engineering

Naturally occurring radioactive material

Naturally occurring radioactive material is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Naturally occurring radioactive material rather than just read about it. In short: Naturally occurring radioactive materials (NORM) and technologically enhanced naturally occurring radioactive materials (TENORM) consist of materials, usually industrial wastes or by-products enriched with radioactive elements found in the environment, such as uranium, thorium and potassium-40 (a long-lived beta emitter that is part of natural potassium on earth) and any of the products of the decay chains of the fo…

Key takeaways

Naturally occurring radioactive material belongs to engineering; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Naturally occurring radioactive material to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Naturally occurring radioactive material from memory before moving on to harder problems.

Reference excerpt

Naturally occurring radioactive materials (NORM) and technologically enhanced naturally occurring radioactive materials (TENORM) consist of materials, usually industrial wastes or by-products enriched with radioactive elements found in the environment, such as uranium, thorium and potassium-40 (a long-lived beta emitter that is part of natural potassium on earth) and any of the products of the decay chains of the former two, such as radium and radon. Produced water 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 or mining, and through natural processes like leakage of radon 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 may have a higher concentration of radioactive substance than the ore had. By mass perhaps the biggest example of such material is phosphogypsum where radium-sulfate is left with the gypsum that results from treating apatite with sulfuric acid to extract phosphoric acid. 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, 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 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

NORM in construction materials Naturally occurring radioactive materials (NORM) are also present in construction materials, including cement, concrete, bricks, and other building products. A comprehensive research project, HORRADIONEX, quantified the chemical composition and radionuclide activity concentration in these materials, representing a comprehensive study of NORM in the building industry. The dataset, gathered from samples collected between 2020 and 2025 across seven countries (Spain, Italy, China, Morocco, Czechia, France, and Portugal), details major and trace elements by X-ray fluorescence (XRF) and radionuclide activity concentrations (including 238U, 232Th, and 40K) by high-resolution gamma spectrometry.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Naturally occurring radioactive material

Start with the simplest possible case. Write down what Naturally occurring radioactive material claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Naturally occurring radioactive material before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Naturally occurring radioactive material ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Naturally occurring radioactive material

In research: Naturally occurring radioactive material appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Naturally occurring radioactive material in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Naturally occurring radioactive material is common in secondary-school and first-year university syllabi. It links to neighbouring topics By-products, Environmental impact of fossil fuels, Environmental impact of mining, so understanding it makes those chapters shorter.
In everyday life: Look for Naturally occurring radioactive material outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Naturally occurring radioactive material in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Naturally occurring radioactive material means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Naturally occurring radioactive material out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Naturally occurring radioactive material in simple terms?

Why does Naturally occurring radioactive material matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Naturally occurring radioactive material?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Naturally occurring radioactive material.