associated with these fuel assemblies. The four feet thick high density concrete cell walls provide more than adequate shielding. Remote handling equipment, manipulators, cutting equipment and experienced operating personnel were available and used for this project. The NDA effort was focused on obtaining total cesium contents of the fuel assemblies, and 134/137Cs ratios to confirm burnup calculations.