Gamma-ray Spectrometry Measurement of Concrete Samples from Nuclear Decommissioning Facilities – Validation of the LabSOCS™ Efficiency Calibration at Low Energies

Proper characterization and segregation of materials arising during decommissioning operations are very important factors in waste minimization. Characterization helps develop a complete understanding of the radiological characteristics of these materials in order to enable them to be segregated and to be sent for selected disposal. A number of techniques for measuring the radioactivity of materials generated in decommissioning operations are available. Failure in control procedures at any step can cause important consequences, not only in follow-up steps, but, in some cases, may result in generating waste packages which are not compliant with the waste acceptance criteria for long term storage or disposal. In this work we propose three different methodologies for the adjustment of the samples attenuation coefficients in order to validate the efficiency calibration curves generated by Mirion LabSOCS™ (Laboratory Sourceless Calibration Software). The three methodologies can be applied in the case where it is required to perform γ-rays spectrometry measurements at energies below 200 keV, on concrete samples of unknown chemical composition.