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Highlights  Datamining was used for the construction of the NORM4Building database  Systematic radiological evaluation of by-products for use in concrete  Radiological evaluation of cement, concrete, ceramics and (phospo)gypsum  The datamining approach enables the construction of an updated detailed database

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Nuclear Power is a decarbonated technology of electrical energy generation. Using nuclear energy as a power source is currently considered as the best option in the fight against climate change. But the radioactive waste generated from nuclear power plants and their related facilities are matter of concern. Though the high level and intermediate level activity wastes are contained in small volumes (≤10%), significant volumes of lower activity wastes are generated. Metallic wastes are a major component of these radioactive wastes with about 500,000 tons expected in France alone, including 130,000 tons from steam generators. Majority of these metals are made of Stainless steel 316 alloy or Inconel 600. Under the effect of the primary circuit thermal-hydraulic constraints and irradiation, these the resulting corrosion products may be activated when close to the fuel, and be transported throughout the circuit. These products can be deposited on the surface of other metal components, causing contamination of the latter. The contamination can be adsorbed on the surface but can also diffuse in the oxide layers and sub-surface. The oxide layer is composed of an inner layer of Cr oxide under a layer of Ni and Fe oxide. Chemical decontamination is preferred due to the possibility of decontamination of difficult geometries and tube bends. In order to decontaminate these materials, it is important to dissolve the oxide layers chemically and a few micrometers of base metal where it could have diffused. An existing chemical method used to treat these materials is studied in this article, Chemical Oxidation Reduction Decontamination (CORD). Surrogate steel samples were prepared using high temperature induction heating and water vapour after sample preparation and cleaning. The oxide layer was characterised before treatment of the samples in the batch method at different concentrations and its effects are observed on the dissolution of the oxide layers. A protocol is being developed for the treatment of secondary waste effluents by multi-stage precipitation with a goal to reduce the total waste volumes and thus the volumes of ion exchange resins that would otherwise be needed.

Exposure to toxic heavy metal content in soil and inherent naturally occurring radioactive materials (NORM) needs to be monitored, especially after industrial accidents and remediation efforts. Just such an accident happened near Ajka city in Hungary; a large quantity of red mud flooded out from a reservoir. The afflicted area was remediated, and the red mud deposition technology was changed from a wet to a dry procedure. Concerns have been raised about potential hazards from airborne NORM dust in this area. The objectives of this study were to assess the use of explanted tobacco plants as an active biomonitoring system for airborne NORM dust and to reveal weather-related correlations of Po-210 in airborne dust. In 2011, 2012 and 2014, measurements were taken of the following at six monitoring sites in the polluted area and at eight sites in unpolluted areas: soil and tobacco plant Po-210 isotope levels, airborne Rn-222, Ra-226 in soil, Th-232 and K-40 radioactivity concentrations. The transfer factors (TFs) of tobacco were calculated yearly for these isotopes. Association of data with local weather features was determined. In 2012 (the windiest and driest year), the mean Po-210 activity concentrations of tobacco samples in polluted areas were significantly higher than in 2011 and in 2014 (p ¼ 0.044 and p ¼ 0.024, respectively). The mean TF of samples in 2012 was also significantly higher in tobacco plants grown in the polluted area compared to ones grown in unpolluted areas (p ¼ 0.020). These results presumably originate from red mud dust-particle adsorption on tobacco plant leaves. Tobacco plants are promising active bioindicators of airborne particulate pollution by Po-210 or other atmospheric NORM content.

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The radioactive waste produced from the construction of a nuclear power plant is a controversial topic. The resulting radioactive waste contains 60Co and 137Cs isotopes that are the most difficult to remove. Bentonite is widely used as an adsorbent for heavy metals. An important factor is the safe operation of waste management at a nuclear power plant to be built in Vietnam. Therefore, a method of degrading complexes of radionuclides and the adsorption of radionuclides onto Vietnamese Bentonite was implemented in this study. In current literature, UV radiation and heating with oxidising substances are used in general for degrading complexes of radionuclides. The experimental results for the adsorption of Co(II) and Cs+ onto VNB suggest that VNB can be used in the future for large-scale liquid waste treatment due to its low cost, high efficiency, and environmentally friendliness.