Onsite NORM TENORM Treatment And Final Disposal Christian

On-site NORM/ TENORM Treatment And Final Disposal Christian Stiels, Reinhard Schmidt econ industries Gmb. H, Schiffbauerweg 1, 82319 Starnberg, Germany/ E-Mail: c. stiels@econindustries. com Introduction The terms Naturally Occurring Radioactive Material (NORM) and Technologically Enhanced Naturally Occurring Radioactive Material (TENORM) describe industrial wastes or by-products containing naturally occurring radioactive elements from the environment. These wastes are typically generated by mining, oil and gas industry and burning of fossil fuels such as coal. Potential NORM/ TENORM Hazards Potential hazards of NORM/ TENORM: • • • Ionising radiation exposure to personnel during storage Incidents/ accidents during transport Release to the environment during storage, transport, processing & final disposal / sequestration Best Practice NORM/ TENORM Management in Europe Due to geological reasons and high public awareness NORM/ TENORM waste management has a long history in Europe. Standards for NORM/ TENORM management and disposal have been tightened over the years. This led to fixed procedures regarded as Best Available Technology (BAT) for the NORM/ TENORM management. Typical NORM/TENORM management includes the following steps. • • On-site waste classification & pre- treatment • Identify level of radioactivity • Remove NORM Scale from piping, tools and equipment On-site or off-site removal of water, oil and mercury from waste matrix • Reduction of waste amount • Creating easy to handle material (bulk material) • Creating a waste material that can be chemically immobilized/ stabilized On-site or off-site chemical immobilization/ stabilization of remaining solids • Minimize leachability • Minimize emissions of radioactive particles (dust) • Enhance mechanical properties Safe transport and final disposal as long term stable material Final disposal in underground waste repositories or special landfill Figure 1: Typical NORM/TENORM waste material (Scale, separator sludge, cuttings) Figure 2: NORM/ TENORM vacuum thermal desorption and immobilization plant The level of radioactivity is determined and the waste is classified accordingly NORM/ TENORM scales attached to equipment or tools are removed by manual or automated high pressure jetting systems. For removal of scales not accessible for jetting chemical dissolution is used. Water, oil and mercury are removed from the waste matrix using vacuum thermal desorption. Particles with elevated radioactivity are solely present in the solids and remains within the dried solids. A dust filter prevents carry over of radioactive elements into the recovered condensates (water, oil, mercury). Immobilization of the remaining solids -containing the radioactive elements- is realized utilizing special cement. The material is cured into large blocks or into barrels. This reduces the surfaces of the waste and increases mechanical and chemical stability. Emission potential is significantly reduced. As the waste is immobilized it can be transported safely over long distances. The immobilized waste can be disposed of for long term sequestration in above or underground storage facilities depending on the level of radioactivity. Figure 3: Conceptional process of Best Practice NORM/TENORM waste management in Europe. Conclusions Treatment of NORM/ TENORM by the above described approach has been successfully applied in Europe on an industrial scale for several decades. The approach has proofed to be resilient against changes of different wastes and in different environments. However, in Australia a lack of legislation, public pressure and available sites approved for final disposal of treated NORM/ TENORM has prevented the adaptation of this treatment method. Once the political frame work has been established, the “European Model” of NORM/ TENORM waste management can be implemented easily. www. econindustries. com