Waste disposal radioactive substances

Governs the keeping and use of radioactive substances and the storage and disposal of radioactive waste. 

Caution Handle all radioactive substances according to the radiation safety regulations instituted at each facility approved to handle such materials. Use adequate precautions to protect personal safety and the environment. Dispose of radioactive waste only by following approved guidelines. 

The beneficial use of radiation is one of the best examples of how careful characterization of the hazard is essential for its safe use. A radioactive substance can be safely stored or transported if appropriately contained. Depending on the characteristics of the radioactive material, it can be safely handled by using appropriate shielding and safety precautions. Laboratory workers usually wear special badges that quantify radiation exposure to ensure that predetermined levels of exposure, which are considered safe, are not exceeded. Unfortunately, after more than 50 years, society has not yet been able to design and implement a safe way to dispose of radioactive waste. The hazardous properties of radiation are explored further in a subsequent chapter. 

Unenriched uranium—which contains more than 99 percent of the nonfissionable isotope U-238—undergoes a chain reaction only if it is mixed with a moderator to slow down the neutrons. Uranium in ore is mixed with other substances that impede the reaction and has no moderator to slow down the neutrons, so no chain reaction occurs. 75- Nuclear fission is a poor prospect for powering automobiles primarily because of the massive shielding that would be required to protect the occupants and others from the radioactivity and the problem of radioactive waste disposal. 

Because radium is a radioactive substance, disposal of wastes containing radium is controlled by a number of federal and state regulations (see Chapter 7). Both the EPA and the Nuclear Regulatory Commission have promulgated regulations for land disposal of these wastes detailing containment requirements and permissible exposure levels based on radioactivity. 

Second, waste that contains hazardous substances is classified based on considerations of health risks to the public that arise from waste disposal. The existing classification systems for radioactive and chemical wastes in the United States are not based primarily on considerations of health risks to the public. Rather, classification of hazardous wastes has been based primarily on the source of the waste or the presence of particular hazardous substances. The absence of risk-based waste classifications has had a number of undesirable ramifications ... 

The best example of this is wastes that are classified based solely on the nature of the generating process or facility e.g., high-level radioactive waste, chemical wastes from certain industries), irrespective of the content and concentration of hazardous substances. This results in resources being used unnecessarily on lower-risk situations when they could be better applied to higher-risk situations (hazardous waste disposal or otherwise). For example, billions of dollars have been spent in managing... 

The term risk as used in this Report refers to the probability of harm, combined with the potential severity of that harm. In the context of impacts on human health resulting from disposal of hazardous waste, risk is the probability of a response in an individual or the frequency of a response in a population taking into account (1) the probability of occurrence of processes and events that could result in release of hazardous substances to the environment and the magnitude of such releases, (2) the probability that individuals or populations would be exposed to the hazardous substances released to the environment and the magnitude of such exposures, and (3) the probability that an exposure would produce a response. For example, risk refers to the probability that a member of the public living near a waste disposal site will develop a certain type of cancer as a result of emplacement of hazardous substances at the site. When expressed as a probability, risk is a number between zero and one, without units. In this Report, all values are risks to an individual over a normal lifetime. Risk can be calculated for individual radioactive and chemical substances in waste and for specific pathways by which release and exposure might occur. These component risks can be combined to yield an overall risk that arises from disposal of waste. 

The general concern about limiting off-site releases of hazardous substances is the primary reason why classification of waste based on risks to hypothetical inadvertent intruders at waste disposal sites does not provide a substitute for site-specific risk assessments when determining acceptable disposal practices. Nonetheless, experience with risk assessments at near-surface disposal sites for low-level radioactive waste has indicated that, for most radionuclides, disposal limits that provide adequate protection of future inadvertent intruders should provide adequate protection of the public and the environment at off-site locations as well. Exceptions are expected to occur only in unusual cases of long-lived and highly mobile radionuclides. 

The hazardous waste classification system recommended by NCRP is depicted in Figure 6.1 at the beginning of Section 6. This proposal was developed with two fundamental objectives in mind. First, all wastes that contain radionuclides, hazardous chemicals, or mixtures of the two should be included in the same classification system. A comprehensive hazardous waste classification system should be developed to replace the separate, and quite different, classification systems for radioactive and hazardous chemical wastes, as well as the separate classification systems for radioactive waste that arises from operations of the nuclear fuel cycle and NARM waste. Second, all hazardous wastes should be classified based on considerations of risks to the public that arise from disposition of the material. In this Report, permanent disposal in a permitted facility for hazardous or nonhazardous waste is the assumed disposition of waste containing hazardous substances that has no further use to its present custodian. An important consequence of these two objectives is that the same rules should apply in classifying any waste that contains hazardous substances. 

In an attempt to deal with such unwanted substances as radioactive and chemical wastes, disposal sites are often used that are hydraulically connected with usable water supplies via subsurface transport routes. To manage these wastes effectively, it is desirable to have the capability of predicting the course of solute transport along these connecting routes. 

I Caution. Uranium is a radioactive element and it must be handled with particular care. Fume hoods and other apparatus appropriate for use with radioactive substances must be used. Waste solutions are a source of radioactive contamination, and they must be disposed of properly. 

The use of nuclear energy for power generation and the disposal of nuclear wastes from power plants are controversial social and political issues. It is imperative, therefore, that as a citizen with a stake in these matters, you have some understanding of nuclear reactions and the uses of radioactive substances. 

Clays, like most other natural substances, have some beneficial and some hazardous impacts on the environment. As described in Part 1, clays have a tendeney to adsorb and immobilize ions. This property enables clays to remove ions of pollutants and contaminants from leachates and waste water, thus reducing pollution and contamination. It also facilitates the use of clays in different pollution control measures like carriers of pesticides, liners in waste disposal etc. Clays can also be used in nuclear waste management clay buffers are built from smectite-rich clays into which the containers of radioactive wastes can be safely disposed (Pusch, 2006). 

By comparison with many chemicals, the toxicity of radioactive substances is much better understood. But the subjective fear of radioactivity has to be recognized and responded to. It has, in fact, led to a particular safety philosophy which more and more bears fruit also for the concepts of chemical waste management and disposal. 

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