ContentsPages

1.0Introduction to Radioisotope2

2.0The Technology Radioisotope In Malaysia4

3.0Applications of Radioisotope That Could Be Beneficial to Vietnam10

4.0Impacts Of Radioisotopes to The Quality Of Life On Earth14

5.0Conclusion18

6.0Reference19

1.0

Introduction to Radioisotope

An atomic species is defined by two whole numbers: the number of protons in the nucleus (known as Z, or atomic number) and the total number of protons plus neutrons (known as Z, or mass number).

Isotopes are the atoms in an element that have the same atomic number but a different atomic mass; that is, the same number of protons and thus identical chemical properties, but different numbers of neutrons and consequently different physical properties. Isotopes can be stable or unstable or radioisotopes. In the latter, their nuclei have a special property: they emit energy in the form of ionizing radiation while searching for a more stable configuration.

The atomic number defines the chemical element that the atom belongs to. Thus, regardless of the number of neutrons they have, all atoms whose nuclei have one proton are hydrogen atoms. All of those with eight protons are oxygen atoms, etcetera.

The mass number is the whole number that is closest to the mass (expressed in atomic mass units) of the atom in question. Thus, all the atoms with A = 2 have a mass of approximately 2 mass units; atoms with A = 235 have a mass of approximately 235 atomic mass units.

Isotopes (from the Greek isos = same and tpos = place) are atoms from a same element, whose nuclei have a different number of neutrons and, therefore, differ in mass. That is, they have the same atomic number (Z) but different mass numbers (A).

For instance, carbon is presented in nature as a mix of three isotopes with mass numbers 12, 13 and 14: 12C, 13C and 14C. The global amounts of carbon in each are respectively 98.99%, 1.11% and traces.

Most chemical elements possess more than one isotope, as is the case of tin, the element with the highest number of stable isotopes. Only 21 elements, like beryllium and sodium, have one single natural isotope.Isotopes are also subdivided into stable isotopes (there are less than 300) and unstable or radioactive isotopes (there are around 1,200). The concept of stability is not exact, since there are almost stable isotopes. That is, for some time they are unstable and become stable or turn into other stable isotopes.These are radioactive isotopes, since they have an unstable atomic nucleus (due to the balance between neutrons and protons) and emit energy and particles when it changes to a more stable form. The energy liberated in the form change can be measured with a Geiger counter or with photographic film.

Each radioisotope has a characteristic disintegration or semi-life period. Energy may be liberated mostly in the form of alpha (helium nuclei), beta, (electrons or positrons), or gamma (electromagnetic energy) rays.

Several unstable and artificial radioactive isotopes have medical uses. For instance, a technetium isotope (99mTc) may be used to identify blocked blood vessels. Various natural radioactive isotopes are used to determine chronologies, such as the archeological kind (14C).

Applications of radioisotopes:MedicineDiagnosis and treatment of diseases, sterilization of products frequently used in clinical and surgical environments, etc.

Industry and technologyreview of materials and welding in construction, control of productive processes, research, etc.

AgriculturePlague control, food conservation, etc.

Artrestoration of art objects, verification of historic or artistic objects, etc.

ArcheologyGeological event dating, etc.

ResearchUniverse, industry, medicine, etc.

PharmacologyThe study of the metabolism of drugs before they are authorized for public use

2.0

The Technology Radioisotope In MalaysiaThe unique characteristics of nuclear materials have found application in many areas unrelated to the traditional nuclear fields. In particular, radioisotopes - either naturally or manufactured radioactive material - have found broad application in tools, gauges, and imaging machines. Such equipment has been used by a diverse range of occupations including law enforcement, the oil industry, archeologists, farmers and manufacturers of common consumer products. At the core of these applications is the radioisotope. Although radiation can't be seen, it can still be easily detected with the right instruments. Its penetrating nature and its unique detectability provide the real advantage of this technology.2.1

Industry: Gauging

Radioisotopes are used during manufacturing processes in a number of different ways. One application is in gauging (measuring precisely). Gauging works because radiation loses energy as it passes through substances. This principle can be used to measure the presence or the absence of material between the source and the detector.

