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A coincidence method for measuring Cs, K, Ra and Th decay products activity in soil, vegetation and fish samples, was applied to the six-crystal gamma-coincidence spectrometer PRIPYAT-2M. In this way, some problems appeared in simultaneous measurement of Cs, Ra and Th by NaI(Tl) detectors and the PRIPYAT-2M spectrometer were solved. The obtained results were agreeable with the HPGe spectrometer ones. [ABSTRACT FROM AUTHOR]

232Th activities in the South Adriatic Sea-water, surface sediment, mud with detritus, seagrass ( Posidonia oceanica) samples, and the mullet (Mugilidae) species Mugil cephalus, as well as soil and sand from the Montenegrin Coast, were measured using the six-crystal spectrometer PRIPYAT-2M, which has relatively high detection efficiency and a good sensitivity, and allows a short acquisition time, and measuring samples of any shape, without preliminary preparation and calibration measurements for different sample geometries. An average 232Th activity concentration in surface soil layer is found to be 40.33 Bq kg−1, while in sand—4.7 Bq kg−1. The absorbed dose rate in air due to 232Th gamma radiation from surface soil layer ranged from 11.76 to 63.39 nGy h−1, with a mean of 24.06 nGy h−1. Corresponding average annual effective dose rate has been found to be 0.03 mSv y−1. The absorbed dose rates due to the thorium gamma radiation in air at 1 m above sand surface on the Montenegrin beaches have been found to be from 0.41 to 9.08 nGy h−1, while annual effective dose rates ranged from 0.0005 to 0.011 mSv y−1. 232Th activity concentration in seawater ranged from 0.06 to 0.22 Bq L−1, as in the mullet ( Mugil cephalus) whole individuals from 0.63 to 1.67 Bq kg−1. Annual intake of 232Th by human consumers of this fish species has been estimated to provide an effective dose of about 0.003 mSv y−1. [ABSTRACT FROM AUTHOR]

A coincidence method for measuring radium and thorium activity has been developed using the PRIPYAT-2M gamma-ray coincidence spectrometer, with six NaI(Tl) detectors and registration geometry close to 4π. It was tested by measuring soil samples from the Northern region of Montenegro, as well as vegetation samples from the same region. The results showed a good agreement with ones obtained by the HPGe spectrometer. [ABSTRACT FROM AUTHOR]