The European NORM Association (ENA)-promoting radiation protection in the field of norm in Europe.

The European NORM Association (ENA) was founded in 2017, merging previously informal European networks. It has the statute of an International Non-profit Organization established under Belgian Law. The objective of ENA is to promote and advance radiation protection in the context of exposure to NORM. It operates as a European platform and forum for discussion, dissemination and exchange of information, training and education and by supporting scientific knowledge and new directions of research related to NORM issues. A key activity of ENA is to share practical solutions. To this end, ENA gathers radiation protection practitioners, regulators, scientists and industry representatives in order to support the management of NORM in compliance with European standards and according to best practices. Since its foundation, ENA has organized three workshops where topical issues on NORM have been discussed. It has established close working relationships and links with IAEA, HERCA, IRPA and other international initiatives-getting a recognition at international level. ENA has set up working groups on NORM in the industry, in the environment, in building materials and, as recently as in 2021, a working group on decommissioning of NORM facilities. A series of webinars have been organized to present case studies on NORM decommissioning and discuss associated challenges and practical solutions.

The issue of Cs-137 in firewood and biomass combustion: a review.

In large parts of Europe, the Chernobyl accident of 1986 caused fallout of Cs-137. This led to the uptake of Cs-137 in trees or other materials used for bioenergy production or as firewood for domestic purposes. This Cs-137 may concentrate in the ashes of the combustion process in such a way that the clearance level of 100 Bq per kg, defined in Directive 2013/59/Euratom (EU BSS), may consequently be exceeded. There is currently no clear consensus in Europe regarding the regulatory approach to this issue: should the import and use of Cs-137 contaminated biomass and its ashes be considered as a planned exposure situation or rather as an existing exposure situation? If considered as an existing exposure situation, which reference level should be applied? We compare the approaches in various European countries, such as Finland, Norway, Sweden, Belgium and the Netherlands. Results of a recent measurement campaign performed in Belgium on firewood imported from Belarus, Ukraine and other countries show a quite large range of Cs-137 activity concentration in firewood. Analysis of samples from biomass combustion confirms that the clearance level of 100 Bq per kg Cs-137 may be exceeded even when the activity concentration in the initial pellet is trivial. A review of dose-assessment studies performed by STUK and from the literature is presented. The general context of biomass energy production is sketched: for instance, in the Netherlands, 40 large biomass firing plants (capacity > 10 MW) are operational and some 20 more are already planned. The fly ashes from the biomass combustion may be a valuable resource for the construction industry, and the issue of Cs-137 contamination is connected with the requirements of the EU BSS regarding the natural radioactivity of building materials. Assessing the impact of Cs-137 contamination and clarifying regulations in the frame of a graded approach are important elements in this context.