METRONORM

EMRP

Programme

The science of measurement – metrology – is important for scientific research, industry and our everyday lives, as the demand for measurements with high accuracies and low uncertainties continues to increase.

The European Metrology Research Programme (EMRP) enables European metrology institutes, industrial organisations and academia to collaborate on joint research projects within specified fields.

These collaborative efforts will accelerate innovation in areas where shared resources and decision-making processes are desirable due to economic factors and the distribution of expertise across different countries and sectors.

The EMRP is implemented by EURAMET, organised by 23 National Metrology Institutes (NMIs), supported by the European Union.

Project MetroNORM

Background

Naturally occurring radionuclides are present in many natural resources. Industrial activities that exploit these resources may lead to enhanced potential for exposure to NORM ‘Naturally Occurring Radioactive Materials’ in products, by-products, residues and wastes. Industries working with raw materials containing naturally occurring radioactive materials (NORM industries) produce large amounts of waste. These waste materials, generated from current and past activities, constitute a huge economic and ecological burden if they are not properly disposed of or re-used as input materials for the industry. The recycling and re-use of waste material support the use of “cleaner technologies” and result in cost savings.

The radioactivity content of mineral feedstocks and process residues creates a need to control exposure to workers and members of the public in accordance with the IAEA Safety Standards: “In commercially exploited rare earths deposits, the level of thorium and uranium, depending on the type of mineral and its region of occurrence, generally exceed the worldwide median values for soil by up to 200 times of thorium and up to 30 times in the case of uranium”.

When such minerals are being handled or processed, it is clearly necessary to determine the nuclides present and their activity concentrations as accurately as possible. Reference materials will be needed to validate the radioanalytical procedures involved as well as methods for analysis and interpretation of the results.

Need for the project

Traceable, accurate, and standardised measurement methods and systems, in particular for in-situ applications, are needed to decide on the re-use of waste materials without increasing costs whilst avoiding contamination of the environment and exposure of the public. Ionising radiation measurement in the recycling industry currently focuses on artificial radionuclides. Natural radionuclides are often taken as part of the natural background, regardless of their concentration. A reliable measurement of natural radionuclides is required to ensure that the raw materials brought into the industrial process will not cause, as far as possible, enhanced activity levels in the final products and in the waste.

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The production in NORM industry facilities must be effective and safe and must not endanger the health of personnel and the population or result in environmental pollution. The waste must be identified and precisely measured using traceable standardised methods. For this purpose, laboratory and on-site measurement systems must be developed, calibrated and verified. Improvement of decay data is needed for selected natural radionuclides. To ensure correct and accurate measurement, all measurement systems must be calibrated in a traceable way with calibration standards and reference materials that are adapted in an appropriate manner to the real composition and geometry of measured materials.

Scientific and technical objectives

  • Development of measurement systems, methods and technique including in-situ systems which support innovative industrial processing of resources containing naturally occurring radioactive material.
  • Design of traceable measurement procedures (as input to e.g. CEN/CENELEC standards) for industrial NORM raw material, products, by-products, residues and waste.
  • Development and establishment of traceable metrological reference materials and standard sources needed for calibration purposes for NORM measurement.
  • Improvements to decay data for selected natural radionuclides of the 238U,235U decay chains, and to the rare earth element 138La, focusing on decay chains description and gamma-ray intensities and half-life improvement.
  • Testing of developed systems, standards and reference materials in industrial processing situations.

Expected results and potential impact

Within the JRP new methodologies and measurement devices will be developed for measurement of natural radionuclides, new reference materials will be used for their calibration with traceability to national standards of partnering countries and nuclear data of natural radionuclides will be improved so that as many as possible descendants of uranium and thorium decay chains could be accurately measured. Stakeholders and end-users will be involved in the project to maximise the impact. The workshops will be organised for NORM and TENORM facilities, nuclear regulators, standardisation bodies and measurement devices and calibration sources manufacturers to present them the results of the research. The expected results of the JRP are:

  • Laboratory measurement systems and procedures for the measurement of natural radionuclides: New methods and traceable measurement system development with total rel. uncertainties lower than 10% (k=1).
  • On-site measurement systems and procedures for the measurement of natural radionuclides: New methods and traceable measurement system development with total rel. uncertainties lower than 10% (k=1).
  • Calibration standards and reference materials: Development of calibration standards and reference materials traceable to national standards for natural radionuclides measurement adapted to the needs of the developed laboratory and on-site measurement systems and adjusted to the typical composition of materials and activity levels relevant for measured materials with total rel. uncertainties lower than 10 %.
  • Nuclear data improvement for:
    • 238U series: solving of discrepancies in decay scheme data
    • 235U series: improved decay schemes
    • 238U series and 235U series: gamma- rays intensities known with better accuracy
    • 232Th series: improved decay schemes
    • 138La: standardisation
    • Recommendations for the radionuclide activity analyse of NORM samples

The JRP will also have an impact with the development of standardised traceable measurement methods for NORM industries on relevant EC Directives and regulations.