Development of improved calibration methods and packages is basic to improving the application of gamma spectrometry in environmental radioactivity and radiotracer studies, and to improving comparability of results obtained from different radioanalytical laboratories around the world. The proposed CRP will assist Member State laboratories through development of analytical methodologies and software. Typically, calibrations are carried out using either of two broad approaches: the use of specially prepared standards or by computational means. The computational approach has considerable advantages, especially in terms of the costs which otherwise arise in standard preparation, but there are difficulties which will generally lead to a greater uncertainty in the final calculated efficiencies. Through the CRP the various approaches to calibration will be developed in a complementary way, with careful attention to intercomparability and validation by means of interlaboratory comparison exercises. It is expected that new methods, procedures and software tools of general use to IAEA Member State laboratories will be developed to help laboratories to optimize their detector setup and calibration systems, and to calibrate their systems once set up. The results will be distributed to all countries having an interest in application of gamma spectrometry for environmental radioactivity studies.
The CRP overall objective is to assist Member States to co-ordinate the development of validated calibration methods relying on combined experimental and modelling approaches and to establish traceability of results through comprehensive quantification of measurement uncertainties associated with low-level gamma-ray spectrometric analysis of environmental samples.
To compile and validate software tools, detailed procedures and datasets for calibration of general use to the IAEA Member States laboratories.
To develop improved calibration and efficiency determination methods for widely used types of HPGe detectors, using classical, semi-empirical and computational approaches.
To develop methods to validate and improve the inter-comparability of results obtained with different calibration approaches.
Methods to validate and improve the inter-comparability of results obtained with different calibration approaches.
New and improved calibration and efficiency determination methods for widely used types of HPGe detectors, using classical, semi-empirical and computational approaches.
Software tools and detailed procedures for calibration of general use to the IAEA Member States laboratories.
Thanks to the close collaboration of CRP participants, 10 peer-reviewed papers were published in scientific journals and computer codes used for advanced gamma spectrometry modelling were benchmarked, improving the understanding of the technical basis of data comparability and reliability. Important metrological aspects were addressed for decay data used, uncertainty budget, reporting of measurement results, including for challenging low-energy, low-activity radionuclides and decay series radionuclides. The CRP helped harmonise the approaches to gamma spectrometric analyses to environmental samples among the participating institutes and further through dissemination in conferences, peer-reviewed scientific papers, 2 MSc theses and a series of workshops and training courses delivered over the years to the ALMERA network and in the framework of regional and interregional TC projects.
The reliability and inter-comparability of environmental radioactivity data is essential in both routine and emergency situations, particularly in transboundary contamination events and for networks of laboratories, such as the IAEA's worldwide network ALMERA and national and regional environmental radioactivity monitoring networks. Gamma-ray spectrometry is a common technique, however to obtain reliable analytical results for environmental samples advanced knowledge of gamma-ray spectrometry is required. This CRP has carried out a comprehensive analysis of all the factors that can impact the quality of gamma-ray spectrometric analyses and has proposed approaches to address these.