Naturally occurring radioactive materials (NORM) and technologically enhanced naturally occurring radioactive materials (TENORM) consist of materials, usually

industrial waste Industrial waste is the waste produced by industrial activity which includes any material that is rendered useless during a manufacturing process such as that of factories, mills, and mining operations. Types of industrial waste include dirt and ...

s or by-products enriched with radioactive elements found in the environment, such as

uranium Uranium is a chemical element; it has chemical symbol, symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Ura ...

thorium Thorium is a chemical element; it has symbol Th and atomic number 90. Thorium is a weakly radioactive light silver metal which tarnishes olive grey when it is exposed to air, forming thorium dioxide; it is moderately soft, malleable, and ha ...

and

potassium-40 Potassium-40 (K) is a long lived and the main naturally occurring radioactive isotope of potassium. Its half-life is 1.25 billion years. It makes up about 0.012% (120 parts-per notation, ppm) of natural potassium. Potassium-40 undergoes four dif ...

(a long-lived beta emitter that is part of natural potassium on earth) and any of the products of the

decay chain In nuclear science a decay chain refers to the predictable series of radioactive disintegrations undergone by the nuclei of certain unstable chemical elements. Radioactive isotopes do not usually decay directly to stable isotopes, but rather ...

s of the former two, such as

radium Radium is a chemical element; it has chemical symbol, symbol Ra and atomic number 88. It is the sixth element in alkaline earth metal, group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, ...

and

radon Radon is a chemical element; it has symbol Rn and atomic number 86. It is a radioactive noble gas and is colorless and odorless. Of the three naturally occurring radon isotopes, only Rn has a sufficiently long half-life (3.825 days) for it to b ...

Produced water Produced water is a term used in the oil industry or geothermal industry to describe water that is produced as a byproduct during the extraction of oil and natural gas, or used as a medium for heat extraction. Water that is produced along with t ...

discharges and spills are a good example of entering NORMs into the surrounding environment. Natural radioactive elements are present in very low concentrations in Earth's crust, and are brought to the surface through human activities such as oil and gas exploration, drilling for

geothermal energy Geothermal energy is thermal energy extracted from the crust (geology), crust. It combines energy from the formation of the planet and from radioactive decay. Geothermal energy has been exploited as a source of heat and/or electric power for m ...

mining Mining is the Resource extraction, extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agriculture, agricultural processes, or feasib ...

, and through natural processes like leakage of

gas to the atmosphere or through dissolution in ground water. Another example of TENORM is coal ash produced from coal burning in power plants. If radioactivity is much higher than background level, handling TENORM may cause problems in many industries and transportation. If a mineral has naturally occurring radioactive material present, the

tailings In mining, tailings or tails are the materials left over after the process of separating the valuable fraction from the uneconomic fraction (gangue) of an ore. Tailings are different from overburden, which is the waste rock or other material ...

may have a higher concentration of radioactive substance than the ore had. By mass perhaps the biggest example of such material is

phosphogypsum Phosphogypsum (PG) is the calcium sulfate hydrate formed as a by-product of the production of fertilizer, particularly phosphoric acid, from phosphate rock. It is mainly composed of gypsum (). Although gypsum is a widely used material in the cons ...

where radium-sulfate is left with the gypsum that results from treating

apatite Apatite is a group of phosphate minerals, usually hydroxyapatite, fluorapatite and chlorapatite, with high concentrations of Hydroxide, OH−, Fluoride, F− and Chloride, Cl− ion, respectively, in the crystal. The formula of the admixture of ...

with sulfuric acid to extract

phosphoric acid Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, ...

. Another example is in rare earth-mining where ores such as monazite may contain thorium and its decay products which are subsequently found enriched in the tailings.

NORM in oil and gas exploration

Oil and gas TENORM and/or NORM is created in the production process, when produced fluids from reservoirs carry sulfates up to the surface of the Earth's crust. Some states, such as

North Dakota North Dakota ( ) is a U.S. state in the Upper Midwest, named after the indigenous Dakota people, Dakota and Sioux peoples. It is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minneso ...

