Skip to main content
Select Source:

Radioactive Waste

Radioactive Waste


Radioactive waste (or nuclear waste) is a material deemed no longer useful that has been contaminated by or contains radionuclides. Radionuclides are unstable atoms of an element that decay, or disintegrate spontaneously, emitting energy in the form of radiation. Radioactive waste has been created by humans as a by-product of various endeavors since the discovery of radioactivity in 1896 by Antoine Henri Becquerel. Since World War II, radioactive waste has been created by military weapons production and testing; mining; electrical power generation; medical diagnosis and treatment; consumer product development, manufacturing, and treatment; biological and chemical research; and other industrial uses.

There are approximately five thousand natural and artificial radionuclides that have been identified, each with a different half-life. A half-life is a measure of time required for an amount of radioactive material to decrease by one-half of its initial amount. Half-life values for each known radionuclide are unique. The half-life of a radionuclide can vary from fractions of a second to millions of years. Some examples of radionuclides with a range of different half-lives include sodium-26 (half-life of 1.07 seconds), hydrogen-3 (half-life of 12.3 years), carbon-14 (half-life of 5,730 years), and uranium-238 (half-life of 4.47 billion years). The decay process of a radionuclide is the
mechanism by which it spontaneously releases its excess energy. Typical mechanisms for radioactive decay are alpha, beta, and gamma emission. Alpha decay is a process that is usually associated with heavy atoms, such as uranium-238 and thorium-234, where excess energy is given off with the ejection of two neutrons and two protons from the nucleus. Beta decay involves the ejection of a beta particle, which is the same as an electron, from the nucleus of an excited atom. A common example of a beta-emitter found in radioactive waste is strontium-90. After an alpha or beta decay, the nucleus of an atom is often in an excited state and still has excess energy. Rather than releasing this energy by alpha or beta decay, energy is lost by gamma emissiona pulse of electromagnetic radiation from the nucleus of an atom.

Everything on Earth is exposed to radiation. However, exposure to radiation at levels greater than natural background radiation can be hazardous. Exposure to certain high levels of radiation, such as that from high-level radioactive waste, can even cause death. Radiation exposure can also cause cancer, birth defects, and other abnormalities, depending on the time of exposure, amount of radiation, and the decay mechanism. High-level radioactive waste from nuclear reactors can be hazardous for thousands of years. Radioactive waste can be categorized by its source or point of origin. Because of this, the governments of many nations have developed waste classification systems to regulate the management of radioactive waste within their borders. The proper treatment, storage, and disposal of radioactive waste are prescribed based on the waste classification system defined in a nation's laws, rules, and regulations. The table outlines common categories of radioactive waste.


Radioactive Waste Description

Radioactive waste can vary greatly in its physical and chemical form. It can be a solid, liquid, gas, or even something in between, such as sludge. Any given radioactive waste can be primarily water, soil, paper, plastic, metal, ash, glass, ceramic, or a mixture of many different physical forms. The chemical form of radioactive waste can vary as well. Radioactive waste can contain radionuclides of very light elements, such as radioactive hydrogen (tritium), or of very heavy elements, such as uranium. Radioactive waste is classified as high, intermediate, or low level. Depending on the radionuclides contained in it, a waste can remain radioactive from seconds to minutes, or even for millions of years.


Radioactive Waste Management

Radioactive waste management includes the possession, transportation, handling, storage, and ultimate disposal of waste. The safe management of radioactive waste is necessary to protect public health. If handled improperly, potential exposures of humans to high-level radioactive waste can be dangerous, even deadly. Some radioactive wastes such as certain types of transuranic waste can cause biological effects in humans only if the radionuclides contained in the waste are directly inhaled or ingested. Most low-level radioactive wastes can be handled by humans without any measurable biological effects. Nevertheless, good handling practices of all radioactive materials and waste should be the goal to provide optimum protection to humans and the environment. There have been historic practices associated with the use of radioactive material where workers were unaware of potential risks. The radium watch dial painters of the 1920s illustrate the health effects that can be associated with improper handling practices. The painters experienced high occurrences of cancer of the larynx and tongue due to ingestion of radium.

The transportation of radioactive waste can occur via roadway, aircraft, ship/barge, and rail. The classification and physical size of radioactive waste dictate the method of transport, the packaging required, and the labeling necessary to allow for the shipment of a specific waste. There are international transportation requirements for radioactive waste, as well as more specific regulations in individual countries.


