Spatial radionuclide deposition data from the 60 km radial area around the Chernobyl nuclear power plant, 1987

A radial network of sample points every 10° (from 10° tо 360° clockwise) at distances of 5, 6, 7, 8.3, 10, 12, 14.7, 17, 20, 25, 30, 37.5, 45, 52.5 and 60 km from the Chernobyl nuclear power plant (resulting in 540 sample points) was established in April-May 1987. Geo-referencing of sampling points was performed using maps and topography.
Samples were collected from all sampling points except those located in swamps, rivers and lakes; in total 489 of the 540 selected points were sampled. Soils were sampled using a corer with a diameter of 14 cm and depth of 5 cm. Equivalent dose rate was measured at a height of 1 m above ground at each sampling point. At each sampling site, soil samples were collected from five points using an envelope sampling design (with approximately 5-10 m between sampling points). Each soil sample was retained intact within the corer during transportation to maintain sample integrity and prevent mixing.
One soil sample from each sampling site was analysed in a 1 litre Marinelli container by the UIAR laboratory using a high-purity germanium detector (GEM-30185, ORTEC, USA) and a multichannel analyser “ADCAM-300” (ORTEC, USA) to determine the concentrations of gamma-emitting radionuclides (95Zr+95Nd, 106Ru, 134,137Cs, 144Ce). A 100 g aliquot of soil was leached using 1M NH4Ac solution at pH 7 (solid: liquid ratio 1:5). The soil-extractant solution was shaken for 1 hour and then left for 1 day at room temperature. The solution was then filtered through medium ashless filter papers (3-5 µm) and put into a suitable container for analysis on a Ge-detector to determine the fraction of exchangeable 134,137Cs.
Radionuclide activity concentrations in soils were used to calculate the density of soil contamination (1 Ci km-2= 37 kBq m-2) taking into account the area sampled (0.015 m2). Measured activity concentrations were reported at the 68% confidence level (i.e. one standard deviation). It has been estimated that when one discrete soil sample (area of sampling 0.015 m2) is used to estimate a value of average contamination density of the sampling site (i.e. the area over which the five cores were collected) the uncertainty may be up to 50%.

This dataset is included in the following collections

TRansfer - Exposure - Effects (TREE) Integrating the science needed to underpin radioactivity assessments for humans and wildlife