Processing materials with natural radioactivity
Naturally Occurring Radioactive Materials (NORM) are present in the mineral feedstocks used by a wide range of industries, from fertiliser and pigment production to house brick manufacture and water treatment. NORM does not usually pose a significant hazard to workers or the public, but in some industrial processes radioactive content may become concentrated. In such cases, additional precautions are required for handling products or waste streams. Ensuring the safety of workers, or those using NORM, requires accurate, reliable, and efficient measurements of radioactivity both in industrial processes and in NORM products.
The EMRP project Metrology for processing materials with high natural radioactivity developed new and more accurate assay methods for measuring radioactivity in raw materials and waste streams, generated new NORM reference materials, and established innovative insitu methods for radioactive contamination monitoring.
- Improved laboratory methods for automating the preparation of NORM samples for analysis based on techniques used in the mining industry.
- Evaluated the performance of innovative pixel detectors, and developed new monitoring instrumentation including an alpha spectrometer enabled for relaying responses for quick on-site analysis.
- Devised an easy to follow method for determining the NORM radioactive fingerprint associated with the lead-210 radionuclide, an indicator for the presence of other NORM radionuclides in feedstocks, reducing assay complexity and costs.
- Conducted a comparison exercise using well-characterised reference materials, enabling labs that routinely measure NORM materials by gamma spectrometry to demonstrate measurement competence.
- Developed e-learning training materials for project managers and scientific staff in NORM- industries.
A long-lasting achievement from the project has been the establishment of a new NORM measurement infrastructure and increased accuracy in radioactive analysis at many newly joined EU member states National Measurement Institutes (NMIs). This collaborative project has improved end-user measuring systems and methods, in particular for in-situ use, and provided innovative, well-characterised radiation monitoring instrumentation for raw material selection across a wide range of European industries. Accurately determining a material’s radioactive content, whether from raw feedstocks or NORM waste streams, helps demonstrate compliance with the European Construction Products Directive requirements, the European Directive on radioactivity in drinking water, and the EU’s Basic Safety Standards. Better compliance with these directives boosts public safety, helps to eliminate technical trade barriers, and reduces the potential for trade disputes between EU.