What is NORM?
The radionuclides radium, uranium, thorium and potassium, as well as their radioactive decay products, radium and radon, are naturally occurring in the environment1. The activity concentrations of these radioactive elements in minerals, ores and soil, known as naturally occurring radioactive materials, or, ‘NORM’ for short, are typically low2.
When people get involved
However, when people extract these minerals from the ground and chemically or physically process them, the radionuclides can become unevenly distributed2.
NORM is then classified as Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM)1. The radiological, physical and chemical properties of the materials have been altered by human processes, leading to increased potential for human and environmental exposure1. These human processes include2:
- Mining and milling of metalliferous and non-metallic ores
- Coal, oil and gas production
- Extraction and purification of water
- Generation of geothermal energy and production of industrial minerals, including phosphate, clay and building materials
TENORM can exist in various forms throughout these industrial processes: as ores, feedstock, intermediate product, end-product, by-product or process residue2.
A noteworthy example
An interesting case study is one of nature’s very own nuclear reactor in Okla, Gabon, Africa operating approximately 1.7 billion years ago3. French scientists in 1972 determined that due to the fission in a natural uranium ore deposit, the amount of U-235 was disproportionately low in comparison to its common isotopic pairs.
The need for NORM and TENORM monitoring
Due to the potential for increased radiation exposure to workers, the public and the environment from these activities, TENORM needs to be monitored.
For instance, the Environmental Protection Agency of Romania complete routine measurements and exercises to monitor possible radioactive contamination in air, soil and water. They use Kromek’s RayMon to characterise environmental radioactivity, including TENORM, to help inform next steps in emergencies and requested interventions. Monitoring TENORM is also necessary at Oil and Gas legacy sites. TENORM is a common waste by-product of oil and gas production, often accumulating as waste materials in pipes, plants and machinery. Petrotech, a product and service provider for the upstream and downstream oil and gas sector, deployed Kromek’s Quant RayMon on site to effectively identify and remove TENORM debris.
With high levels of industrial activity in the natural environment, people are likely to encounter NORM and alter its natural distributions.
Therefore, by having reliable radiation detectors in place accurately classifying the radioisotopes and their associated dose and/or activity present at a target site, TENORM or NORM can be identified, and the appropriate action taken to control the source and to also minimise further contamination and harmful exposure.
Sources
1 – Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM) | US EPA
2 – Naturally occurring radioactive material | IAEA
3 – The World’s Only Natural Nuclear Reactor | Science History Institute
Let no NORM go unnoticed
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