This paper aims to evaluate the performance of gamma-ray spectrometry in the Institute of Applied Nuclear Physics (IANP), Albania using Proficiency Tests (PTs). Participation in different proficiency tests is an essential tool for the improvement and testing of High Purity Germanium detector (HPGe) performance. The gamma - ray spectrometry laboratory in the last years has participated in different worldwide open proficiency tests organized by International Atomic Energy Agency (IAEA) with satisfactory results. For this paper, we selected the proficiency test organized by the IAEA in 2020 due to the analytical challenge of recognizing radioactive disequilibrium and applying appropriate decay corrections, especially for ingrowing radionuclides of broken natural decay series. The PTs of gamma-ray spectrometry measurements are carried out to improve the laboratory’s ability to measure the radioactivity in the environment and foodstuffs at typical routine levels. The activity concentration of the test samples and the evaluation of the associated uncertainties are the main requirements of the test results. This PT was focused on the determination of anthropogenic and natural radionuclides in water, fish, and simulated aerosol filter samples. For this proficiency test, the Laboratory Sourceless Calibration Software (LabSOCS) is used for simulating the absolute efficiency curve. This paper presents the results and discusses the quality of the gamma spectrometry measurements performed in the IANP. The overall performance evaluation showed that 100 % of all reported results have been acceptable. Thus, the gamma-ray spectrometry using an HPGe detector showed high performance in the determination of anthropogenic and natural radionuclides in water, fish and simulated aerosol filter samples.

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