Radioactive tracer movement

Tracers have been used to label fluids in order to track fluid movement and monitor chemical changes of the injected fluid. Radioactive materials are one class of commonly used tracers. These tracers have several drawbacks. One drawback is that they require special handling because of the danger posed to personnel and the environment. Another drawback is the alteration by the radioactive materials of the natural isotope ratio indigenous to the reservoir— thereby interfering with scientific analysis of the reservoir fluid characteristics. In addition, the half life of radioactive tracers tends to be either too long or too short for practical use. 

Radioactive-tracer log Tracer fluid movements are measured to produce a radioactive-tracer log. This shows the flow of fluid in the casing, tubing and the annulus, and helps to estimate flow rates, leaks, and other points of exit or entry for fluid into the borehole... 

Radioactive unstable atomic nuclei spontaneously emitting particles and energy Radioactive Tracer a radioactive substance used to monitor the movement and behavior of a chemical in biological processes and chemical reactions... 

Using sulfur-35. Sulfur-35 ( S) is a naturally produced radioactive tracer (half-life = 87 d) that can be used to trace the movement of atmospherically derived sulfate in the environment. It is formed in the atmosphere from cosmic ray spallation of " °Ar (Peters, 1959), and deposits on the Earth s surface in precipitation or as dryfall. It can be used both to trace the timescales for movement of atmospheric sulfate through the hydrosphere and, in ideal cases, to trace the movement of young (<1 yr) water. It is an especially useful tracer in regions away from the ocean where sulfate concentrations are relatively low. 

Radioactive tracer An isotope whose movement in the body can be followed because of the radiation it gives off. 

A radioactive tracer is an isotope whose movement in the body can be followed because of the radiation it gives off The radiation can be traced with special equipment held above the body. The pattern produced by the radiation allows a doctor to diagnose any unusual functioning (behavior) of the organ or body part. 

Diffusion in Vegetable Samples as Affected by Moisture Content. (+) Denotes Detectable Movement of tbe Radioactive Tracer, and (-) Denotes No Detectable Movement... 

Radioactive tracers are used for tracking compounds in an organism and for charting the movement of pollutants. Many different isotopes function as medical tracers for imaging organs and processes inside an organism. 

Radioactive tracer techniques have long been used to study particle motion in solids fluidization systems. The advantage of this technique is that the flow field is not disturbed by the measurement facility and, therefore, the measurement of the motion of the tracers represents the actual movement of particles in the system. The tracer particles are usually made of gamma-emitting radioisotopes, and their gamma radiation is measured directly by scintillation detectors. Factors that affect gamma radiation measurement were identified as the characteristics of the radiation source, interactions of gamma rays with matter, the tracer s position relative to the detector, detector efficiency, and dead time of the measurement system. 

Conventional Tracers. A survey of the history of environmental science will show that tracers are important tools for the environmental scientist. They have been used to measure flow rates and dispersion coefficients, to follow the movement of materials through the atmosphere, hydrosphere, and biosphere, and to characterize pollutant sources. Three principal types of tracer have been used in environmental science chemical tracers, such as NaCl, KHSO4, and K2CO3 radioactive tracers, such as H, and Br and fluorescent dyes, such as fluorescein, Rhodamine B, and Rhodamine WT. 

Radiotracer techniques. These involve ipjection of a radioactive tracer into sections of the plant and monitoring its movement with the aid of radiation detectors. Depending on the application, the tracer may be injected either as a pulse or at a constant rate. These techniques are often applied for leak detection and for flow measurement. For instance, a tracer can be injected into the reboiler steam line, and a detector on the process side will determine whether any of it found its way into the process fluid. A case where this technique successfully diagnosed a reboiler leak and measured the rate of leakage has been reported (71). Radiotracer techniques are discussed in detail elsewhere (71, 72, 229, 424). 

Radioactive tracers or coloring agents (such as methylene bine or phenolphthalein) may be used to help to trace the movement of the slurry. 

Aversion of radioactive tracer technique is the activable tracer method. In this, a stable element is added as a tracer to the system under study and the movement or partition of the tracer element is determined afterward by means of the radiation emitted by a radioactive nuclide produced in activation of the element. The activation is usually done by thermal neutrons in a reactor. The basic requirement for the element employed as an activable tracer is that it has an isotope with high activation cross section for the (n,y) reaction, that its concentration is negligibly low in the original system to be studied, and that it is harmless to the system. Br, Sm, Eu, Gd, and Dy are firequently used as activable tracers. Activable tracers are especially suitable for environmental studies, where use of radioactive nuclides is often undesirable or not allowed. 

Makowski, Ye., and G. Grissener. 1967. Quantitative measurement of maritime sediment movement using radioactive tracers, pp. 181-189. In Isotopes in Hydrology. International Atomic Energy Agency, Vienna. Publ. No. STI/PUB/141. (in Russian with English summary.)... 

In medicine, radioactive nuclides, such as the artificial radioactive nuclide cobalt-60, are used to destroy certain types of cancer cells. Many radioactive nuciides are aiso used as radioactive tracers, which are radioactive atoms that are inccrpcrated into substances so that movement of the substances can be foiiowed by radiation detectors. Detection of radiation from radioactive tracers can be used to diagnose cancer and other diseases. 

Nucleonic Monitor movement of sharp pulse of radioactive tracer 50 MPa and higher Special application for subsea pipelines Sensor moves along pipeline or multiple sensors Diagnostics for pipeline performance, And stuck pigging tool or solid buildup/blockages... 

Radiometric detection technology offers high sensitivity and specificity for many appUcations in scientific research. The radioactive emission of the labeled compound is easily detected and does not suffer from interference from endogenous radioactivity in the sample. Because of this unique property, labeled compounds can be used as tracers to study the localization, movement, or transformation of molecules in complex experimental systems. 

Diffusion is followed by tracking the movements of tracer species through the solid to obtain the tracer diffusion coefficient, written as D when the tracer is identical to one of the components of the crystal, and D% when an impurity or foreign atom A is the tracer. Earlier studies made extensive use of radioactive isotopes because the progress... 

The control of the uses of radioactivity, should ensure that the levels in water are below limits derived from the International Commission on Radiological Protection (ICRP) recommendations (ICRP, 1977). Where appropriate, the radioactive content of water is measured by the operator who is authorised to discharge radioactivity, and the results are checked by the appropriate authorising government Departments in addition, tracer experiments to follow water movement are usually carried out by specialist groups with the appropriate measuring equipment. The measurement of the radioactive content of water is carried out by some Water Authorities as a check on trends and natural levels to be expected in the environment (see for example Greenberg et al., 1981). 

Two of antimony s radioactive isotopes are used commercially as tracers. These isotopes are antimony-124 and antimony-125. A tracer is an isotope injected into a living or non-living system. The movement of the isotope can then be followed as it moves through the system. For example, a small amount of antimony-124 could be injected into an oil pipeline. The presence of the isotope can be detected by means of an instrument held above the pipeline. The radiation given off by the isotope causes a light to flash or a sound to occur in the instrument. 

Tritium is popular as a tracer because hydrogen occurs in so many different compounds. For example, suppose a scientist wants to trace the movement of water through soil. The scientist can make up a sample of water made with tritium instead of protium. As that water moves through the soil, its path can be followed by means of the radioactivity the tritium gives off. 

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