To evaluate the environmental impact of old radioactive waste sites and to predict the spread of radioactive contamination through groundwater, monitoring boreholes were drilled at the waste disposal site and areas adjoining it on the south and west. Equipped with filter columns, these boreholes were designed to permit observation of the level, chemical composition, and radionuclide content of the groundwater.

Available data on the geological structure of the soil, permeability coefficients of subsurface horizons, groundwater level, and volume of radioactivity served as a basis for calculation of the groundwater flow structure and strontium-90 dispersal range.² Apparently due to a sharp increase in the groundwater level in the early 1990s, the groundwater flow structure changed, resulting in a risk of contamination beyond the Kurchatov Institute. In addition, according to a model created to predict strontium-90 dispersion, if remediation work is done on the temporary radioactive waste sites, the area of groundwater contamination with strontium-90 content exceeding the action level (5 Bq/L) will remain within the Kurchatov Institute buffer zone.³ If remediation activities are not performed, the contamination may spread further with groundwater beyond the disposal site, with the strontium-90 content exceeding the action level.

Initially, two alternative approaches to remediation of the radioactive waste disposal site were considered:

1. Creation of geophysically engineered barriers in the radionuclide migration pathways

2. Complete disposition of the waste sites and decontamination of radioactive soil

To estimate the cost of the first option, evaluations were made of the possibility of building engineered barriers to reduce substantially the spread of contamination by infiltration with simultaneous use of sorbents to extract strontium-90 from the groundwater. Zeolites and apatites were considered as sorbents, and underground leaching technologies were proposed to extract cesium-137 from soils.