Geohazards due to technologically enhanced natural radioactive wastes

Human activities can modify naturally occurring radioactive material (NORM) into technologically enhanced naturally occurring radioactive material (TENORM) as a result of industrial activities. Most of these industries do not intend to work with radioactive material a priori. However, whenever a uranium- or thorium-bearing mineral is exploited, NORM-containing by-products and TENORM-contaminated wastes are created. The industrial use of NORM can result in non-negligible radiation exposure of workers and members of the public, exceeding by far the radiation exposure from nuclear technologies. For decades, millions of tons of NORM have been released into the environment without adequate control or even with the lack of any control. Various technologies have been developed for the control of NORM wastes. The paper discusses the merits and limitations of different NORM-waste management techniques, such as Containment, Immobilization, Dilution/Dispersion, Natural Attenuation, Separation, and - as an alternative - Cleaner Technologies. Each of these methods requires a comprehensive risk-benefitcost analysis.