Prospects of returning radioactively contaminated lands in the northern part of Ukraine to economic use

About tens thousands hectares of agricultural land in the norther part of Ukraine cannot be used for agricultural production under the Law 'On the Legal Regime of the Territory Affected by Radioactive Contamination as a Result of the Chornobyl Disaster' since 1986 only in Zhytomyr Oblast. Additionally, due to Russia's aggressive military actions, large areas of Ukraine (currently near 800 thousands ha) are unable to carry out agricultural work. It may take over minimum ten years to clear the territories of mines. In these circumstances, revision of the actual contamination levels of lands may help to increase the share of agricultural lands in Ukraine. But before the economic use of these lands, it is essential to conduct a survey to determine the level of soil contamination with radionuclides and assess the radiological situation. This data will form the basis to decide whether the previously contaminated lands can be returned to economic use.

We conducted the radiological surveys, where the radiation background indicators were measured in 2023 in Narodychi and Vyazivka using modern devices that allow automatic registration of routes with GPS reference and marking of gamma background parameters. We recorded from 200 to 600 points on each field to build maps of the spatial distribution of soil radioactive contamination. The Narodychi community in Zhytomyr Oblast provided 30 field plots marked as 'radioactive land' in the State Land Cadastre of Ukraine. These plots include 23 agricultural lands covering an area of over 1400 hectares and 7 floodplain meadows of the Uzh and Zherev rivers covering 1200 hectares. The levels of radioactive contamination in the soil were determine on the agricultural lands, specifically with regards to ¹³⁷Cs, ⁹⁰Sr, and partially ^238-240Pu isotopes. The maps were constructed to determine the density of radioactive contamination of soil in each field based on the obtained results.

We concluded, that the density of ¹³⁷Cs, ⁹⁰Sr and ^238-240Pu contamination in the agricultural lands around the settlements of Narodychi and Vyazivka did not exceed the lower limit of the criteria for their classification as an unconditional (mandatory) resettlement zone. Specifically, cesium, strontium and plutonium isotopes did not exceed 555 kBq/m², 111 kBq/m² and 3.7 kBq/m², respectively. While the criteria for assignment to the guaranteed voluntary resettlement zone are limited to cesium isotopes from 185 to 555 kBq/m², strontium from 5.55 to 111 kBq/m², or plutonium from 0.37 to 3.7 kBq/m² (according to Article 2 of the Law of Ukraine "On the Legal Regime of the Territory Affected by Radioactive Contamination as a Result of the Chornobyl Disaster"). Accordingly, all surveyed land should lose its status as 'radioactive land' and can be returned to economic use.

We acknowledge the National Research Foundation of Ukraine for the financial support of this research (Project number 2022.01/0188).