Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)
Ground gamma-ray spectrometry determination of 137Cs in soils of the Jeseníky region and verificationof its reliability
Abstract
The Jeseníky region in northern Moravia, Czech Republic, was a relatively highly contaminated area by nuclear fallout from Chernobyl accident in 1986, attaining locally 137Cs surface activity of 100 kBq/m2. Ground gamma-ray spectrometry with portable spectrometers GS-256, GR-320 and GR-130 was applied at the locality Klepáčov, Jeseníky region, in 2002. The objectives of field experiments were the estimates of 137Cs in soil 16 years after nuclear fallout contamination, and determination of precision and accuracy of 137CS field assays through comparison measurement by independently calibrated Instruments and differ-ent data processing approaches. Very low concentration of natural radionuclides K, U and Th in amphibolites and gneisses of the Desná dome at the locality (Tab. 1) contrasted with a high 18-46 kBq/m2 surface activity of 137Cs (Tab. 2), prevailing by its dose rate over natural gamma radiation. Very good correspondence of I37Cs independent assays, having a mean relative difference of 6 per cent (Tab. 2), proved the suitability of field scintillation gamma-ray spectrometry for nuclear falout estimates.
