Year
2004
Abstract
The need to comply with nuclear safety limits is of particular concern when dismantling plant equipment that may have handled large quantities of plutonium. Often such gloveboxes contain residual plutonium left behind after Post Operations Clean Out (POCO) but these quantities and their distribution are seldom known. Consequently non-destructive assay equipment has been developed to measure the plutonium residues and distribution in the plant items before dismantling operations are initiated. This equipment, known as the Decommissioning In-Situ Plutonium Inventory Monitor (DISPIM®) provides an in-situ non destructive assay of plutonium within plant items or gloveboxes. The DISPIM has been used for the measurement of almost 200 gloveboxes to support decommissioning activities at BNFL’s Sellafield reprocessing plant in the UK. The latest development of DISPIM has been to incorporate novel timestamping electronics, bringing benefits of scalability, and flexibility to the system. Advanced 3-dimensional imaging algorithmsi permit the identification of multiple source locations within the measurement volume. The flexible deployment and analysis provided by DISPIM permits its use for measurement of plutonium within irregularly shaped items permitting mass and distribution (location) of plutonium to be determined. There are obvious parallels with the requirements of homeland security, providing a rapid measurement that could locate and quantify plutonium within vehicles, shipping containers, or parcels for example.