The radiation that passes through a material is measured and compared with the radiation that would pass through a required thickness of the material. If more radiation is measured, the material is too thin; if less radiation is measured, the material is too thick. During manufacturing, instruments that are sensitive to the measurements will activate controls to maintain the proper thickness. The advantage in using this form of gauging or measurement is that there is no contact with the material being gauged.Some machines, that manufacture plastic film use radioisotope gauging to measure the thickness of the plastic film. The film runs at high speed between a radioactive source and a detector. The detector signal strength is used to control the plastic film thickness as it is continuously made.

The height of the coal in a hopper can be determined by placing high-energy radioactive sources at various heights along one side with focusing collimators directing beams across the load. Detectors placed opposite the sources register the breaking of the beam and, hence, the level of coal in the hopper. A light beam could not do the same job in a very dusty atmosphere.

When the intensity of radiation from a radioisotope is reduced by matter in the beam, some radiation is scattered back towards the radiation source. The amount of 'backscattered' radiation is related to the amount of material in the beam, and this too can be used to measure characteristics of the material. This principle is used to measure different thicknesses of coatings.2.2

Industry: Gamma-radiography

Another application of radioisotopes in the manufacturing process is called gamma-radiography. This process uses gamma-ray radioisotopes to test materials for flaws such as invisible cracks, defects and occlusions in welds, etc. The advantage of gamma radiography compared to non-nuclear technologies is that gamma radiography can be done thoroughly and non-invasively (one does not have to cut the material open), as well as more rapidly and cheaply. It can even be done continuously as objects pass by on a conveyor belt.

The process is very similar to x-ray radiography in a hospital or x-ray screening of luggage at an airport. The difference is that instead of using x-rays, gamma radiography uses a source that is more penetrating, such as cobalt-60, and that is portable and easy to use. X-ray sets can only be used when electric power is available and when the object to be x-rayed can be taken to the x-ray source and radiographed.

Radioisotopes have the supreme advantage in that they can be taken to the site when an examination is required, and no electric power is needed. All that is needed to produce effective gamma rays is a small pellet of radioactive material in a sealed titanium capsule. The capsule is placed on one side of the object being screened, and some photographic film is placed on the other side.

The gamma rays, like x-rays, pass through the object and create an image on the film. Just as x-rays show a break in a bone, gamma rays show flaws in metal castings or welded joints. The technique allows critical components to be inspected for internal defects without damage and in place.

Because isotopes can be transported easily, gamma radiography is particularly useful in remote areas where, for example, it has been used to check welds in pipelines that carry natural gas or oil. Where a weld has been made, special film is taped over the weld around the outside of the pipe. A machine called a "pipe crawler" carries a shielded radioactive source down the inside of the pipe to the position of the weld.

There, the radioactive source is remotely exposed and a radiographic image of the weld is produced on the film. This film is later developed and examined for signs of flaws in the weld.2.3

Industry: Use of Tracers

Radioisotopes can also be used as tracers not just in medicine, but also in industry. These radiotracers emit gamma rays and/or beta particles that can be detected and measured by a variety of different counters -- either in situ or from samples in labs. By proper analysis the quantity of the tracer can be determined at any point in a pathway through which it is traveling. The tracers used are specific to the use.

For example, one wouldn't want a long-lived tracer to measure pollution in a stream that only took a day to empty into the river. On the other hand, one might be interested in longer-lived species if one was also interested in how plants along the way took in the fluids and in what happened to them as a consequence. The activity selected would also depend on the decay time because you still need to take accurate measurements later in time. Then from a combination of the original characteristics of the tracer and its dilution and elapsed time and quantity of the measured sample, the absolute origin and time-of-passage are easily identifiable. The radiotracers can be applied in different ways:

Mixing efficiency of industrial blenders can be measured: radiotracers are added to various solutions that are to be mixed together to allow the manufacturer to determine when his mixture has reached uniformity.Radiotracers are used to trace down sources of pollution. For example, if one injects a known amount of radioactive tracer at a source of pollution, its pathway downstream can be identified. In this way, it might be found that the industrial plant was the culprit for pollution washed ashore miles away, or (equally likely) that that particular pollutant came from a different source. Similarly, looking at soil washed into streams, it would be possible to determine which farmer (or even which cows) where the culprits by using different tracers. In the old days a colored dye might be used as an indicator, but no accurate measurements could be taken.

