Radioactive waste materials

Sediments in the Mississippi River were accidentally contaminated with a low-level radioactive waste material that leaked from a nuclear power plant on the river. Pore water concentrations of radioactive compounds were measured following the spill and found to be 10 g/m over a 2-mm depth. The water contamination was 30% radioactive cesium ( Cs), with a half-life of 30 years, and 70% radioactive cobalt ( °Co), with a half-life of 6 years. Objections by the local residents are preventing clean-up efforts because some professor at the local state university convinced them that dredging the sediments and placing them in a disposal facility downstream would expose the residents to still more radioactivity. The state has decided that the sediments should be capped with 10 cm of clay and needs a quick estimate of the diffusion of radioactive material through the clay cap (Figure E2.8.1). If the drinking water limit (10 g/m ) is reached at mid-depth in the cap, the state will increase its thickness. Will this occur ... 

Over the last twenty years, significant research and development has been performed concerning the ultimate disposal mechanism for radioactive waste. In 1957, the National Academy of Sciences recommended that deep beds of bedded salt be considered as potential locations for the disposal of radioactive waste materials. Following this recommendation a program of research and development was undertaken by the Atomic Energy Commission (AEG) to explore this approach. The high point of this program was the operation of Project Salt Vault in an abandoned salt mine in Lyons, Kansas. 

The recent report by the National Research Council of the National Academy of Sciences entitled "Limitations of Rock Mechanics in Energy Resource Recovery and Development", highlighted some of the problems which must be addressed. The rock strength and other mechanical properties of the media must be understood both under the impact of the thermal pulse represented by the release of heat from decaying radioactive waste materials and the perturbation represented by construction of the mine. The resulting thermal stresses must be understood in developing the layout and the allowable rate of heat generation from the individual canisters. 

However, there are problems. The main problem associated with a nuclear power station is that the reactor produces highly radioactive waste materials. These waste materials are difficult to store and cannot be disposed of very easily. Also, leaks of radioactive material have occurred at various sites throughout the world. Accidents at a small number of nuclear power stations, such as Three Mile Island in the US (1979) and Chernobyl in the Ukraine (1986) have led to a great deal of concern about their safety. More recently, in March 2011 a major nuclear accident happened at the Fukushima nuclear power plant in northern Japan. On this occasion the accident was not caused as a result of the plant itself undergoing a problem, but as a result of an earthquake near Japan that gave rise to a tsunami. This damaged essential... 

Very large quantities of radioactive waste materials are stored at various sites throughout the world.24 The permanent disposal of these wastes involves dividing the material into two parts for treatment. The high-level radioactive species will be absorbed in porous solids and transported to depositories in salt mines or within mountains.25... 

Cell harvesters were developed to capture multiple samples of cells on membrane filters, wash away unincorporated isotopes, and prepare samples for liquid scintillation counting on special equipment developed to process and count multiple samples. Despite miniaturization and improvements in efficiency of this technique, the disadvantages of multiple liquid handling steps and increasing costs for disposal of radioactive waste materials severely limit its usefulness. Although specific applications require measuring DNA synthesis as a marker for cell proliferation, much better choices are available for detecting viable cell number for HTS. 

Besides the analysis of nuclear fuel and of radioactive waste materials, the determination of contamination and enrichment of selected radioactive nuclides, e.g., which is one of the most important environmental indicators of nuclear accidents, Se, Tc, Np, Pu, °Pu and "Am at ultratrace concentration levels, is useful for environmental monitoring of fallout from nuclear weapons testing, nuclear power plants or nuclear accidents. ". Selected application fields for the determination of natural and artificial long-lived radionuclides (LLR) and radionuclides investigated by mass spectrometric techniques are summarized in Tables 9.36 and 9.37, respectively. 

Also gaining acceptance as alternative routes for immobilizing metals are processes such as soil vitrification, and the addition of cement-like (pozzolonic) agents whereby undesirable soil components are entrapped in a vitrified matrix. Vitrification of radioactive waste materials is currently being used as well. Examples of vitrifying media include borosilicate glasses and iron phosphates. Whether a specific vitrification process is chemical or physical in nature is not always clear. Table 10.2 lists the main selection criteria for this application. 

The basalt formulation employs Columbia River-type basalt as a source of silica. Extensive deposits of this basalt underlie the Hanford Reservation so that it is readily available as a raw material for large-scale glass-making. The chemical composition of typical Columbia River basalt is shown in Table VI physical properties of this type of basalt have been determined by Krupka (8) and Leibowitz, Williams, and Chasanov (9). We also note that incorporation of radioactive waste material into melted basalt was studied briefly earlier in Czechoslovakia by Saidl and Ralkova (10). 

