Геохімія техногенезу (Dec 2023)
CLIMATE CHANGES AND SITE DISPOSAL OF OBJECTS ON THE CHRONOBYL STATION SITE
Abstract
Currently, in the Exclusion Zone at the site of the Chornobyl NPP, work is being carried out on the final closure and conservation of power units 1–3, the feature of which is the presence of a high-capacity channel uranium-graphite reactor (RVPK). During operation, the reactor graphite becomes radioactive due to the accumulation of the long-lived radionuclide 14C in the graphite. An additional contribution is made by the indicated radioactivity of technological impurities (36Cl, 60Co) and spills of fission products and fragments of nuclear fuel. The main problem of the decommissioning of nuclear installations from the RVPK is related to the need to choose optimal methods of handling large volumes of spent graphite. The possibility of applying the technology of near-surface disposal of decommissioned uranium-graphite reactors of the RVPK, known as the “green mound”, to power units 1–3 of the Chernobyl NPP was considered. Natural factors have been identified, the possible action of which during the time required for the decay of radionuclides 14C and 36Cl to an acceptable level, may lead to the destruction of near-surface storage facilities for disposal at the Chernobyl NPP site. These factors determine the rehabilitation of the river valley of the Pripyat River and the vulnerability of surface disposal repositories to the effects of cyclical climate changes. Climatic changes should be taken into account when making decisions on on-site disposal, given that the processes of decay of long-lived radionuclides, degradation of matrices of incorporated radioactive waste, and the duration of protective barriers in terms of time are relevant to the dynamics of climate change. The need to take into account the impact of global climate changes on the intensity of changes in the geomorphological characteristics of the locations of “green mounds” was noted. A particularly dangerous and powerful natural factor that will inevitably lead to the destruction of the “green mounds” is the influence of probable glaciation. The relevance of solving the scientific task of a complex combination of knowledge regarding the formation of the physical and geographical features of Polissia in the last 200 thousand years with the modeling of climate changes in the future 100 thousand years is emphasized, which will allow to reasonably accept or reject the very idea of near-surface burial of long-lived radioactive waste at the Chernobyl NPP site.
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