Small leaks can be detected in complex systems such as power station heat exchangers or oil pipelines in a refinery.Flow rates of liquids and gases in pipelines can be measured accurately, as can the flow rates of large rivers.The extent of termite infestation in a structure can be found by feeding the insects radioactive wood substitute, then measuring the extent of the radioactivity spread by the insects. This measurement can be made without damaging any structure as the radiation is easily detected through building materials.

Using tracers, research is conducted to examine the impact of human activities. The age of water obtained from underground bores can be estimated from the level of naturally occurring radioisotopes in the water. This information can indicate if groundwater is being used faster than it is being replenished. Tracer radioactive fallout from nuclear weapons' testing in the 1950s and 1960s is now being used to measure soil movement and degradation. This is assuming greater importance in environmental studies of the impact of agriculture.

Radioisotopes are used to test material parts and products such as metals, tire rubber, and engine oil for wear. Radioisotopes are added to these products, and then with the use of sensitive radiation detectors, the location and amount of wear of these products is determined. These tests help the manufacturer to produce the best quality and most reliable products.

In agricultural laboratories, radioisotopes are used to determine how plants take up nutritional materials or fertilizers to improve the efficiency. In the past, the improvement of plant species took several plant generation times as those with good characteristics (say, disease resistance, or nutritional value, or smell -- in herbs) were weeded out and propagated in favor of those with poor characteristics. Now by use of radioactive labeling, it is possible to shorten the time considerably and even arrange that a plant be generated with all the desirable characteristics (both disease resistance and oil flavor in the case of the peppermint plant).2.4

Industry: Consumer ProductsRadioisotopes are used in a number of consumer products, so much so, that probably not a day goes by, without you having run into some consumer product that relied on some radioisotope application. Indeed they are now vital to industry. Here are a few examples:Smoke detectorsa smoke detector contains a small amount of americium-241 in the sensing unit that triggers the alarm when there is smoke

Soft drink bottlesradioisotopes are used to measure and control how much soda there is in soft drink bottles

Shrink wrap film/plastic insulation on wiresthe plastic is shrunk by radiation instead of using heat, which damages the insulation

2.5

Agriculture: Crop Improvement

Plant breeding requires genetic variation of useful traits for crop improvement. Different types of radiation can be used to induce mutations to develop desired mutants line that are resistant to disease, are of higher quality, allow earlier ripening, and produce a higher yield. An initial attempt to induce mutations in plants was demonstrated by American Scientist L.J. Stadler in 1930 using X-rays. Later on, gamma and neutron radiation were employed as ionizing radiations. This technique of utilizing radiation energy for inducing mutation in plants has been widely used to obtain desired or improved characters in number of plant varieties. It offers the possibility of inducing desired characters that either cannot be found in nature or have been lost during evolution. A proper selection of mutant varieties can lead to improved quality and productivity.

During last two decades, radiation-induced mutations have increasingly contributed to the improvement of crop plant varieties and it has become an established part of plant breeding methods. Radiation induced mutation experiments are showing promising results for improvement of cultivated crop varieties in many countries. Bhabha Atomic Research Centre (BARC) has developed number of high yielding varieties of tur, green gram, black gram, groundnut, jute and rice by using radiation energy for inducing mutation (Sood et al., 2010). Crop varieties developed by using induced mutations have been found valuable by many national authorities so they have been released and approved for commercial production.

Most of the groundnut and black gram grown in India are from mutant varieties developed at BARC. There are many similar successful mutants in use in other countries, for example, high yielding mutant barleys which can utilize higher doses of fertilizer for increased grain production. Improved pearl millet line showing resistance to downy mildew disease was developed using irradiation treatment in India and is now grown over an area of several million hectares.2.5

Medical UsesThe medical industry uses radioisotopes as a tracer to find tumors, and it's a component of chemotherapy. Commercial uses would be nuclear reactor power plants (the obvious), smoke detectors use radioactive isotopes inside them, and the mars rovers carry nuclear thermal batteries on them.