, use the term "diffuse NORM". Barium, calcium and strontium sulfates are larger compounds, and the smaller atoms, such as radium-226 and radium-228, can fit into the empty spaces of the compound and be carried through the produced fluids. As the fluids approach the surface, changes in the temperature and pressure cause the barium, calcium, strontium and radium sulfates to precipitate out of solution and form scale on the inside, or on occasion, the outside of the tubulars and/or casing. The use of tubulars in the production process that are NORM contaminated does not cause a health hazard if the scale is inside the tubulars and the tubulars remain downhole. Enhanced concentrations of the radium 226 and 228 and the daughter products such as lead-210 may also occur in sludge that accumulates in oilfield pits, tanks and lagoons. Radon gas in the natural gas streams concentrate as NORM in gas processing activities. Radon decays to lead-210, then to bismuth-210,

polonium-210 Polonium-210 (210Po, Po-210, historically radium F) is an isotope of polonium. It undergoes alpha decay to stable 206Pb with a half-life of 138.376 days (about months), the longest half-life of all naturally occurring polonium isotopes (210– ...

and stabilizes with lead-206. Radon decay elements occur as a shiny film on the inner surface of inlet lines, treating units, pumps and valves associated with propylene, ethane and propane processing systems. NORM characteristics vary depending on the nature of the waste. NORM may be created in a crystalline form, which is brittle and thin, and can cause flaking to occur in tubulars. NORM formed in carbonate matrix can have a density of 3.5 grams/cubic centimeters and must be noted when packing for transportation. NORM scales may be white or a brown solid, or thick sludge to solid, dry flaky substances. NORM may also be found in oil and gas production produced waters. Cutting and reaming oilfield pipe, removing solids from tanks and pits, and refurbishing gas processing equipment may expose employees to particles containing increased levels of alpha emitting radionuclides that could pose health risks if inhaled or ingested. NORM is found in many industries including * The coal industry (mining and combustion) * Metal mining and smelting * Mineral sands (rare earth minerals, titanium and zirconium). * Fertilizer (phosphate) industry * Building industry

Hazards

The hazards associated with NORM are inhalation and ingestion routes of entry as well as external exposure where there has been a significant accumulation of scales.

Respirator A respirator is a device designed to protect the wearer from inhaling hazardous atmospheres including lead, lead fumes, vapors, gases and particulate matter such as dusts and airborne pathogens such as viruses. There are two main categories o ...

s may be necessary in dry processes, where NORM scales and dust become air borne and have a significant chance to enter the body. The hazardous elements found in NORM are radium 226, 228 and radon 222 and also daughter products from these radionuclides. The elements are referred to as " bone seekers" which when inside the body migrate to the bone tissue and concentrate. This exposure can cause bone cancers and other bone abnormalities. The concentration of radium and other daughter products build over time, with several years of excessive exposures. Therefore, from a liability standpoint an employee that has not had respiratory protection over several years could develop bone or other cancers from NORM exposure and decide to seek compensation such as medical expenses and lost wages from the oil company which generated the TENORM and the employer. Radium radionuclides emit alpha and beta particles as well as gamma rays. The radiation emitted from a radium 226 atom is 96% alpha particles and 4% gamma rays. The

alpha particle Alpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. They are generally produced in the process of alpha decay but may also be produce ...

is not the most dangerous particle associated with NORM, as an external hazard. Alpha particles are identical with helium-4 nuclei. Alpha particles travel short distances in air, of only 2–3 cm, and cannot penetrate through a dead layer of skin on the human body. However, some radium alpha particle emitters are "bone seekers" due to radium possessing a high affinity for chloride ions. In the case that radium atoms are not expelled from the body, they concentrate in areas where chloride ions are prevalent, such as bone tissue. The

half-life Half-life is a mathematical and scientific description of exponential or gradual decay. Half-life, half life or halflife may also refer to: Film * Half-Life (film), ''Half-Life'' (film), a 2008 independent film by Jennifer Phang * ''Half Life: ...

for radium 226 is approximately 1,620 years, and will remain in the body for the lifetime of the human — a significant length of time to cause damage.

