Development of synthetic scenarios to assess the transfer of radionuclides to groundwater from liquid discharges in NORM industries.

By-products and wastes from NORM (Naturally Occurring Radioactive Material) industries usually present enhanced concentration of naturally occurring radionuclides. Some of them are liquid, such as water from acid drainage sites, uranium mine tailings, or phosphogypsum ponds. There is considerable variability in the types of locations, size of water bodies, radionuclide concentration, type of water, hydrogeochemical characteristics of the site that can have a significant influence on the transfer of naturally occurring radionuclides to groundwater. Therefore, their occurrence in groundwater can pose a radiological hazard, since it can be used for irrigation, watering animals or drinking water, among others. In this study, we developed three different synthetic/theoretical scenarios in which most of these parameters are fixed after consulting the corresponding literature. Two scenarios are based on uranium tailings and a phosphogypsum stack with high radionuclide concentration that percolates into an aquifer; whereas in the third scenario the source term is a leaking pipe in the ground above the aquifer. The purpose of these scenarios is to determine the influence of several variables on the transfer of naturally occurring radionuclides to groundwater used for human consumption.