NORM and TENORM All Naturally Occurring Radioactive Materials

NORM and TENORM: All Naturally Occurring Radioactive Materials where human activities have increased the potential for exposure in comparison with the normal situation. Human activities may lead to enhanced concentrations of radionuclide – often referred to as Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM ) – and (or) enhanced potential for exposure to naturally occurring radioactive materials in products, byproducts, residues and wastes.

U-238 4, 47 x 109 y Uranium series U-234 248, 000 y Pa-234 m 1. 17 min Th-234 24. 1 d Emission of beta particle Th-230 75, 400 y Isotope half-life Ra-226 1620 y Emission of alpha particle Rn-222 3. 82 d Po-218 3. 11 min Bi-210 5. 01 d Bi-214 19. 9 min. Pb-214 26. 8 min. Po-210 138 d Po-214 164 μs Pb-210 22. 3 y Pb-206 stable

Thorium series Th-232 14. 1 x 109 y Th-228 1. 91 y Emission of Beta particle Ac-228 6. 13 h Ra-228 5. 75 y Isotope half-life Ra-224 3. 62 d Emission of alpha-particle Rn-220 55. 6 s Po-216 145 ms Po-212 0. 299 s Bi-212 60. 55 min Pb-212 10. 64 h Pb-208 Stable

Naturally Occurring Radionuclides There are numerous naturally occurring radionuclides. The radionuclides most commonly found in nature include the following primordial radionuclides of terrestrial origin: – the uranium series (238 U and its decay products) – the thorium series (232 Th and its decay products) – potassium-40 (40 K)

Natural Radionuclides of Little Significance Numerous other naturally occurring radionuclides (e. g. the actinium series (235 U and its decay products), carbon 14 (14 C) and other cosmogenic radionuclides derived from cosmic particle and rays (e. g. 7 Be)) can occur in nature however these are of little significance in terms of radiation exposures.

NORM industry candidates • • • Mining and processing of uranium ores Rare earths mining/extraction Thorium extraction & use Niobium extraction Oil and gas (scales, sludge, produced water, comtaninated sand/soils) Phosphate industry (residues from mining and fertilizers production) Zircon & zirconia Ti. O 2 pigment production Metals production (Sn, Cu, Al, Fe, Mg, Zn, Pb) Water and waste treatment residues (filters, sludge) Energy production including coal power production, geothermal energy production. Miscellaneous industrial sources and consumer products such as, production of clay and ceramics, glazed tableware with elevated levels uranium and/or thorium, and small industrial sources such as welding rods containing elevated levels of thorium, as well as scales, sludge and contaminated filters from different types of processing, ………… etc.

NORM in oil gas production • Scales or hard deposits in production tubulars and topside equipment which has been in direct contact with the production stream, • Contaminated sludge, sand, clay, heavy oil in the production system (separators, skimmer tanks. . . etc. ), • Enhanced levels of natural radionuclides in produced water, • contamination soils, sand, lakes/water pounds, ground water resources and sea water, • Thin films or condensates and contaminated steel (lead 210) in production, transport and storage systems in gas production (and/or in mixed oil-gas production), • NORM residues in decommissioning of production installations and restoration of NORM contaminated areas.

The main forms of appearance of NORM in oil and gas production • Radium scales , Radium sludge • Lead deposits , Lead films • 226 Ra, 228 Ra, 224 Ra , & progeny • 210 Pb , & progeny • Hard deposits containing sulphates and carbonates of Ca, Sr, Ba • wet parts of production installations • well completions • Sand, clay, paraffin, heavy metals • separators • skimmer tanks • Stable lead deposits • oil & gas treatment and transport

NORM residues • Many NORM residues are produced in very large volumes, although the activity concentration of radionuclides is relatively low. • However, there are some residues where the volumes are smaller but the levels of radioactivity are relatively high. • There is also the possibility that a NORM residue from one industry may be regarded as a raw material or a feedstock for further processing.

NORM residues, cont. • Residues may be chemically toxic and/or radioactive, • Residues can range from dry solids (varying from rocks to fine powders), • Other chemical constituents within the material may include heavy metals, inorganic elements (e. g. arsenic) and various organic compounds, • The potential for such non-radiological substances needs to be considered when planning the management of NORM residues.

NORM residues cont. • NORM residues come in many forms, including: – Scales from formation water from oil and gas production – Sludge from water filtration systems – Residues from metal processing e. g. red mud, tailings , slag, • NORM residues are usually characterised by being in large volumes with low specific levels of radioactivity e. g: – Uranium mill tailings and phosphogypsum • NORM residues can also be small volumes containing high levels of specific radioactivity e. g. – Sludge from water treatment plants; - scale from oil & gas pipelines

Example of NORM residues production : Oil and Gas Industry • Dissolved matter in formation water • Transport with produced water • Deposition on insides of pipes, valves, vessels • The water contained in oil and gas formations contains 228 Ra, 226 Ra and 224 Ra dissolved from the reservoir rock, together with their decay progeny. • When this water is brought to the surface with the oil and gas, changes in temperature and pressure can lead to: • the precipitation of radium rich sulphate and carbonate scales on the inner walls of production equipment (e. g. pipes, valves, pumps).