Radioactive Waste Disposal

Various methods to manage and dispose of radioactive waste have been considered. Proposed management and disposal methods have included the

common categories of radioactive waste
waste category description of waste category common sources of waste common radionuclides in waste and their half-life (y=years)
high-level radioactive waste highly radioactive material that is deemed a waste that requires special precautions by humans, including remote handling and use of shielding; also includes spent fuel and waste resulting from the reprocessing of used fuel partially used fuel from nuclear power reactors; liquid waste from the reprocessing of spent fuel taking place outside the united states strontium-90 half-life: 29.78 y cesium-137 half-life: 30.07 y
transuranic waste material that is deemed a waste that contains radionuclides with an atomic number greater than that of uranium (92) weapons-production waste included mixed transuranic waste plutonium-238 half-life: 87.7 y americium-241 half-life: 432.7 y
mixed waste material that is deemed a waste that contains both radionuclides and a characteristic or listed hazardous waste weapons-production waste and some research wastes plutonium-239 half-life: 24,100 y plutonium-241 half-life: 14.4 y
naturally occurring radioactive material (norm) waste material that is deemed a waste that contains radionuclides that are present on earth without any human interaction scale buildup on pipe walls that carry petroleum products radium-226 half-life: 1,599 y radium-228 half-life: 5.76 y
uranium or thorium mill tailings waste the tailings material created as a by-product by the extraction of uranium or thorium from natural ore formations production exclusively at the site of milling for rare earth extraction radium-226 half-life: 1,599 ythorium-230 half-life: 75,400 y
low-level radioactive waste (llrw)(and intermediate waste outside u.s.) material that is deemed a waste that generally has been contaminated by or contains short-lived radionuclides or longer-lived radionuclides in relatively low concentrations. low-level radioactive waste is further segregated into classes (see below) industrial trash from nuclear power plants; medical, research, and academic trash such as paper, plastic, and glass hydrogen-3 half-life:12.32 ycobalt-60 half-life: 5.27 y
class a: lowest level of llrw, generally decays in 100 y    
class b: moderate level of llrw, generally decay in 300 y    
class c: special controls required for this high level of llrw, including shielding/barriers that must isolate for 500 y    
greater than class c: exceed the class c limits and cannot be disposed in llrw facilities; must be disposed with high-level radioactive waste    
exempt material or very low activity waste material that is deemed a waste that contains trace concentrations of short half-life radionuclides that are considered below regulatory concern various medical procedures iodine-131half-life: 8.027 days

following scenarios: shallow land burial; engineered disposal vaults; vertical shafts drilled into granite, salt, basalt, or volcanic rock; disposal cavities mined into specific rock formations such as salt; deeper-earth disposal into the submantle layer; above-ground isolation in engineered, concrete structures; recycling and reuse of waste material; radionuclide transmutation into nonradioactive material; ocean and seabed disposal; ice-sheet disposal; isolation disposal on a remote island; and even disposal in space.

Most of the civilian high-level radioactive waste throughout the world is currently being stored at nuclear power reactor sites. The spent nuclear fuel generated from the 103 operating civilian power reactors in the United States is currently being stored on-site at the point of generation. In Europe, prior to on-site storage, spent fuel is first sent to either the Sellafield site in the United Kingdom or the La Hague site in France to be reprocessed in order to recover usable fuel. No reprocessing of commercial spent fuel is being conducted in the United States. In the United States, spent fuel and other high-level radioactive waste awaits the construction of a central, permanent repository. It is currently stored in spent fuel pools or, in some cases, in dry casks. Spent fuel pools are water-filled, lead-lined chambers that are adjacent to reactors on civilian power reactor sites. Dry-cask storage has become necessary in some cases where the on-site spent fuel pools have reached capacity. The Office of Civilian Radioactive Waste Management at the U.S. Department of Energy (DOE) is charged with developing this federal repository. Amid local opposition, Yucca Mountain, Nevada, is presently under study to evaluate its suitability as a central repository for all U.S. high-level radioactive waste. The Yucca Mountain site has been officially designated by President George W. Bush and Congress for full-scale studies. There has been further emphasis placed on the security of spent fuel, and in general on nuclear reactor sites following the September 11, 2001, terrorist attacks. Nuclear reactor sites that store spent fuel have been identified as possible terrorist targets and, therefore, have been subject to heightened security and debate over potential vulnerabilities. France, Germany, the United Kingdom, and Japan also have plans to develop centralized repositories for high-level radioactive waste at various times in the future.

Transuranic waste generated by the DOE has an operational final repository. The Waste Isolation Pilot Project located near Carlsbad, New Mexico, accepts transuranic waste and mixed transuranic waste (i.e., transuranic waste that also has a hazardous waste component) from federal facilities throughout the United States. This facility is comprised of disposal cavities mined into a salt formation some 2,150 feet underground.