This discussion has considered waste in general. Radioactive materials, mentioned several times in the paper, represent a special type of hazardous waste that is often given special consideration. In the authors opinion, such special consideration is not always necessary the principles discussed in this paper apply equally to low-level radioactive-waste materials and some shortlived high-level wastes. 

You probably associate radioactive waste with nuclear reactors, but more than 80 percent of all such waste is generated in hospitals. How can this hazardous waste be dealt with so that it cannot harm living things Most of the radioactive waste material produced at hospitals contains isotopes with short half-lives. That kind of waste can simply be stored until the isotopes have decayed to a safe level. 

It is anticipated that the effectiveness of such storage would be required to last for several hundred thousand years. While the containers are intact, there is no possibility of dispersion of the radioactive contents. However, the question inevitably arises as to the likely consequences if the containers are breached. The subsequent rate of dispersal could well be so slow as to be unmeasurable in a man s lifetime, but could still be significant in relation to the decay time of the radioactive waste materials. There is a possibility that short term experiments could fail to identify processes which might be important in the long-term storage and dispersal. 

For the assay of ACh hydrolysis in whole blood, Winteringham and Disney (1964) introduced a radiometric method with f C]ACh a.s substrate. This is an end point method intended to be used as a field method, Several modifications were later developed with [ 01 ACh or [ H]ACh as substrates (Wilson, 2001), but no radiometric method was widely used. Disposal of radioactive waste material has been noted to be a problem. 

Radioactive Waste - Materials left over from making nuclear energy. Radioactive waste can living organisms if it is not stored safely. 

Records must be maintained by the licensee of disposal of radioactive wastes. Material transferred to a disposal firm is subject to requirements very smularto those covering chemical wastes. The manifesthas specific requirements for the description of the physicaland chemical form of the radioactive materials and the radiation characteristics of the wastes. There are specialists in transporting radioactive waste who normally serve as the intermediary or broker for the generator and disposal facility. 

In this paper, a case study of using fire simulation for fire safety assessment of low level radioactive waste material transporting ship is presented. First, two different fire scenarios are developed from previous fire accidents statistics. Then fire simulation is carried out to evaluate the fire safety performance in each scenario. The main objective of the simulation is to evaluate the extent of damage to the cargo hold carrying hazardous materials due to temperature increase. 

Knowledge of the composition of radioactive waste materials from nuclear equipment (regardless of their phases) is important in choosing a sampling protocol prior to any analytical procedures. 

Radioruthenium enters plants because of direct contamination however, it is usually concentrated in certain water plants, so that its determination is significant, particularly in regions where radioactive waste materials are stored in the sea. Ruthenium determination can be carried out by a simple and direct y-ray spectrometric method. When it satisfies the other conditions, this procedure is rapid and economical. It is difficult to distinguish ° Ru and ° "Ru because of their closely spaced y-lines. 

Heess, W., Schenker, E., Petzold, G., Conrath, A., Diewald, H. P. Dekontamination von Hauptkiihlmittelpumpen mit dem neuen VS-Verfahren. Atomwirtschaft 34, 83-86 (1989) Hoffmann, R., Leidenberger, B. Optimization of measurement techniques for very low level radioactive waste material. Report EUR 13307 EN (1991)... 

Preventing the release of radioactive waste material from on-site storage facilities. 

Media contaminated with radioactive substances, e.g., reactor coolant and radioactive waste materials and,... 

II-ll. Disposable clothing may be relatively costly when the rate of usage is high, and it contributes to the volume of solid radioactive waste material that must be processed. It is appropriate, however, to use disposable clothing when laundering becomes impracticable owing to high levels of contamination. 

The difficulties that waste disposal raised for peaceful atomic development prompted the AEC to devote increased attention to the technical, economic, and public-relations aspects of the problem. One early step it took was to include conditions in its radiation-protection regulations for licensees disposing of small volumes of low-level waste. The regulations allowed discharge of radioactive waste material into public sewerage systems if it was "readily soluble or dispersible in water," did not exceed maximum permissible concentrations after dilution, and did not produce more than one curie per year of radioactivity. The regulations also permitted underground disposal of limited quantities of waste but restricted the number of burials to twelve per year in depths of at least four feet. All other waste-disposal procedures required specific AEC authorization. ... 

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