Uses of Radionuclides

Many radionuclides cannot attain nuclear stability by only one nuclear reaction. Instead, they decay in a series of steps. For any particular decay step, the decaying nuclide is called the parent nuclide, and the product nuclide is the daughter. 

A few such series are known to occur in nature. Two begin with isotopes of uranium, and and one begins with Th. All three of these end with a stable isotope of lead (Z = 82). Table 22-4 outlines in detail the and Th disintegration series, 

Radionuclides have practical uses because they decay at known rates. Some applications make use of the radiation that is continuously emitted by radionuclides. 

The ages of articles of organic origin can be estimated by radiocarbon dating. The radioisotope carbon-14 is produced continuously in the upper atmosphere as nitrogen atoms capture cosmic-ray neutrons. 

Unless otheiwise noteiJ, all content on this page is Cengage Learning, 

Neptunium, plutonium, and all the other synthetic elements having atomic numbers greater than 92 are called the transuranium elements. All transuranium isotopes are radioactive, and some with very short half-lives have only been briefly isolated in extremely small amounts. Some of the bombardments yielding transuranium products use relatively high-mass isotopes as bullets. For example, einsteinium-247 is produced by bombarding uranium-238 with ordinary nitrogen nuclei  

Today there are hundreds, possibly thousands, of uses for synthetic radionuclides. The best known of these are in medicine. People are not usually aware of others, although at times they may be close at hand. For example, do you have a smoke detector in your home Battery-powered smoke detectors use a chip of americium-241, 2 Am. The americium ionizes the air in the detector, which causes a small current to flow through the air. When smoke enters, it breaks the circuit and sets off the alarm, which is powered by a battery (Fig. 20.13). With a half-life of 458 years, the americium doesn t need changing every year as the battery does. 

Artificial radionuclides are used in food preservation (Fig. 20.14). Worldwide, more than 40 classes of foods are irradiated with gamma rays from cobalt-60, 27C0, 

Industrial applications of radionuclides include studies of piston wear and corrosion resistance. Petroleum companies use radionuclides to monitor the progress of some oils through pipelines. The thickness of thin sheets of metal, plastic, and paper is subject to continuous production control through the use of a Geiger counter to measure the amount of radiation that passes through the sheet the thinner the sheet, the more radiation detected by the counter. Quality control laboratories can detect small traces of radioactive elements in a metal part. 

Scientific research is another major application of radionuclides. Chemists use tagged atoms as radioactive tracers to study the mechanism, or series of individual steps, in complicated reactions. For example, by using water containing radioactive oxygen, scientists have determined that the oxygen in the glucose, CgHi20g, formed in photosynthesis 

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Sr, as the strontium ion (Sr2+), is used for pain palliation in patients with metastatic bone disease. The strontium ion is a calcium ion mimic, being taken up in metabolically active bone such as cancer. 89Sr is a therapeutic radionuclide with a half-life of 50.53 days, emitting a 1.49 MeV [3 particle on decay. Several recent reviews discuss the use of radionuclides and their complexes as pain palliation agents in metastatic bone disease.18,212-215... 

Nuclear Medicine—Factors Influencing the Choice and Use of Radionuclides in Diagnosis and Therapy (1982)... 

For the disposal of L IL SL generated at the Swedish NPPs a repository has been established in crystalline rock (as required by the Swedish strategy) 50 m under the seabed outside Forsmark NPP. Following an agreement with the Government and the authorities the repository is also used for radioactive waste from Swedish use of radionuclides in medicine, research and industry that meets the waste acceptance criteria approved by the authorities for the repository. 

Applications include the use of radionuclides in geo- and cosmochemistry, dating by nuclear methods, radioanalysis, the use of radiotracers in chemical research, Mossbauer spectrometry and related methods, the use of radionuclides in the life sciences, in particular in medicine, technical and industrial applications and investigations of the behaviour of natural and man-made radionuclides, in particular actinides and fission products, in the environment (geosphere and biosphere). Dosimetry and radiation protection are considered in the last chapter of the book. 

This chapter focuses on the interactions of radionuclides with geomedia in near-surface low-temperature environments. Due to the limitations on the chapter length, this review will not describe the mineralogy or economic geology of uranium deposits the use of radionuclides as environmental tracers in studies of the atmosphere, hydrosphere, or lithosphere, the nature of the nuclear fuel cycle or processes involved in nuclear weapons production. Likewise, radioactive contamination associated with the use of atomic weapons during World War 11, the contamination of the atmosphere, hydrosphere, or lithosphere related to nuclear weapons testing, and concerns... 

It is the purpose of this book to present the facts about the presence of radionuclides in nature. The use of technology can significantly modify the exposure to natural radiation. Among the human activities which should be considered in this context are (i) the electricity generation by coal-fired power plants, (ii) the use of phosphate fertilizers, and (iii) many consumer products. Man-made radioactivity has found many useful applications in everyday life. The best known are medical applications. The use of radionuclides and radioactivity in diagnosis and treatment of diseases is well established practice. 

Nuclei with Atomic Number Greater Than 83 Detection of Radiation Rates of Decay and Half-Life Disintegration Series Uses of Radionuclides Artificial Transmutations of Elements Nuclear Fission Nuclear Fission Reactors Nuclear Fusion... 

Tell about some uses of radionuclides, including the use of radioactive elements for dating objects... 

The widespread use of radionuclides in the nuclear industry and in other areas of work, means that there is a risk that accidents involving the intake of quite large amounts of one or more radionuclides may occur. Some radionuclides, notably those of lead, strontium, the lanthanides, uranium, thorium, and plutonium are removed quite rapidly from the blood and deposited in bone, where they may be retained for many years. This deposition of non-physiological and potentially toxic... 

The metallic and Ionic cleaning procedures studied by Kern were evaluated by radiotracer methods. This technique requires the use of radionuclide enriched reagents. Recently, a procedure utilizing secondary Ion mass spectrometry (SIMS) has been developed for studying very low levels of contamination on silicon surfaces (18). 

Nuclear and radiochemistry includes accelerator/reactor chemistry for isotope production, nuclear structure, neutrino chemistry, nuclear forensics, and archeometery. Understanding of nuclear and radiochemistry underlies the availability of adequate supplies as well as proper and safe use of radioactivity for energy production or radiomedicine. Twenty percent of electric power in the United States is supplied by nuclear reactors. It is possible that construction of new reactors in the United States will resume within the next decade. Similarly, the use of radionuclides in medicine, research, and industry is predicted to increase. 

The largest single use of radionuclides has been in medical science. If a radioactive compound, such as a radioactivefy labeled amino acid, vitamin, or drug, is administered to a patient, the substance is incorporated in... 

A detailed discussion of the rules for working in radiochemical laboratories and of radiation protection measures falls outside the scope of this chapter a good summary and references for further reading are given elsewhere (Lieser, 1986). When experiments are judiciously planned, hazards of handling reactor- irradiated biological samples are seldom more important than those encountered in other work involving the use of radionuclides. 

To counterbalance these advantages is the disadvantage of the inability to turn off the radiation from radionuclides. This oft requires that the radiation source be well shielded, adding to its weight and cost. An additional drawback to the use of radionuclides is that they have to be r laced after a few half-lives. The seriousness of this disadvantage depends upon the lifetime of the particular nuclide and is uninqmrtant in cases where longlived sources can be used. 

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