University Scientists Are Developing a Map of Radioactive Contamination of Ivankiv district of Kyiv region

     NULES of Ukraine participates in the project “Health and environmental programs in the Chernobyl exclusion zone: development, training and coordination of medical and sanitation projects”. The Ukrainian Research Institute of Agricultural Radiology of NULES of Ukraine is responsible for the development of detailed maps of radioactive contamination of Ivankiv district. Research works are carried out in accordance with the agreement between the Ukrainian Scientific and Technological Centre, Research Centre for Radiation Medicine of the National Academy of Medical Sciences of Ukraine and the National University of Life and Environmental Sciences of Ukraine.

     University scientists are creating maps of radioactive contamination using GIS technologies and various information resources. In order to complete this project, the researchers developed a methodology for performing field works based on both national and international standards (IS0 18589-2, 18589-3 IS0, IS0 18589-5). The spring-summer period was dedicated to extensive experimental studies, including measurement of ambient equivalent dose of photon ion radiation in Ivankiv district on a grid of 1x1 km (about 3200 measurements), soil sampling on a grid of 3x3 km (about 550 samples), determination of radionuclides (137Cs, 90Sr, 40K) in university laboratories and analysis of the received data. The research in settlements is more detailed; the grid for determination of ambient equivalent dose of photon ion radiation is 0,3X0,3 km, and the grid for soil sampling is 1x1 km.

A working map of Ivankiv district with the coordinates of measurement points of ambient equivalent dose of photon ion radiation (green dots) and soil sampling (red dots)

Fragment of a hybrid map with reference points that were used in GPS navigation under field conditions
 

Creating maps of radiation contamination is extremely difficult. The main attention was focused on map data that allowed to plan roads to places distant from major roads (forest clearings, field roads, fords, etc.).

     Before the fieldwork, each dosimeter was checked for zero background. Measurements were made over the surface of a reservoir, where the contribution of gamma radiation and natural radionuclides is negligible due to the shielding water, and the dosimeter indicators are almost completely determined by the amount of its own background and response to cosmic radiation.

Measurement of zero background of the dosimeters on the ice pond

     The researchers studied the soil by sampling each reference point to determine the level of radioactive contamination in the area. The results were based on 5 single injections of a drill with a step of 3-5 meters and depth of 20 cm. This ensured completeness and reliability of sampled soil.
Currently, the fieldwork is almost completed. Five hundred fifty-six soil samples were selected and ambient equivalent dose of photon ion radiation was measured in 3155 points; the laboratory tests of soil samples are being completed. Overall, the scientists made 12 field trips and overcame more than 7000 kilometers.

     The research also revealed the existence of some places outside the exclusion zone where indexes of ambient equivalent dose of photon ion radiation exceed background values three times. First of all, these are former parking areas of cars involved in the aftermath of the Chernobyl accident. These issues require additional research and tackling.

     For the third decade leading scientists and radiologists of our university are solving the problems of radioactive contamination in our country, fruitfully collaborate with their counterparts from Japan, France, Austria, Belarus, and other countries. They do hard work in a highly professional and friendly team of patriots of science. Two unique photographs taken during fieldwork expeditions in 1997 and 2014 capture attention and cause incredible sense of respect and appreciation for their hard but important work!

Svyatoslav Levchuk and Olexander Kadygrib sample the soil in 1997 during mapping of the Chernobyl exclusion zone

Svyatoslav Levchuk and Olexander Kadygrib sample the soil in 2014 during mapping of Ivankiv district