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List of orphan source incidents

List of orphan source incidents is a physics 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 List of orphan source incidents rather than just read about it. In short: This is a chronological list of orphan source incidents and accidents. Metric prefixes are used where appropriate: kilo (k), mega (M), giga (G), tera (T).

Key takeaways

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

Reference excerpt

This is a chronological list of orphan source incidents and accidents. Metric prefixes are used where appropriate: kilo (k), mega (M), giga (G), tera (T). Note: As incident reporting has used inconsistent units of measurement, the table below shows conversion factors.

20th century

1960s 1962 – Mexico City – 1962 Mexico City radiation accident in which a boy brought home an unshielded cobalt-60 capsule, radiation from which killed all of the family members but one. January 11, 1963 – Sanlian, Hefei, Anhui, China – A 10 Ci (370 GBq) cobalt-60 source from an industrial seed irradiator was removed from a buried waste repository and taken to a residence by a child. Over the next 5–9 days, six total family members were exposed. Two died and four were injured. May 3, 1968 – La Plata, Argentina – A construction worker at a chemical plant discovered a caesium-137 source and carried it in his pants pocket for 17 hours (right pocket for 7 hours, left pocket for 10 hours). The worker suffered a localized dose of 50–1,700 rad (0.50–17.00 Gy), leading to permanent sterility and the eventual amputation of both legs. 17 workers were exposed to an estimated dose of 40 rad (0.40 Gy). September 18, 1968 – F.R. Germany – An iridium-192 source was mishandled by workers, with one person placing the source in their jacket pocket. Six workers were exposed, with one receiving a 100 rad (1.0 Gy) whole body dose and 4,000–6,000 rad (40–60 Gy) localized dose to their pelvic and thigh regions.

1970s 1971 – Chiba, Japan – a 5.26 Ci (195 GBq) iridium-192 source used for industrial radiography was lost. Six construction workers received doses of 15–130 rem (0.15–1.30 Sv). January 8, 1977 – Sasolburg, Free State, South Africa – a 6.7 Ci (250 GBq) iridium-192 source fell out of its container at a construction site. The radiographer did not notice the loss of the source and left the site. A construction supervisor later picked up the source and placed it in his shirt pocket. He travelled home and placed the source in a cupboard. The source was recognized as lost two days later after workers were shown a replica and it was recovered the same day. The supervisor received a whole body dose of 116 rad (1.16 Gy) and required the amputation of two fingers. His wife and child received doses of 17 rad (0.17 Gy) and 10 rad (0.10 Gy) respectively. May 5, 1978 – Setif, Algeria – A 25 Ci (920 GBq) iridium-192 source fell off a truck during transport. Two children found it and kept it for several days before giving it to their grandmother, who kept it in the kitchen of her home. After 38 days radiation exposure was identified by medical personnel. The grandmother died of radiation injuries, and six members of her family received varying radiation injuries. November 14, 1978 – Kambalda East, Western Australia, Australia – A density gauge containing caesium-137 at the Kambalda Nickel Operations was discovered to be missing. Subsequently, caesium-137 radiation contamination was found at a furnace in Singapore which had accepted scrap metal from the Kambalda operation. After years of negotiation, 119 drums of slightly contaminated waste, holding bricks and sludge from the Singapore furnace, were eventually transported to Western Australia in December 1981 and stored in a bunker at Kambalda. June 5, 1979 – Los Angeles, California, United States – A 28 Ci (1,000 GBq) iridium-192 source was lost on a job site. A worker picked it up and carried it in his pocket for 45 minutes before giving it to a manager. The worker received a 68 rem (0.68 Sv) whole body dose and a 1.5 Mrem (15 kSv) surface dose (60 krem (600 Sv) at 1-cm; ⅜ inch depth) to his buttocks.

1980s October 5, 1982 – Baku, Azerbaijan SSR – An individual carried a caesium-137 source in their pocket, exposing several individuals. Five people died and 13 others were exposed, including one person who suffered ARS. 1982 – Vikhroli, Mumbai, India – An iridium-192 source was lost during transport. A railway worker who found the source suffered significant exposure. December 6, 1983 – Ciudad Juárez, Mexico. Ciudad Juárez cobalt-60 contamination incident. A local resident salvaged materials from a discarded radiation therapy machine containing 6,010 pellets of cobalt-60. The transport of the material led to severe contamination of his truck. Remaining pellets in the scrapyard contaminated another 5,000 metric tonnes of steel to an estimated 300 Ci (11 TBq) of activity. This steel was used to manufacture kitchen and restaurant table legs and rebar, some of which was shipped to the U.S. and Canada. The incident was discovered months later when a truck delivering contaminated building materials to the Los Alamos National Laboratory drove through a radiation monitoring station. Contamination was later measured on roads used to transport the original damaged radiation source. Some pellets were actually found embedded in the roadway. In the state of Sinaloa, 109 houses were condemned due to use of contaminated building material. This incident prompted the U.S. Nuclear Regulatory Commission and Customs Service to install radiation detection equipment at all major border crossings. March 19, 1984 – Casablanca, Morocco – A 16.3 Ci (600 GBq) iridium-192 source was lost and taken home by a laborer, who placed the source on a table in the family bedroom. The source remained in the house for several weeks. Eight people died and three were injured. September 13, 1987 – In the Goiânia accident, scavengers broke open a radiation-therapy machine in an abandoned clinic in Goiânia, Brazil. They sold the 1,375 Ci (50.9 TBq) caesium-137 source as a glowing curiosity. Two hundred and fifty people were contaminated; four died. 1980-1989 - The Kramatorsk radiological accident occurred in Kramatorsk in the Ukrainian SSR. In the late 1970s, a radioactive capsule from a radiation gauge was lost in a quarry; quarried gravel and the capsule were later used to construct the walls of an apartment building. A family consisting of a mother, daughter, and son were all diagnosed with leukemia and died within two years whilst living in the contaminated unit. A father and his two sons moved in shortly afterward. The two sons were also diagnosed and died of leukemia within 2 years. The father pushed for an investigation which led to the discovery of the cesium-137 in the wall.

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with List of orphan source incidents

Start with the simplest possible case. Write down what List of orphan source incidents claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, 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 List of orphan source incidents 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 List of orphan source incidents 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 List of orphan source incidents

In research
List of orphan source incidents appears in physics 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 List of orphan source incidents 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
List of orphan source incidents is common in secondary-school and first-year university syllabi. It links to neighbouring topics Nuclear safety and security, Radiation accidents and incidents, so understanding it makes those chapters shorter.
In everyday life
Look for List of orphan source incidents 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 List of orphan source incidents in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what List of orphan source incidents means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain List of orphan source incidents out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is List of orphan source incidents in simple terms?

This is a chronological list of orphan source incidents and accidents. Metric prefixes are used where appropriate: kilo (k), mega (M), giga (G), tera (T).

Why does List of orphan source incidents matter?

Because it connects several physics 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 List of orphan source incidents?

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 List of orphan source incidents.

Tags

  • Nuclear safety and security
  • Radiation accidents and incidents

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