Beta particle A beta particle, also called beta ray or beta radiation (symbol β), is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus, known as beta decay. There are two forms of beta decay, β− decay and � ...

s are

electron The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary charge, elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up qua ...

s or

positron The positron or antielectron is the particle with an electric charge of +1''elementary charge, e'', a Spin (physics), spin of 1/2 (the same as the electron), and the same Electron rest mass, mass as an electron. It is the antiparticle (antimatt ...

s and can travel farther than alpha particles in air. They are in the middle of the scale in terms of ionizing potential and penetrating power, being stopped by a few millimeters of plastic. This radiation is a small portion of the total emitted during radium 226 decay. Radium 228 emits beta particles, and is also a concern for human health through inhalation and ingestion. The

gamma ray A gamma ray, also known as gamma radiation (symbol ), is a penetrating form of electromagnetic radiation arising from high energy interactions like the radioactive decay of atomic nuclei or astronomical events like solar flares. It consists o ...

s emitted from radium 226, accounting for 4% of the radiation, are harmful to humans with sufficient exposure. Gamma rays are highly penetrating and some can pass through metals, so

Geiger counter A Geiger counter (, ; also known as a Geiger–Müller counter or G-M counter) is an electronic instrument for detecting and measuring ionizing radiation with the use of a Geiger–Müller tube. It is widely used in applications such as radiat ...

s or a scintillation probe are used to measure gamma ray exposures when monitoring for NORM. Alpha and beta particles are harmful once inside the body. Breathing NORM contaminates from dusts should be prevented by wearing respirators with particulate filters. In the case of properly trained occupational NORM workers, air monitoring and analysis may be necessary. These measurements, ALI and DAC, are calculated values based on the dose an average employee working 2,000 hours a year may be exposed to. The current legal limit exposure in the United States is 1 ALI, or 5 rems. A rem, or roentgen equivalent man, is a measurement of absorption of radiation on parts of the body over an extended period of time. A DAC is a concentration of alpha and beta particles that an average working employee is exposed to for 2,000 hours of light work. If an employee is exposed to over 10% of an ALI, 500 mREM, then the employee's dose must be documented under instructions with federal and state regulations.

Regulation

United States

NORM is not federally regulated in the United States. The

Nuclear Regulatory Commission The United States Nuclear Regulatory Commission (NRC) is an independent agency of the United States government tasked with protecting public health and safety related to nuclear energy. Established by the Energy Reorganization Act of 1974, the ...

(NRC) has jurisdiction over a relatively narrow spectrum of radiation, and the Environmental Protection Agency (EPA) has jurisdiction over NORM. Since no federal entity has implemented NORM regulations, NORM is variably regulated by the states.

United Kingdom

In the UK regulation is via the Environmental Permitting (England and Wales) Regulations 2010. This defines two types of NORM activity: *Type 1 NORM industrial activity means: (a) the production and use of thorium, or thorium compounds, and the production of products where thorium is deliberately added; or (b) the production and use of uranium or uranium compounds, and the production of products where uranium is deliberately added * Type 2 NORM industrial activity means: (a) the extraction, production and use of rare earth elements and rare earth element alloys; (b) the mining and processing of ores other than uranium ore; (c) the production of oil and gas; (d) the removal and management of radioactive scales and precipitates from equipment associated with industrial activities; (e) any industrial activity utilising phosphate ore; (f) the manufacture of titanium dioxide pigments; (g) the extraction and refining of zircon and manufacture of zirconium compounds; (h) the production of tin, copper, aluminium, zinc, lead and iron and steel; (i) any activity related to coal mine de-watering plants; (j) china clay extraction; (k) water treatment associated with provision of drinking water; or (l) The remediation of contamination from any type 1 NORM industrial activity or any of the activities listed above. An activity which involves the processing of radionuclides of natural terrestrial or cosmic origin for their radioactive, fissile or fertile properties is not a type 1 NORM industrial activity or a type 2 NORM industrial activity.Guidance to Environmental Permitting (England and Wales) Regulations (EPR) 2010

References

{{Reflist

External links

North Dakota Department of Health

NORM Technology Connection
Interstate Oil and Gas Compact Commission
Radiation Quick Reference Guide

Domestic Nuclear Detection Office The Domestic Nuclear Detection Office (DNDO) is a jointly staffed office established on April 15, 2005 by the United States to improve the nation’s capability to detect and report unauthorized attempts to import, possess, store, develop, or tran ...

Naturally Occurring Radioactive Materials
from the World Nuclear Association
UK guidance on Radioactive Substances Regulation For the Environmental Permitting (England and Wales) Regulations 2010:Defra
Radioactive waste By-products Environmental impact of fossil fuels Environmental impact of mining Water pollution