THE PROBLEMS OF UTILIZING INDUSTRIAL BY-PRODUCTS CONTAMINATED WITH NATURAL RADIONUCLIDES IN CONSTRUCTION

摘要

Two examples of industrial by-products having a slightly elevated content of radionuclides are considered: coal fly ash and phosphogypsum. The properties of both are reviewed and the advantages of their re-using in construction are shown, as well as the problems caused by elevated content of chemical/radioactive contaminants. The problem of utilizing such byproducts in construction is discussed. Radiological aspects and legislation issues are analyzed. The tendency to develop stricter environmental norms observed in the last years in both national and international scale is discussed. This tendency sometimes faces the difficulty with the application of the strict environmental norms. The reasons and possible methods of solving the difficulties with legislation and quality control are discussed. As an example, the first Israeli Standard 5098 regulating radioactivity in building products is analyzed and compared to the Radiological Protection Principles Concerning the Natural Radioactivity of Building Materials Principles of Radiation (Radiation Protection 112, European Commission). Different methods of purification of removal of radioactive impurities are reviewed. The new approach based on the topochemical treatment of the material is described. As preliminary tests show, the radium content in phosphogypsum can be significantly decreased. Economical and environmental aspects of processing phosphogypsum for environmentally friendly construction are discussed.