In 2016-2019, comparison tests of different methods for quantitative determination of the content of the technogenic radionuclide 137 Cs in soil samples were performed. Soil samples were collected from areas with high and low 137 Cs contamination in Belarus. The intercomparison was performed as a part of an ongoing Russian-Swedish-Belarusian cooperation on the assessment of radioactive contamination of the environment. Three laboratories of the regular participants in the project and three laboratories from other facilities participated in the intercomparison that was focused on the samples of cultivated soil from the Gomel region (the first stage of comparisons, 3 samples) and the Grodno region (the second stage of comparisons, 4 samples). Results on activity concentrations in the samples presented by the participants were in satisfactory agreement with each other. The maximum deviation from the average value, that had been calculated for each sample based on the individual results from all laboratories, was 14%. Stage-averaged deviations from the inter-laboratory mean did not exceed 10%. Results of the comparison tests should be taken into consideration when comparing or merging experimental data from different laboratories participating in the Russian-Swedish-Belarusian cooperation project.

After the Chernobyl accident, a certain proportion of agricultural land was withdrawn from normal use due to significant radioactive contamination. Forestry is one of the options currently under consideration to return the abandoned agricultural land to economic circulation in Russia. When using former agricultural land for forestry in radioactively contaminated areas, it is important to have an assessment of the potential radiation doses for forestry workers and the public. The aim of this study was to assess the radiological situation in a young pine forest planted and grown after the Chernobyl accident in the resettlement zone on a former arable field. A nearby old pine forest, which had grown before the Chernobyl accident, was taken for comparison. The study of the radiological situation was performed in the period 1998–2022. In the young forest, 137Cs was fairly evenly distributed in the upper 20 cm soil layer; further with depth, the activity concentration of 137Cs sharply decreased. In the old forest, the maximum activity concentration of 137Cs in the soil was in the top 0–2 cm layer. The activity concentration of 137Cs decreased with depth. In 1998, the average value of the absorbed dose rate in the air from 137Cs+134Cs was lower by a factor of 3 in the young forest compared to the old forest. The difference was associated with differences in the vertical distributions of 137Cs in the soil. Over time, the absorbed dose rate in air from 137Cs+134Cs decreased at both sites with the same effective halftime period of 21.7 year. The activity concentration of 137Cs in the biota (pine trees, edible mushrooms) in the young forest was lower by a factor of 4–30 compared to the old forest. The “forest” component of the external effective dose to adults from the 137Cs source in the young forest was lower by a factor of 3 compared to the old forest. The “forest” component of the internal effective dose from 137Cs was lower by a factor of 10 when eating edible mushrooms from the young forest compared to the old one. In general, the performed study shows that the use of radioactively contaminated abandoned arable land for forestry can be expedient and justified from a radiological point of view.

The article proposes an empirical method for constructing a universal calibration for a scintillation gamma spectrometer, which allows determining the activity and specific activity of 137Cs with an accuracy of no more than 15% in counting samples of arbitrary density and volume in cylindrical containers with a volume of 250 ml and 500 ml. To construct calibration ratios, measurements of 137Cs sample media prepared on the basis of materials of different densities (quartz sand, plastic granules and sawdust) were performed. The calibration was carried out by preparing samples from the listed materials with a volume of 50 to 250 ml in increments of 50 ml for a 250 ml container and 100-500 ml in increments of 100 ml for a 500 ml container. Along with taking into account the volume of the counting sample, its weighing was also carried out. The result of the measurements performed for each material was the ratio of the activity of the counting sample to the counting intensity in the 137Cs window, depending on the volume. The universal calibration factor is obtained by taking into account the counting rate from the mass and volume of the sample for the corresponding measuring vessel.

The paper considers a qualitatively new interpretation of the known dimensionless geometric characteristics, which acquire greater significance and make it possible to estimate the average gas content during both high-altitude and deep-water rise.

Based on the analysis of known experimental data, a generalizing geometric complex was suggested for highaltitude and deep-sea lifting. The complex made it possible to obtain empirical relationships for determining the metering characteristic of each type of transportation in the optimal mode.