Application of Various Methods for Estimating the Dose Rate of External Radiation in Forest Biogeocenoses

Based on experimental data on the distribution of 134Cs and 137Cs in the vertical profile of forest soils, retrospective calculations of the dose rate of external pine irradiation were performed using engineering methods for infinitely extended sources of finite thickness and dose conversion coefficients recommended by the ICRP. The range of the calculated dose rate of external irradiation using engineering methods is in satisfactory agreement with the results of measurements performed using a g-radiation dosimeter. At the same time, up to 95% of the radiation dose rate is formed due to the radiation of radionuclides located in the forest floor and the upper 2 cm layer of the mineral part of the soil. The radiation doses calculated by engineering methods and measured by a dosimeter are 2–3 times higher compared to those estimated on the basis of the KDP for a volumetric radiation source.