The Role of Reference Materials and Certified Test Samples in the Quality Control of Measurements in Nuclear Safeguards

Measurements in the nuclear field are generally carried out with great competence, which is understandable given the importance for fission material control in Safeguards. The measurements are done for the purpose of controlling the material throughput, for instance in reprocessing plants for safety and for economic reasons, but also for Safeguards declarations, where the results can be compared with those from independent Safeguards authorities. In both these applications, measurements are pursued which yield values which are consistent from the point of view of the process, or which minimise differences with regard to the results of measurements made by Safeguards authorities (operatorinspector differences). Given these circumstances, what role does the pursuit of ‘real’ values play in Safeguards?,Do we need ‘true’ values at all, or can we continue by minimising differences?