The disposal method used in the 1960s and 1970s for low-level radioactive waste was shallow land burial in earthen trenches. The infiltration of water into these trenches resulted in the migration or movement of certain radionuclides into surrounding soil and groundwater. To respond to such problems, engineered disposal units have been developed to replace shallow land burial, utilizing enhanced cover systems to reduce the potential for water infiltration. The trial-and-error nature of early radioactive waste disposal sites has rendered new facility development a slow and cautious process.


Historical Perspective

The first commercial site for the disposal of low-level radioactive waste was opened in Beatty, Nevada, in 1962. Within the next ten years, five more sites opened in the United States: in Washington, Illinois, South Carolina, New York, and Kentucky. Private companies operated these sites on land leased from state governments. Prior to 1979, the DOE routinely used commercial sites for the disposal of federal waste.

Migration problems at commercial disposal sites in the United States were first discovered in the late 1960s. Four of the six commercial low-level radioactive waste disposal sites in the United States closed. Three of the four sites that closed developed leaks due to erosion by surface water, subsidence on tops of trenches, or buried waste immersed in water. Several of these locations became federal Superfund sites due to radionuclides migrating beyond the disposal trenches, complicated by the presence of hazardous waste within the same facilities.

The historical problems experienced with commercial radioactive waste disposal in the United States resulted in the development of new regulatory requirements for site selection, construction parameters, operating practices, and waste-acceptance criteria at future disposal sites. A new U.S. disposal regulation, Title 10, Code of Federal Regulations, Part 61, "Licensing Requirements for Land Disposal of Radioactive Wastes" was introduced in 1982. This regulation outlines the requirements necessary to ensure public health, safety, and the long-term protection of the environment. Since the development of this new regulation in the United States, only one site, in Clive, Utah, has been licensed and opened for disposal of low-level radioactive waste.


Summary

Radioactive waste is being generated in the United States and throughout the world as a result of research, mining, electricity production, nuclear weapons production, and medical uses. There are many possible beneficial activities due to the use of radioactive material. Laws, rules, and regulations are made on a global scale to help ensure the safe handling of radioactive waste to protect human and environmental health. However, the question of the safe final deposition of all radioactive waste generated worldwide is still problematic.

see also Cleanup; Energy, Nuclear; Superfund; Waste, Transportation of; Yucca Mountain.

Bibliography

league of women voters education fund. (1993). the nuclear waste primer. new york: lyons & burford, publishers.

murray, raymond l. (1994). understanding radioactive waste, 4th edition. columbus, oh: battelle press.

parrington, josef r.; knox, harold d.; breneman, susan l.; baum, edward m.; and feiner, frank. (1996). nuclides and isotopes, 15th edition. san jose, ca: general electric company.


internet resources

international atomic energy agency. "world atom." available from http://www.iaea.or.at/worldatom.

u.s. department of energy, office of civilian radioactive waste management. "the yucca mountain project." available from http://www.ymp.gov.

u.s. nuclear regulatory commission. "radioactive waste." available from http://www.nrc.gov/waste.html.

waste link directory. "guide to radioactive waste." available from http://www.radwaste.org/general.htm.

Susan M. Jablonski

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Radioactive Waste." Pollution A to Z. . Encyclopedia.com. 27 Jul. 2017 <http://www.encyclopedia.com>.

"Radioactive Waste." Pollution A to Z. . Encyclopedia.com. (July 27, 2017). http://www.encyclopedia.com/environment/educational-magazines/radioactive-waste

"Radioactive Waste." Pollution A to Z. . Retrieved July 27, 2017 from Encyclopedia.com: http://www.encyclopedia.com/environment/educational-magazines/radioactive-waste

radioactive waste

radioactive waste (nuclear waste) Any solid, liquid, or gaseous waste material that contains radionuclides (radioactive atomic nuclei). These wastes are produced in the mining and processing of radioactive ores, the normal running of nuclear power stations and other reactors, the manufacture of nuclear weapons, and in hospitals and research laboratories. Because high-level radioactive wastes can be extremely dangerous to all living matter and because they may contain radionuclides having half-lives of many thousands of years, their disposal has to be controlled with great stringency.

