Sealed source

SEALED SOURCE A soui ce Containing any radioactive substance whose structure is such as to prevent, under normal conditions of use, any dispersion of radioactive substances into the envu onment, but it does not include any radioactive substance inside a nuclear reactor or any nuclear fuel element. 

Wherever practicable, store radioactive substances in sealed, properly labelled containers. Check for leaks periodically (e.g. 2-yearly intervals) and maintain records of stocks including sealed sources (e.g. for 2 years). 

SC-40 Biological Aspects of Radiation Protection Criteria SC-41 Radiation Resulting from Nuclear Power Generation SC-42 Industrial Applications of X Rays and Sealed Sources SC-44 Radiation Associated with Medical Examinations SC-45 Radiation Received by Radiation Employees SC-46 Operational Radiation Safety... 

Staff preparing radiopharmaceuticals to be administered for nuclear medicine diagnostic and therapeutic procedures and handling sealed sources for brachytherapy use protective blocks to shield the head and trunk. For these workers, a single personal monitor is located on the trunk. ... 

HMSO (1969) The Ionising Radiation (sealed sources) Regulations (Stationery Office). 

According to official regulations, solid standard sources are generally submitted to classical tests of non-contamination by wiping or by immersion, as required. However, in view of the meteorological quality required, some standards being brittle and of low level activity, these tests are not performed in order to avoid any alteration of the standards or of their accuracies. On the other hand, the sealed sources are submitted to strict tests. 

An alternative explanation, which we refer to as pressure-inhibited charge, is that downward hydrocarbon migration from sealing source rocks ceases as the pressure of the underlying stratigraphically contiguous reservoir approaches the pore-pressure of the seal. This process is consistent with capillary theory. 

Figure 15.10 Diffraction diagrams of a high pressure modification of bismuth. The lower diagram shows diffraction data recorded with a conventional sealed source, the upper one data measured with synchrotron radiation (unpublished results).

Medical use—90Sr as a sealed source in an applicator for treatment of superficial eye conditions NRC 2001 j 10CFR35.4000... 

Gauges, Sources, Static Eliminators Iridium-192, Cesium-137, Cobalt-60, Radium-226, neutrons, Americium-241, Polonium-210 Greater than about 4 TBq Sealed sources, and if leaking, surface contamination. 

Check Sources. The following isotopes have been used by the military as check sources Cobalt-60, Krypton-85, Strontium-90, Barium-133, Cesium-137, Lead-210, Radium-226, Thorium-232, Uranium-238, and Plutonium-239. As such, they are normally found as sealed sources associated with radiation detection instrumentation or in a calibration lab, and would take some serious effort to release to the environment. Sealed sources represent an external exposure hazard only (unless they are physically destroyed). One other item that should be considered with respect to sealed source beta emitters is that they are often associated with lower energy. The other sources are gamma emitters, with the exception of the Am-Be source that produces neutrons. The gamma emitters will expose the whole body externally, as will the neutron source. The sealed sources will be detected in most cases using the AN/PDR-77 with the beta/gamma probe. 

USE Additive in powder metallurgy getter for oxygen and nitrogen in electronic tubes wetting agent for ceramic to metal seals source of pure hydrogen. 

Single-crystal diffractometry under high pressure presents several experimental problems, which generally produce low-quality intensity data, and hence, inferior structural refinement results (Zanazzi 1996, Angel et al. 2001). Generally, diffractometry studies were performed with sealed-source X-ray tubes, synchrotron, or neutron radiation. 

The photoionization detector, one of the oldest GC ionization detectors, has recently received renewed attention because of the novel sealed-source technology developed by Driscoll et al. [125,126] this new detector version has seemingly reduced the earlier difficulties with controlling too many parameters during quantitative measurements. The changes in conductivity, following the photoionization effect, are measured in a confined space (the adjacent detector cell ), while the fate of the generated molecular ions is of no particular concern. 

Sealed-source techniques In these techniques the radioactive source remains within a sealed container. Radiation penetrates the column, and veiriations in the amount transmitted or scattered radiation provide information on the inside of the column. This is analogous to the use of X rays in medicine. 

The sealed-source techniques are the most common radioisotope... 

Radioisotopes commonly used for energy-dispersion analysis are listed in Table 14.3. Sealed sources of all types are now commercially available. The price of a source depends on the cost of the radioisotope and the complexity of the instrument design. 

Food may also be sterilized and preserved by food irradiation. Gamma rays from a sealed source of °Co or Cs are used to kill microorganisms in over 40 countries. This process is less expensive than refrigeration, canning, or additives, and it does not make food radioactive. 

No radioactive materials or sealed source devices are used. 

Fig. 4. 23 Left Carbon plate with sealing. Source-. ZSW. Right Metal plate with sealing. Source Daimler AG...

Under the terms of a broad license, the application usually covers a request to use radioisotopes with atomic numbers from 3 to 83, with individual limits on the quantities held of specific isotopes, and an overall limit of the total quantity of all isotopes held at once. In addition, there should be specific identification of sealed sources held separately by the applicant on the license. 

Radioactive sources are used throughout the world in medicine, industry, agriculture, research and education they are also used in some military applications. Many are in the form of sealed sources with the radioactive materials firmly contained or bound within a suitable capsule or housing. The risks posed by these sources vary widely, depending on such factors as the radionuclides used, the physical and chemical form and the activity. 

The categorization is concerned with sealed sources however, the method can also be used to categorize unsealed radioactive sources, and some examples are included in Appendix I. 

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