We are frequently asked about the reliability of the results we obtain using HGRS on decommissioning nuclear sites. How is it possible that a 100 mg sample of concrete collected using ViridiScope in just 120 s and counted for only ten minutes can be as dependable as a 50 g sample sent to an off-site laboratory. We don’t claim to get down to the very low detection limits required for clearance, but we can detect and quantify activity in ILW, LLW and VLLW, down to 10 Bq/g for Cs-137 and...