New methodology for in-situ classification of radiological items with a clearance monitor system

Maintenance activities and operations of high-energy particle accelerators can lead to the collection ofradioactive equipment as well as waste materials. In order to ensure their proper classification as radioactiveor non-radioactive, one has to quantify the activities of radionuclides produced. According to the regulatoryrequirements in Switzerland, these activities need to be compared with nuclide-specific clearance limits. Inparticular, a new set of clearance limits was introduced by the Swiss authorities in January 2018, leading tomore conservative values for a number of relevant radionuclides. The present paper complements a previousone in which we developed a methodology to classify equipment with specific characteristics following a doserate measurement. For equipment that do not fulfill these characteristics, we here extend the methodology byusing a total gamma counting device. This methodology concerns the specific material compositions typicallyfound at CERN and takes into account the latest clearance limits introduced by the Swiss authorities. Also,particular considerations are given for electronic components. Their characterization is challenging due to themultiple compositions that can be found in the literature, whereas activation mechanisms are highly sensitiveto the material composition.