Nuclear medicine uses radiation to provide diagnostic information about the functioning of a person's specific organs, or to treat them. Diagnostic procedures using radioisotopes are now routine.

Radiotherapy can be used to treat some medical conditions, especially cancer, using radiation to weaken or destroy particular targeted cells. Tens of millions of nuclear medicine procedures are performed each year, and demand for radioisotopes is increasing rapidly. Sterilisation of medical equipment is also an important use of radioisotopes.3.0Applications of Radioisotope That Could Be Beneficial to Vietnam

Vietnam is a country that much depends on her agriculture. Hence, the applications of radioisotope will be preferred. In facts, the medical level of this country is considered low that need helps of the radioisotope to lower the death rate.

3.1

Plant nutrition studiesFertilizers are very expensive and their efficient use is of great importance to reduce the production cost of agricultural crops. It is essential that a maximum amount of fertilizer used during cultivation finds its way into the plant and that the minimum is lost. Radioisotopes are very useful in estimating the amount of phosphorus and nitrogen available in the soil. This estimation helps in determining the amount of phosphate and nitrogen fertilizers that should be applied to soil. Fertilizers labelled with radioactive isotopes such as phosphorus-32 and nitrogen-15 have been used to study the uptake, retention and utilization of fertilizers. Excessive use of fertilizers effects biodiversity and damages the environment. These isotopes provide a means to determine about amount of fertilizer taken and lost to the environment by the plant (Harderson, 1990). Nitrogen-15 also helps in assessment of nitrogen fixed by plants from the atmosphere under field conditions. IAEA develops and transfers techniques that use radioactive isotopes for measuring the nutrient uptake from various fertilizer sources with an aim to achieve higher and more stable grain yields by optimizing the uptake of nutrients from applied fertilizers (Zapata and Hera, 1995). Only small amount of fertilizer applied to the soil is taken up by the crop. The rest either remains in the soil or is lost through several processes. FAO and IAEA have jointly conducted several research programmes for the efficient use of radioactive isotopes for fertilizer management practices in important agricultural crops like wheat, rice and maize (Hera, 1995). Study of soil characteristics is extremely valuable in devising effective methods of farming. Radioactive isotopes can be used as tags to monitor uptake and use of essential nutrients by plants from soil (IAEA, 1996). This technique allows scientists to measure the exact nutrient and water requirements of crop in particular conditions. A major factor in successful crop production is the presence of an adequate water supply. Nuclear moisture density gauges can monitor and determine the moisture content of soil so indicates the exact irrigation needs of a particular area. Nuclear science and technology have greatly facilitated such investigations and are now being widely used in soil plant nutrition research to make the most efficient use of limited water sources. Ionizing radiation is also used to sterilize the soil and there is a good deal of current interest in the use of radiation for the eradication of microorganisms in the soil which causes diseases and are harmful to plant life.

3.2

Insect pest management

Insect pests are responsible for significant reduction in production of agricultural crops throughout the world (Alphey, 2007). Insect pests are serious threat to agricultural productivity. They not only reduce crop yields but also transmit disease to cultivated crops. Radiolabel pesticides were used to monitor the persistence of their residues in food items, soil, ground water and environment. These studies can help to trace and minimize the side effects of pesticides and insecticides. There are concerns that continuous uses of pesticides have negative impacts on the environment and it also results into development of resistance against pesticides in many insect species (ANBP, 2005). Moreover, pesticides not only kill target species but also many other beneficial pest species responsible for maintaining natural ecological balance in the crop fields. IAEA is using nuclear science to develop environmentally friendly alternatives for pest control. FAO and IAEA division jointly sponsors projects and conducts research on control of insects using ionizing radiations. They have placed considerable emphasis on the Sterile Insect Technique (SIT) proposed by Knipling in 1955 (Knipling, 1955). This technique relies on application of ionizing radiation as a means to effectively sterilize male insects without affecting their ability to function in the field and successfully mate with wild female insects. This technique involves release of large numbers of sterile male insects of the target species in the field crop. Sterile male insects compete with the regular male population during sexual reproduction and the eggs produced from their mating are infertile so they produce no offspring (Morrison et al., 2010). It is highly specific form of "birth control which reduces and eliminates the insect population after two or three generations. It has been effectively utilized in elimination of Mediterranean fruit fly from US, Mexico and Chile and screw worm infestation in the US and Mexico (Klassen and Curtis, 2005; Wyss, 2000; Lindquist et al., 1992). It has been successfully used to eradicate several insect pests of agricultural significance throughout the world.

