Radiation assessment

A brief examination of Thbles 5.1 and 5.2 shows many chemicals that are common in the environment. In contrast to the relatively extensive assessment of human exposure to ionizing radiation, assessment of the extent of human exposures to these and other chemicals is fragmentary. Because there are some 6,000,000 known chemicals (NAS/NRC,... 

Electric Power Research Institute (EPRI) BWR radiation assessment and control program. 

V. D. McGinniss, "Radiation Curing State-of-the-Art Assessment," Report prepared for the Electric Power Research Institute, Palo Alto, Calif.,... 

The half-hves, y-ray energies, and y-ray emission probabiUties given ia Table 15 are what is needed if the amount of a radioisotope present ia a sample is to be measured. However, there are other uses of radionucHdes where additional data concerning the decay are needed. If a radionucHde is to be iajected or implanted in vivo it is necessary to have data on all of the radiations produced to be able to assess the impact on the ceU stmcture. Table 16 gives samples of the data that can be useful ia this latter case. Such information can be obtained from some of the references above. There are also computer codes that can use the decay data from the ENSDF database to produce this type of information for any radionucHde, eg, RAD LIST (21). 

Conduct a risk assessment to any employee and other persons to identify measures needed to restrict exposure to ionizing radiation and to assess magnitude of risk including identifiable accidents. 

Critical to hazard characterization is the identification of hazards and the assessment of possible worker exposure. This can be accomplished in a variety of ways. As described before, one commonly used technique is a JHA with project teams that include the worker. The information collected is used by the SSHO and the radiation control officer to develop an appropriate hazard control and protection strategy. 

A fireball s radiation hazard can be assessed by two factors its diameter (either as a function of time or original amount of fuel) and combustion duration. Fireball models presented by Lihou and Maund (1982), Roberts (1982), and others start with a hypothetical, premixed sphere of fuel and air (in some cases, oxidant) at ambient temperature. Because the molar volume of any gas at standard conditions... 

The reader should note tliat since many risk assessments have been conducted on the basis of fatal effects, there are also uncertainties on precisely what constitutes a fatal dose of thennal radiation, blast effect, or a toxic chemical. Where it is desired to estimate injuries as well as fatalities, tlie consequence calculation can be repeated using lower intensities of exposure leading to injury rather titan dcatli. In addition, if the adverse healtli effect (e.g. associated with a chemical release) is delayed, the cause may not be obvious. Tliis applies to both chronic and acute emissions and exposures. 

The quantitative assessment of the degree of crystallite orientation by x-ray examination is not free of ambiguity. From a comparative analysis [23] in which results obtained from the consideration of (105) and from three different variations of equatorial reflection were compared, the conclusion was that the first procedure can lead to underrated results, i.e., to the underestimation of the orientation. However, it can be assumed that this does not result from an incorrect procedure, but from ignoring the fact that the adjacent (105) reflex can overlap. The absence of the plate effect of the orientation is characteristic of the orientation of crystallites in PET fibers. The evidence of this absence is the nearly identical azimuthal intensity distributions of the diffracted radiation in the reflexes originating from different families of lattice planes. The lack of the plate effect of orientation in the case of PET fiber stretching has to do with the rod mechanism of the crystallite orientation. 

Infrared Methods Commercial instrumentation for recording infrared radiation has been available for some years and has been explored by the electrical power industry in the UK for assessing corrosion in boiler tubes at power-station shut-down. An external heal source is played onto the outside of boiler tubes at the same time as cold water is circulated inside the tubes. Hot spots due to poor heat conductivity caused by excessive corrosion product indicated areas of high corrosion. 

The methods dependent upon measurement of an electrical property, and those based upon determination of the extent to which radiation is absorbed or upon assessment of the intensity of emitted radiation, all require the use of a suitable instrument, e.g. polarograph, spectrophotometer, etc., and in consequence such methods are referred to as instrumental methods . Instrumental methods are usually much faster than purely chemical procedures, they are normally applicable at concentrations far too small to be amenable to determination by classical methods, and they find wide application in industry. In most cases a microcomputer can be interfaced to the instrument so that absorption curves, polarograms, titration curves, etc., can be plotted automatically, and in fact, by the incorporation of appropriate servo-mechanisms, the whole analytical process may, in suitable cases, be completely automated. 

Ton-molecule reactions are of great interest and importance in all areas of kinetics where ions are involved in the chemistry of the system. Astrophysics, aeronomy, plasmas, and radiation chemistry are examples of such systems in which ion chemistry plays a dominant role. Mass spectrometry provides the technique of choice for studying ion-neutral reactions, and the phenomena of ion-molecule reactions are of great intrinsic interest to mass spectrometry. However, equal emphasis is deservedly placed on measuring reaction rates for application to other systems. Furthermore, the energy dependence of ion-molecule reaction rates is of fundamental importance in assessing the validity of current theories of ion-molecule reaction rates. Both the practical problem of deducing rate parameters valid for other systems and the desire to provide input to theoretical studies of ion-molecule reactions have served as stimuli for the present work. 

General medical devices are the responsibility of the Center for Devices and Radiological Health (CDRH). The CDRH is also responsible for assessing the safety of non-medical radiation-emitting products such as televisions, microwaves and mobile telephones. 

Although in this chapter we have focused on the potential effects of increased UV-B radiation on the Antarctic marine ecosystem, our results also have bearing on efforts to describe the effects of UV radiation on global marine productivity. However, here again, considerable uncertainties still remain in assessing the effects of ozone depletion on global production. Several authors have predicted a... 

This chapter summarizes climate projections presented by the recent Fourth Assessment Report (AR4) of the IPCC, both for the global scale and for the so-called European and Mediterranean region. Besides the IPCC projections, other results regarding the Mediterranean area will be reviewed as well. The emphasis will be mostly placed on temperature and precipitation projections, while other variables, such as wind, solar radiation, or sea level, will not be commented in depth. Some attention will be paid to methodologies used to develop projections, and the corresponding uncertainties will be commented. In general, projections will be given for the end of the current century. 

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