Precautions radioactive chemicals

A brief discussion of the relevance of physicochemical principles to hazard identification is given in Chapter 3. Relevant toxic and flammable properties, and summaries of appropriate precautions to cater for them during handling, use and disposal, are provided in Chapters 4 and 5 respectively. Reactive hazards are discussed in Chapter 6. The special problems with cryogenic materials and chemicals under pressure, typified by compressed gases, are dealt with in Chapters 7 and 8. The unique problems associated with radioactive chemicals are described in Chapter 10. 

Radioactive chemicals, See also Chemicals Transportation control measures, See Precautions exposure limits, 393 hazards, 391 monitoring, 393 types, 391... 

When an explosive device is used to disperse radioactive, chemical, or biological materials, the treatment of casualties is more difficult because of the presence of contamination. In this situation, emergency responders could face a life-threatening situation unless appropriate precautions are taken. These precautions include using screening instruments (see Section 6.12) to assess hazard conditions before responding, then selecting the appropriate level of personal protective equipment (see Section 6.7) to provide protection from the hazard. 

Some further details are the following. Film nonideality may be allowed for [192]. There may be a chemical activation barrier to the transfer step from monolayer to subsurface solution and hence also for monolayer formation by adsorption from solution [294-296]. Dissolving rates may be determined with the use of the radioactive labeling technique of Section III-6A, although precautions are necessary [297]. 

The high radioactivity of radium requires special handling techniques and precautions. Its high radioactivity is far more important than any chemical toxicity but from a chemical point of view its hazards are similar to those of barium. 

CHEMICAL KINETICS RADIOACTIVE SUBSTANCES (General Precautions)... 

One of the most common topics asked of those who work with the actinides relates to handling procedures. The radioactive nature of these elements does require the use of special facilities, processes, and precautions. However, working with radioactive elements in subcritical quantities is as safe, if not safer, than handling many of the toxic chemicals found in a typical synthetic laboratory. The primary advantage in handling radioactive material is the ease with which these elements can be detected. Unlike other toxic chemicals, for example, lead, thallium, arsenic, and so on, a simple survey (seconds) with a radiation detector will show if containment of the material has been lost, where it is, and approximately how much is present. With appropriate monitoring, virtually no uptake of radioactive material occurs, and if any personnel contamination does occur, it is quickly detected and treated. 

Tc was the first element to be synthesized artificially, hence its name. It was first detected in 1937 by Perrier and Segre in the products of deuteron bombardment of Mo. All the isotopes of Tc are radioactive but Tc, with a half-hfe of 2.1 x 10 y, is a sufficiently long-lived /3-emitter that it can be handled in standard laboratory equipment with appropriate precautions. It is recovered from fission reactors by solvent extraction and ion-exchange methods. It makes up ca. 6% of fission products from U and so is available in kilogram amounts for macroscopic chemical study. Hot acid solutions... 

Catalysts with a heavy-metal content are an exception to the rule that chemical samples do not usually become radioactive. This radioactivity must be allowed to decay to safe levels before it can be handled without very special apparatus or precautions. To avoid delays whilst waiting for this decay, several cells are run in parallel while one is being measured, another is being treated and a third is being left to decay. This method... 

The specific radioactivity of natural uranium makes it a weak radiological hazard (see Ch. 18). It is also chemically toxic and precautions should be taken against inhaling uranium dust for which the threshold limit is 0.20 mg/m air (about the same as for lead). 

Half-lives as short as millionths of a second and as long as billions of years are known. The half-lives of some radioisotopes are listed in TABLE 21.5. One important feature of half-Uves for nuclear decay is that they are unaffected by external conditions such as temperature, pressure, or state of chemical combination. Unlike toxic chemicals, therefore, radioactive atoms cannot be rendered harmless by chemical reaction or by any other practical treatment. At this point, we can do nothing but allow these nuclei to lose radioactivity at their characteristic rates. In the meantime, we must take precautions to prevent radioisotopes, such as those produced in nuclear power plants (Section 21.7), from entering the environment because of the damage radiation can cause. 

Universal precautions/OSHA regulations for bloodborne pathogens contacts Chemical, radioactive materials, biological toxins spills and releases Corporate institutional generic safety policies/procedures as applicable for ... 

Handle special wastes in any way including radioactive materials, chemical wastes, or contaminated biological materials. AU of these require special handling by specialists and precautions must be taken to ensure that these materials are not accidentally collected by custodians. The custodians should be given awareness training to ensure that they have sufficient knowledge to allow them to recognize these special wastes. 

Nevertheless, there are still justifiable and legal reasons to carry out such opaations in the laboratory when hazards can be reduced safely. Neutralizatiorr, oxidation, reductiorr, and various otho" chemical conversions as well as physical methods of separation and concentration can be applied prudently to many laboratory-scale mixed wastes. However, the dual character of the hazard, chemical and radioactive, requires that additional precautions be exercised. Treatment for the chemical hazard must not create a radioactivity risk for personnel or the environment. For example, vapors or aerosols from a reaction, distillation, or evaporation must not lead to escape of unsafe levels of radioactive materials into the atmosphere. Fume hoods appropriate for such operations should be designed to trap any radioactive effluent. When mixed waste is made chemically safe for disposal into the sanitary sewer, the laboratory must ensure that the radioactivity hazard is below the standards set by the publicly owned treatment works (POTW). Several examples for reducing the hazard of mixed waste are described below ... 

However, Na is very chemically reactive substance, which requires special precautions to be taken when it used as a reactor coolant. Therefore, for improved reactor safety, a secondary Na loop is utilized, which acts as a buffer between the radioactive Na—reactor coolant in the primary loop and the water/steam in the third loop—a steam Rankine power cycle. 

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