Large agricultural land surfaces in theChernobyl arealocated in the northern region of Ukraine, could be potentially rehabilitated for use in agricultural activitiesafter being sure during a recent course investigation conducted in collaboration between researchers from the University of Portsmouth and the Ukrainian Institute of Agricultural Radiology. A standardized protocol for the quantification of the density of contamination by radionuclides in agricultural land currently excluded From the economic use following the 1986 disaster. Although the proposed methodology allows an accurate assessment of the suitability of soils for agricultural production, the revocation of regulatory restrictions requires the experimental validation of the ability to cultivate plant species conforming to the rigorous food radiological safety limits currently applied in Ukraine.
Zoning of contaminated land and reduction of radioactivity to Chernobyl
Following the nuclear accident of the April 26, 1986, The Soviet authorities ordered, with a delay of a few days, the full evacuation of the town of Pripjatthe urban center closest to the Chernobyl power plant. Currently abandoned, the city falls within the so -called “Exclusion area“(or area 1), an area of approx 4200 km2 surrounding the nuclear site, completely without human settlements. Around this area are articulated two areas at a reduced risk:
- “Compulsory resetting area“(or area 2), consisting of land in which human residence and any agricultural or economic activity is prohibited;
- “Guaranteed voluntary resettment area“(or area 3), where soils are contaminated by radionuclides but can be used for agricultural activities, after applying appropriate radiological mitigation measures
The criteria for zoning contaminated land have been formally established in 1991, based on the density of contamination by Radionuclidi, including Cesio-137 (137CS) and the Strike-90 (90SR), which represent the main sources of concern outside of zone 1. Since then it was not however, no reclassification of soils has been carried out, despite a progressive reduction Both of the levels of radioactivity and of the mobility of the isotopes of Cesio in the ground. In Ukraine, the modification of the restrictions applied to the surfaces of the contaminated land can take place exclusively through a legislative aimed at reviewing the subdivision procedure of the areas. Otherwise, in Russia and Belarus, the areas subject to limitations of use are re -examined with five years, taking into account the variations of the radiological situation and the needs of use of the land themselves.
The results of the study on chernobyl radioactive land
THE’experimental survey was made on an area of 100 hectares In the immediate proximity of the village of Mezhiliskaabout 60 km south-west of the Chernobyl nuclear power plant. The study area currently falls within the Resettment area And, at the time of the detection campaign, it was characterized by a mainly herbaceous plant cover of natural origin. During the research, within the experimental site they were taken overall 19 soil samples, each from a depth of 25 cm. Subsequently, a specific protocol has been developed aimed at determining the levels of contamination and the estimate of the absorption of radionuclides by typical agricultural crops for the pedological context examined, such as potatoes, cereals, corn and sunflower.
Scholars have focused attention on quantification concentrations in the soil of specific radioactive isotopes, such as 137CS, 90SR and Plutonium-239/240 (239Pu/240PU), expressed in kilobecquerl for kilogram (kbq/kg)unit of measurement of radioactivity and which represents the number of radioactive decayments to the second per unit of mass of the sample. The researchers then reported that the detected contamination levels were significantly lower At the safety limits defined by the national legislation in force for radioactive contaminants in agricultural soils, excluding therefore a radiological risk For the population, provided that an adequate soil monitoring program is maintained.
Also, considering that aextensive portion of land in the northern region of Ukraine, currently classified as area 2 and subject to restrictive constraints, has a density of contamination comparable or lower To those detected in the experimental soils analyzed in the study, the research group concludes that the cultivation of numerous agricultural species in these areas results potentially practicable. Although in successive stages it is essential to conduct in -depth assessments on the safety of both agricultural operators and final consumers, this investigation opens potential prospects For the recovery and revalization of vast agricultural areas contaminated by long -term radionuclides, not only in Ukraine but also in other regions of the world.
