Developments in radiography and tomography of waste containers at the Idaho National Engineering Laboratory

oThe Idaho National Engineering Laboratory (INEL) has been inspecting containers (boxes and drums) of nuclear waste materials using real-time radiography (RTR) for the past ten years. Requirements governing characterization of containerized waste for short-term storage, treatment, transportation, and disposal have become more stringent. These new requirements, and the need to reduce inspection times to increase throughput, necessitate improvements in the information obtained by radiographic methods. RTR provides a qualitative view of container contents, whereas quantitative information is often required. Two projects at the INEL are converting the present qualitative radiographic inspection to the more quantitative digital radiography (DR) and computed tomography (CT) methods, while retaining the RTR function. The first project is modifying, the RTR hardware at the Radioactive Waste Management Complex (RWMC) to allow rapid processing of analog RTR images. The digital RTR (DRTR) system described here can digitize, process, and redisplay RTR images at video frame rates allowing for real-time image improvement features such as edge detection, contrast enhancement, frame subtraction, frame averaging, and a variety of digital filtering options. The second project is developing a complete radiographic and tomographic capability that allows for greater sophistication in data acquisition and processing as the operator and/or requirements demand. Themore » approach involves modification of an industrial CT scanner with the capability to acquire radiographic and tomographic data in several modes, including conventional RTR, DR, and CT with a linear detector for high spatial resolution, and DR and CT with an area detector for high throughput. Improvements in image quality and quantitative digital radiographic capabilities of the DRTR system are shown. Status and plans for the modified CT scanner (presently under development) are also presented.« less