Radiation Areas

Krishnan K and Vijayalakshmi NR. 2005. Alterations in lipids lipid peroxidation in rats fed with flavonoid rich fraction of banana (Musa paradisiaca) from high background radiation area. Ind J Med Res 122(6) 540-546. 

High radiation area Accessible area where radiation levels could allow an individual to receive a dose equivalent in excess of 0.1 rem (1 mSv) in 1 hour at 30 centimeters from the radiation source or from any surface the radiation penetrates. 

Figure 49 is a simplified diagram of an x-ray proximity printer showing the source, x-ray confinement cavity, mask, and wafer. As discussed previously, it is necessary to design a source with as small a radiating area as possible in order to minimize penumbral shadowing and with a maximum intensity of x-rays to minimize exposure time. Watts and Maldonado have extensively reviewed conventional x-ray sources, and the reader is referred to that work for additional details. 

Workers are removed from radiation areas reducing exposnres. 

The same assumptions apply for gas generation as for heat generation—that the sample is isotropic, that the gas generation rate does not vary with time or location in tne radiation area, and that the sample length is more than twice either of the other dimensions. 

High-radiation areas must be secured carefully (i.e., level greater than 500 rad, radiation absorbed dose in 1 h at a distance of 1 m from the source) by providing proper ventilation and respiratory equipment, which monitors air contamination. It is also recommended that the radioactive material be properly stored with the required control along with posting signs such as ... 

Very high radiation area Airborne radioactive area Labelling of containers... 

Identification of toxic or radiation areas, minimize number of people exposed, degree of exposure... 

Consider the emission of radiation by a differential area element dA of a surface, as shown in Fig. 12-18. Radiation is emitted in all directions into the hemispherical space, and ihe radiation streaming though the surface area dS is proporiional to the solid angle d(o subtended by dS. It is also proportional to ihe radiating area dA as seen by an observer on dS, wluch varies from a maximum of dA when dS is at the top directly above dA (d = 0 ) to a minimum of zero when dS is at the bottom (0 = 90 ). Therefore, the effective ar ea of dA for emission in the direction of B is the projection of dA on a plane normal to 9, which is dA cos 0. Radiation intensity in a given direction is based on a unit area normal to that direction to provide a comnioii basis for the comparison of radiation emitted in different directions. 

Method Type Radiation Area examined Topographic ... 

Radiation area is an area in which an individual could receive from a radiation source a dose equivalent in excess of 5 mrem (0.05 mSv) in 1 h at 30 cm from the source. 

Caution Radiation Area This sign must be posted in radiation areas. 

Personnel monitoring is required when an occupational worker is likely to receive an excess of 10% of the annual dose limit from radiation sources and for individuals entering high or very high radiation areas. Monitoring is accomplished by using film badges or thermoluminiscent dosimeters (TLD). 

Define restricted area, radiation area, high radiation area, and very high radiation area. 

B. Pocket dosimeters provide direct-reading capability that allows the dosimeter to be read at any time while working in a radiation area to get an estimate of the exposure received. The pocket dosimeter shall be read and doses recorded daily in the utilization log. If, at any time, dosimeters read off scale, an emergency situation is considered to exist and the individual s TLD badge and the control badge must be submitted immediately for processing. 

Equipment within the high-radiation area that may experience mechanical or electrical failure or is subject to severe corrosion can be replaced remotely the rest of this equipment is designed for direct maintenance after cleanout and decontamination. 

The counting equipment does not have to be carried to the radiation area. 

To protect personnel, areas where radiation sources are used are marked with certain signs. The definitions of radiation areas and the corresponding signs are as follows. ... 

High radiation area means an area, accessible to individuals, in which radiation levels could result in an individual s receiving a dose equivalent in excess of 1 mSv (100 mrem) in 1 hour at... 

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