The Role of Drainage Systems in Ensuring the Barrier Functions of the Chornobyl Exclusion Zone

Abstract

Drainage systems in the Chornobyl exclusion zone (CHEZ) are considered in the context of this zone's performance of barrier functions to contain the water transport of radionuclides beyond its borders. The principles of assessing the barrier resistance of catchment basins are described, taking into account landscape features and the dynamics of 90Sr removal; the role of drainage systems in the formation of removal of radionuclides at different stages of post-accident works and during periods of different water levels was analyzed, and effective water protection measures were proposed. Natural landscape and geochemical characteristics of catchments, not water protection measures and structures, are responsible for the formation of stable barrier functions. Various man-made facilities mostly only worsen the barrier capacity of the catchment in the long term; for example, the additional artificial drainage network due to the possibility of its regulation helps to reduce the removal of radionuclides in low-water years, but in high-water, it significantly weakens the barrier functions.