High-level waste (e.g. spent nuclear fuel) requires to be cooled artificially and is therefore stored for several decades by its producers before it can be disposed of. Intermediate-level waste (e.g. processing plant sludge and reactor components) is solidified, mixed with concrete, packed in steel drums, and stored in special sites at power stations before being buried in concrete chambers in deep mines or below the seabed. Low-level waste (e.g. solids or liquids lightly contaminated by radioactive substances) is disposed of in steel drums in special sites in concrete-lined trenches. In the UK, a company (Nirex Ltd) was set up by the nuclear industry and the government in 1988 to handle the disposal of low-level nuclear waste, which is disposed of at an underground site at Driggs in Cumbria. There are also nuclear reprocessing plants at Dounreay (Scotland) and Sellafield in Cumbria. Formerly, low- and intermediate-level wastes were disposed of in the Atlantic deeps, in steel drums cast in concrete, but this practice was banned by international agreement in 1983.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"radioactive waste." A Dictionary of Biology. . Encyclopedia.com. 27 Jul. 2017 <http://www.encyclopedia.com>.

"radioactive waste." A Dictionary of Biology. . Encyclopedia.com. (July 27, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/radioactive-waste-1

"radioactive waste." A Dictionary of Biology. . Retrieved July 27, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/radioactive-waste-1

radioactive waste

radioactive waste, material containing the unusable radioactive byproducts of the scientific, military, and industrial applications of nuclear energy. Since its radioactivity presents a serious health hazard (see radiation sickness), disposing of such material is a great problem. Methods of disposal include dumping concrete-encased containers filled with radioactive waste in the ocean and burying the waste underground in old salt mines. In 1996 the United States opened a waste processing plant in Aiken, S.C. at the Savannah River nuclear-weapons complex. The waste will be converted into cylinders of radioactive glass, which will then be encased in steel containers that will be stored in an underground concrete vault. While the glass will still be radioactive, it will no longer be possible for the waste to leak into the soil, and there will be no possibility of a chemical explosion such as the one that occurred in the Soviet Union in the late 1950s. The United States has also agreed to accept about 20 tons of waste from research reactors in 41 countries. The spent nuclear fuel, supplied by the United States for medical and research purposes, includes about 5 tons of highly enriched uranium that could be extracted and used to produce nuclear weapons.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"radioactive waste." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 27 Jul. 2017 <http://www.encyclopedia.com>.

"radioactive waste." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (July 27, 2017). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/radioactive-waste

"radioactive waste." The Columbia Encyclopedia, 6th ed.. . Retrieved July 27, 2017 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/radioactive-waste

radioactive waste

radioactive waste Any discarded substance that is radioactive. Wastes are classified as high-, intermediate-, or low-level according to their level of radioactivity. Low-level waste includes clothing and materials which have been used when handling radioactive sources, e.g. in hospitals. It can be safely buried in trenches 9 m deep beneath a covering of 2 m of clay; no alpha or beta radiation could penetrate the clay cover. Intermediate- and high-level wastes are mainly from the fission process in nuclear power stations or from military waste. High-level waste is hot and intensely radioactive. It is stored, usually in ponds of water, for up to 50 years, during which time it cools and its short-lived isotopes decay until it can be classed as intermediate-level. It can then be incorporated in a borosilicate glass or synthetic rock (a synrock), sealed in a container which corrodes at a known rate, and stored in a secure surface or underground facility. After 500 to 1000 years the radioactivity will have decayed sufficiently for the waste to emit no more radiation than many naturally occurring rocks.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"radioactive waste." A Dictionary of Earth Sciences. . Encyclopedia.com. 27 Jul. 2017 <http://www.encyclopedia.com>.

"radioactive waste." A Dictionary of Earth Sciences. . Encyclopedia.com. (July 27, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/radioactive-waste

"radioactive waste." A Dictionary of Earth Sciences. . Retrieved July 27, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/radioactive-waste

radioactive waste

radioactive waste Substances from nuclear processes which are contaminated and not reusable. Low-level waste includes clothing and materials which have been used when handling radioactive sources (e.g. in hospitals and research laboratories). High-level waste is mainly from the fission process in nuclear power stations or from military waste. The high level of radioactivity is caused by short-lived isotopes; their decay leads to lower levels of radioactivity, but from longer-lived isotopes with half lives of up to one million years (although, in most cases, their emissions fall to levels approximately equal to those of natural background radiation after about 500 years and it is not necessary to safeguard them for periods longer than this). During the first phase such waste is stored in corrosion-resistant containers, but the long-term requirement is to find geologically stable repositories so that any leakage will not return to the surface.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"radioactive waste." A Dictionary of Ecology. . Encyclopedia.com. 27 Jul. 2017 <http://www.encyclopedia.com>.

"radioactive waste." A Dictionary of Ecology. . Encyclopedia.com. (July 27, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/radioactive-waste-0

"radioactive waste." A Dictionary of Ecology. . Retrieved July 27, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/radioactive-waste-0