SIStec is an in-house software development for improving the material clearance process with a clearance measurement system. Simple, intuitive handling and the approved software for measured material calibration considerably simplify operations. The use of an imaging method eliminates the need for conservative assumptions about activity distribution. This, along with complete statistical analysis according to DIN EN ISO 11929 and virtual subdivision of the measured material, allows proof of clearance readiness for a larger number of measured materials. SIStec therefore means that a larger amount of material can be returned to the recycling loop.