From raw materials to NORM by-products

Abstract

© 2017 Elsevier Ltd and Rob Wiegers All rights reserved. Naturally occurring radionuclides are present in the Earth crust; however, their distribution is not homogeneous. When primary or secondary raw materials containing relatively low concentrations of naturally occurring radionuclides are introduced in an industrial process then the radionuclides can become more concentrated in the produced (by-)products. For example, during the production of purified metals, throughout the purification process, also other elements, such as naturally occurring radionuclides, become concentrated in the by-products. In order to assure radiation protection of the population, it is important to map the potential exposure for workers and the general public. There is an extensive literature available regarding the presence of naturally occurring radionuclides in various by-products; however, it can be hard to review and even to interpret for the regulators and members of the industry in order to assure the safe use of by-products for example in construction.To solve this problem data mining and text processing have been applied to the ever-increasing numbers of publications (More than 39,000 filtered publications have been processed up to the Jan. 6, 2017), and the NORM4Building database has been compiled based on the analysis of the collected data. Based on this database using text analysis methods the most NORM prone raw materials and industries have been identified. This chapter gives a concise overview on the parameters to be considered during the selection of NORM by-products as feedstock for the construction industry, specifically for the production of cement, concrete, and ceramics. In the frame of this chapter the technical and radiological properties of the most representative industrial processes (such as coal mining and combustion; iron and steel production; the alumina, the zirconia, and the phosphate industry; etc.) and their by-products are discussed, especially considering the needs of the construction industry and the new European Basic Safety Standards.