Identification of NORM Facilities in Bulgaria - Methodical Approach and Results

Bulgaria has been a member of the European Union since 2007. Consequently, the European standards and regulatory framework have to be implemented in the Bulgarian legislative system. As part of this process, the basic safety standards in the field of radiation protection (EU BSS), as laid down in the Council Directive 96/29/Euratom, have to be implemented. Title VII of the EU BSS concerns natural radiation sources and related work activities. Its implementation requires that each Member State ensure the identification of work activities that may be of concern regarding naturally occurring radioactivity. This identification has to be done by surveys or other appropriate methods. Guidance concerning the methods of such investigations is given in the recommendations contained in the European Commission report RP88, as well as in the pertinent literature describing the occurrence of radioactivity in industrial facilities. But practical experience has shown that a comprehensive overview of the radioactivity of NORM or TENORM in an individual facility is difficult to obtain in a single survey. Furthermore, even if an industry is not radiologically relevant today, it may become so after changes of feed materials, as well as changed or new technologies (for example, installation of dust filters). This necessitates an approach that takes into account the processes that may lead to the formation of NORM and thus allows the anticipation of the occurrence of radiologically relevant materials in the future. In order to comply with the requirements of Title VII of the EU BSS, desktop research and field investigations were carried out and the evaluated, the results of which were used to enable the Bulgarian Nuclear Regulatory Authority to complete the surveys and obtain a comprehensive picture of the situation concerning NORM industries in Bulgaria. Based on the findings in the field, a regulatory framework to address work activities and materials involving natural radioactivity was developed also. In the paper, the methodical approach for the survey and the results obtained are described. The results of this investigation have allowed the competent authority to decide on the level of the necessary regulatory regime of NORM related activities in Bulgaria. The method has turned out to be practicable and can be applied to regions or countries in which a systematic investigation of naturally occurring radioactivity in industrial sectors is necessary. (author)