3.3

Radioisotopes in MedicineNuclear medicine uses radiation to provide diagnostic information about the functioning of a person's specific organs, or to treat them. Diagnostic procedures using radioisotopes are now routine.

Radiotherapy can be used to treat some medical conditions, especially cancer, using radiation to weaken or destroy particular targeted cells.

Tens of millions of nuclear medicine procedures are performed each year, and demand for radioisotopes is increasing rapidly. Sterilisation of medical equipment is also an important use of radioisotopes.This is a branch of medicine that uses radiation to provide information about the functioning of a person's specific organs or to treat disease. In most cases, the information is used by physicians to make a quick, accurate diagnosis of the patient's illness. The thyroid, bones, heart, liver and many other organs can be easily imaged, and disorders in their function revealed. In some cases radiation can be used to treat diseased organs, or tumours. Five Nobel Laureates have been intimately involved with the use of radioactive tracers in medicine.

Over 10,000 hospitals worldwide use radioisotopes in medicine, and about 90% of the procedures are for diagnosis. The most common radioisotope used in diagnosis is technetium-99, with some 40 million procedures per year (16.7 million in USA in 2012, 550,000 in Australia), accounting for 80% of all nuclear medicine procedures worldwide.

In developed countries (26% of world population) the frequency of diagnostic nuclear medicine is 1.9% per year, and the frequency of therapy with radioisotopes is about one tenth of this. In the USA there are over 20 million nuclear medicine procedures per year among 311 million people, and in Europe about 10 million among 500 million people. In Australia there are about 560,000 per year among 21 million people, 470,000 of these using reactor isotopes. The use of radiopharmaceuticals in diagnosis is growing at over 10% per year.

The global radioisotope market was valued at $4.8 billion in 2012, with medical radioisotopes accounting for about 80% of this, and is poised to reach about $8 billion by 2017. North America is the dominant market for diagnostic radioisotopes with close to half of the market share, while Europe accounts for about 20%.

Nuclear medicine was developed in the 1950s by physicians with an endocrine emphasis, initially using iodine-131 to diagnose and then treat thyroid disease. In recent years specialists have also come from radiology, as dual CT/PET procedures have become established.

Computed X-ray tomography (CT) scans and nuclear medicine contribute 36% of the total radiation exposure and 75% of the medical exposure to the US population, according to a US National Council on Radiation Protection & Measurements report in 2009. The report showed that Americans average total yearly radiation exposure had increased from 3.6 millisievert to 6.2 mSv per year since the early 1980s, due to medical-related procedures. (Industrial radiation exposure, including that from nuclear power plants, is less than 0.1% of overall public radiation exposure.)

With the help of the radioisotope, then I believe that the death rate

4.0

Impacts Of Radioisotopes to The Quality Of Life On Earth

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 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 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.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.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.

5.0

ConclusionRadioisotopes can be manufactured in several ways. The most common is by neutron activation in a nuclear reactor. This involves the capture of a neutron by the nucleus of an atom resulting in an excess of neutrons (neutron rich). Some radioisotopes are manufactured in a cyclotron in which protons are introduced to the nucleus resulting in a deficiency of neutrons (proton rich).

The nucleus of a radioisotope usually becomes stable by emitting an alpha and/or beta particle (or positron). These particles may be accompanied by the emission of energy in the form of electromagnetic radiation known as gamma rays. This process is known as radioactive decay.

Radioactive products which are used in medicine are referred to as radiopharmaceuticals.

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.6.0

Reference

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.

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 .1