Since the discussion of oil and gas NORM/TENORM can be extremely technical if you do not have a radiation safety background, the below topics are provided to provide practical information. Click on the hyperlink of the appropriate topic of your choosing.
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NATURALLY OCCURRING RADIOACTIVE MATERIAL
Naturally Occurring Radioactive Material (NORM) are materials of the Uranium-238 and Thorium-232 decay chains found in nature, and the primary isotopes of oil and gas NORM are radium-226, radium-228, radon-222, and their radioactive decay daughters.Naturally occurring materials not regulated under the Atomic Energy Act (AEA) whose radionuclide concentrations have been increased by or as a result of human practices are considered NORM.NORM does not include the natural radioactivity of rocks or background radiation, but instead refers to materials whose radioactivity is concentrated by controllable practices (or by past human practices).Background radiation comes from:Cosmic sourcesNon-technologically enhanced NORM (Oil and Gas NORM is often referred to as TENORM), including radon, except as a decay product of source or special nuclear material, andGlobal fallout as it exists in the environment from the testing of nuclear explosive devices or from past nuclear accidents, such as Chernobyl.
As Low As Reasonably Achievable (ALARA) is based on the idea that all materials that contain radiation or are radioactive pose a health risk, no matter how low the radiation level. In order to control worker protection, no worker must be exposed to more radiation than is necessary to perform the task.ALARA takes into account the state of technology, the economics of improvements in relation to the state of technology, the economics of improvements in relation to benefits to the public health and safety, and other societal and socioeconomic considerations, and in relation to utilization of radiation in the public interest. Exposure reducing tools are used to adhere to the ALARA principle.Exposure Reducing Tools are also referred to as the “Big Three”. These are tools or methods that are used in the radiation industry to prevent an individual from being exposed to more radiation than is necessary to perform the task.
GENERAL AND SPECIFIC LICENSEES
Oil and gas companies, who operate, process, use, store, or transfer NORM contaminated equipment are authorized by rule as general licensees. The Company (Licensee) must comply with the General License rules provided by the state in which they operate.A decontamination company who possesses a radiation license from an agreement state agency or the Nuclear Regulatory Commission (NRC) is referred to as a specific licensee. Any decontamination activity MUST be performed by a specifically licensed contractor; otherwise an unauthorized decontamination activity has been performed.Each specific licensee is required to have a Radiation Safety Officer (RSO) listed on the company’s radiation license. The RSO is an individual who has knowledge of and the authority and responsibility to apply appropriate radiation protection rules, standards, and practices, who must be specifically authorized on a radioactive material license, and who is the primary contact with the agency.Some states do not have NORM regulations; therefore, their radiation rules must be reviewed.
DECONTAMINATION VS. ROUTINE MAINTENANCE
Decontamination is the act of removing radioactive particles from an object, either intentionally or unintentionally. This activity is typically deemed a licensed activity, which requires a radioactive material license issued by a state agency.Routine Maintenance (On-site Maintenance) is when activities are performed on a periodic or scheduled basis for upkeep on equipment/facilities. These activities do not require confined space entry or respiratory protection. Maintenance, that provides a different pathway for exposure than is found in daily operations, and that increases the potential for additional exposure (such as the contaminates becoming airborne) is not considered routine. Any maintenance activity that does not meet this definition is non-routine maintenance, which is essentially a decontamination activity.Non-routine Maintenance is when activities are performed for upkeep on equipment/facilities that does not happen on a periodic or scheduled basis. In some instances these can take place in emergency or unforeseen situations. They can require confined space entry or respirator protection. Any maintenance that provides a different pathway for exposure than is found in daily operations, and that increases the potential for additional exposure (such as the contaminates becoming airborne) requires specifically licensed contractors.
A survey is an evaluation of the radiological conditions and potential hazards incident to the production, use, transfer, release, disposal, and/or presence of sources of radiation. When appropriate, such survey includes, but is not limited to, tests, physical examination of location of materials and equipment, measurements of levels of radiation or concentration of radioactive material present.Surveys are can be performed using two different special units; microroentgens per hour (µR/hr), and counts per minute (cpm).The roentgen is a measurement of radiation levels existing at any particular point in air where a radiation detector is positioned. The roentgen is the unit of measurement for radiation exposure, particularly gamma ray exposure when working with NORM. The microroentgen per hour (µR/hr) is the basic radiation unit over time used to provide an indication of the amount/concentration of NORM that is being emitted from an object, also known as exposure.Counts per minute (cpm) is a measurement of loose alpha and beta particle radiation contamination being emitted from a person or an object, which is measured with the Geiger-Mueller “pancake” probe. This unit is primarily associated with the process of surveying personnel called frisking. Gas-processing equipment and facilities are surveyed with the Geiger-Mueller “pancake” probe due to beta particle contamination that is not detectible by the scintillation probe.
OCCUPATIONAL AND GENERAL PUBLIC DOSES
Dose is a generic term that can mean the radiation that hits the body. Dose is measured in rem, which is the special unit of any of the quantities expressed as dose equivalent. The Rem is the unit of measurement for radiation that contacts the body, and is measured by a Thermouminescent Dosimeter (TLD) badge.Occupational dose is the dose received by an individual in the course of employment in which the individual’s assigned duties involve exposure to sources of radiation from licensed and unlicensed sources of radiation, whether in the possession of the licensee or other person. TLD badges are worn by occupational workers to measure their occupational dose. The employees who work for a specific license performing decontamination activities are occupational workers and they wear TLD badges. These employees perform decontamination activities on a daily basis.General Public dose is the dose received by a member of the public from exposure to sources of radiation released by a licensee, or to any other source of radiation under the control of a licensee. The employees of a general licensee, such as oil and gas operator employees, are considered members of the general public.Note that the OSHA regulations on Ionizing Radiation, 29 CFR 1910.1096 are written to address true occupational workers who wear TLD badges and work “in” the radiation industry, particularly with sealed sources of radiation. Oil and gas workers do not fit in this category, unless they are involved with pipe inspection, wireline activities, or other job functions that require them to be trained and badged to work with the radioactive material. Oil and gas workers are typically categorized as members of the general public even though they work “around” the NORM contamination. If they worked “in” the NORM contamination, they would be employed by a specific licensee and would be issued TLD badges.