In-situ gamma spectrometry in environmental monitoring

Full text: In-situ gamma spectrometry (using scintillation or semiconductor detection systems) can be effectively used for the monitoring and determination of the natural as well as man-made radionuclides concentrations and corresponding photon fields in the environment and workplaces. It find applications in nuclear facilities (NPP, spent fuel storages) operational and emergency monitoring, monitoring of waste storages and uranium industry, radioactive contamination measurements and mapping, environmental, radiohygienic and radiation safety studies, etc. Ground as well as airborne monitoring arrangement is possible. Method of data processing and interpretation, experimental techniques calibration and verification and examples of application are discussed. (i) Data processing methods: Interpretation of gamma spectrometry data in terms of photon field characteristics (dosimetry quantities) or radionuclides concentrations needs spectra deconvolution based on detection system response function or efficiency calibration knowledge. Usage of method based on the Monte Carlo simulation of the photon field angular energy distributions and detection system response/response matrix calculation is described and discussed. Full spectra analysis/deconvolution for dosimetric quantities calculation (ground monitoring) and method based on the peak analysis for airborne monitoring and semiconductor spectrometry are discussed. (ii) Applications: Verification of data processing method by calibration and intercomparison measurement is shown and examples of applications in the field of environmental monitoring and working places measurements are presented. Advantages (namely spectral information that enable to identify and calculate contributions from individual radionuclides) and limitations of described in-situ gamma spectrometry methods are discussed. Next developments of experimental techniques, data processing methods and interpretation of results are also suggested. (author)