Hazards of NORM • Because NORM scale generally contains so little activity, the external radiation field is generally low. However some old tubular, separators or pumps may give measurable radiation fields. • Because of the high alpha content, NORM scale is a significant internal hazard. • Requirement needs to stop NORM scale particles being inhaled or ingested. • precautions should be taken when working with NORM.

Source Term Characterization v. Dissolved radium either remains in solution in the produced water or, if the conditions are right, precipitates out in scales or sludge, equipment may contain residual quantities of NORM-contaminated water, scale, or sludge that can cause exposure problems when the equipment is taken offline for maintenance, repair, or replacement.

v. Numerous surveys had been conducted by industry and state agencies to characterize the occurrence and distribution of NORM. v Unfortunately, most of the data from these surveys are not readily available. vbecause they have been collected by private companies and the lack of access to data.

v. Data published from some of the earlier surveys indicate that total radium concentrations typically range from undetectable levels to several thousand Pico curies per liter or gram. v. Anomalously high concentrations up to 15. 170 MBq/Kg in scale v 25. 900 MBq/Kg in sludge , v 203 k. Bq/Kg in water, vin more recent studies, Available data indicate that total radium concentrations range from undetectable levels to 103. 600 MBq/Kg in most produced water.

Scale The source term concentrations used in this assessment were based on the scale and sludge composite concentrations used in a risk assessment conducted by the EPA and the state of Louisiana, v Total radium concentrations in scale typically range from undetectable levels to concentrations as high as 151. 700 MBq/Kg have been reported. v The median concentrations for total radium in scale was 17. 760 k. Bq/Kg (13. 320 k. Bq/Kg for Ra-226 and 4. 280 k. Bq/Kg for Ra-228). v The EPA estimates that approximately 25, 000 tons of NORM-contaminated scale is generated annually by the petroleum industry. v EPA=U. S. Environmental Protection Agency

Sludge v. Sludge deposits consist of accumulations of heavy hydrocarbons, produced formation sand, and minor amounts of corrosion and clay debris that settle out of suspension in some oil field equipment. v NORM accumulates in sludge when radium co precipitates with silicates and carbonates inside piping, separators, heater/ treaters, storage tanks, and any other equipments.

v. NORM of sludge concentrations range from undetectable levels to high concentration as 25. 900 MBq/Kg had been documented. v. The median concentrations for total radium in sludge was 2. 775 k. Bq/Kg , (2. 072 k. Bq/Kg for Ra 226 and 0. 703 k. Bq/Kg for Ra-228). v. The EPA estimates that approximately 225, 000 t of NORM contaminated sludge is generated annual.

Norm Concentrations in Scales Types of NORM residues

Norm Concentrations in Sludge Types of NORM residues

Natural gas production and processing • equipment may be contaminated with a thin film of Pb-210 plated onto interior surfaces. Lead-210 sometimes is produced along with natural gas partitioned mainly between the propane and ethane fractions. • median exposure levels for gas processing equipment range from 2 to 76 μR/h above background, • ( background level = 7 μR/h). • Maximum exposure levels had been measured as 5, 300 μR/h in surveys of scale or sludge inside the equipment.

For Occupational Health Purposes • Working with NORM materials can result in exposure to gamma radiation and the inhalation of long lived alpha emitting radionuclides. • The radionuclide composition of the NORM is quantified as this assists in the compilation of the occupational safety assessments and the interpretation of the dust sampling results. • The bioassay of workers (e. g. urine sampling for uranium).

Exposure Pathways to Humans - Atmospheric pathways: - Inhalation of radon and its daughters. - Inhalation of radioactive particulates (dust). - Terrestrial pathways: • Ingestion of contaminated foodstuffs. • External irradiation. -Aquatic pathways: • Ingestion of contaminated water. • Ingestion of foods produced using irrigation, fish and other aquatic biota.

NORM Contaminated Scrap

Contaminated Items

Scrap Items from a NORM Facility

NORM Scales (Pipes)

Scale and Sludge

Disposal of Production Water on Purpose to Evaporate

Disposal of scale and sludge

Summary-1 • Many types of naturally occurring radionuclide are found throughout the environment. • The most important in terms of their dose contribution are the primordial radionuclides of the uranium and thorium decay chains. • The decay chains contain a complex mixture of radionuclides with widely varying physical and chemical properties. • Accumulations of materials can result in significant gamma radiation and dust concentrations in the workplace,

Summary - 2 • Non-equilibrium radionuclide mixtures can occur, • The mixtures need to be properly characterized, • Both workplace and personal monitoring may be required, • Surface contamination monitoring will be used to assess , material and dust control systems. • In most types of samples the most important NORM radionuclides can be analyzed utilizing XRF and Hp. Ge equipment and methods. • Sites contaminated by historical NORM residues are a common phenomena worldwide.

Summary-3 • Contaminated sites and materials may be used by the public resulting in radiation exposures. • Monitoring is required throughout the life of the facility. • The monitoring of NORM facilities is complicated by the presence of natural background radiation. • Monitoring and surveillance are essential to provide assurance that the NORM facility is operating in a safe manner in accordance with the regulatory requirements.

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