Example applications radioactive waste

The Applications of Laser-induced Time-resolved Spectroscopic Techniques chapter starts with a short description of laser-induced spectroscopies, which may be used in combination with laser-induced luminescence, namely Breakdown, Raman and Second Harmonic Generation. The chapter contains several examples of the application of laser-based spectroscopies in remote sensing and radiometric sorting of minerals. The proljlem of minerals as geomaterials for radioactive waste storage is also considered. 

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. 

Reverse osmosis has been employed in full scale in many nuclear centers around the world. Permeate after reverse osmosis can be directly discharged to the environment or recycled as service water within nuclear power plant. There are a number of industrial RO applications and facilities in the stage of pilot plants operating for radioactive waste processing. Some examples of installations are presented in Table 30.1. 

Examples of Application of NF for Liquid Radioactive Wastes Processing and Isotopes Separation... 

Historically, a classic example of an evaporation process is the production of table salt. Maple syrup has traditionally been produced by evaporation of sap. Concentration of black liquor from pulp and paper processing constitutes a large-volume present application. Evaporators are also employed in such disparate uses as desalination of seawater, nuclear fuel reprocessing, radioactive waste treatment,preparation of boiler feed waters, and production of sodium hydroxide. They are used to concentrate stillage waste in fermentation processes, waste brines, inorganic salts in fertilizer production, and rinse liquids used in metal finishing, as well as in the production of sugar, vitamin C, caustic soda, dyes, and juice concentrates, and for solvent recovery in pharmaceutical processes. 

The use of glass is not restricted to the cases mentioned above. Among other applications, mention can be made of those in nuclear technology (protection from radiation, immobilization of radioactive waste by fusion into a chemically resistant glass, etc.), in agriculture (as carrier for fertilizers with long-term effects) and a number of possible applications in electronics (cf., for example, the survey paper by McMillan, 1976). A separate chapter is devoted to the so-called glass-ceramics. 

There are many examples of the studies on SLM for nuclear applications in the literature. SLMs were tested for high-level radioactive waste treatment combined with removal of actinides and other fission products from the effluents from nuclear fuel reprocessing plants. The recovery of the species, such as uranium, plutonium, thorium, americium, cerium, europium, strontium, and cesium, was investigated in vari-ons extracting-stripping systems. Selective permeation... 

The review process described in this Safety Guide is valid for nuclear power plants of any age, but may have a wider applicability, for example, to research reactors and radioactive waste management facilities. A PSR is not... 

Because of the anion complexation observed in the solid state, it was proposed that cyclo[8]pyrrole could function as an anion extractant, specifically for sulfate. Sulfate receptors that can act as extractants of this ion are highly desirable because sulfate is a problematic species in the vitrification process that is proposed for the disposal of certain radioactive wastes. The original reported short-chained forms of cyclo[8]pyrrole presented solubility issues, but a newer derivative, octamethyl-octaundecylcyclo[8]pyrrole, 2b, originally developed as a precursor for liquid crystals, proved to be amenable to extraction studies. It was found that 2b was able to selectively extract sulfate in the presence of high levels of nitrate. This cyclo[8]pyrrole was thus able to overcome the so-called Hofmeister bias or the inherent propensity for nitrate to partition before sulfate. While the kinetics are slow—reducing utility in the context of near-term applications—this is the first example where this level of selectivity is seen in a sulfate versus nitrate extraction experiment. ... 

There are very many applications of gamma-ray spectrometry. Having already discussed environmental measurements in Chapter 16, in this chapter I discuss a number which, to me, seem to be of particular interest. Each of them deserves a much broader treatment but time and space limit me to a general introduction. Each of them draws upon the principles developed in previous chapters, the idea being to illustrate how academic, and perhaps theoretical, ideas find their expression in practical uses. As it happens, the examples are related in the sense that in these applications gamma spectrometry could be said to help make ordinary life safer measurements in support of the Comprehensive Test Ban Treaty (CTBT) help to prevent the proliferation of nuclear weapons, waste monitoring helps to ensure that radioactive waste is disposed of properly and safeguards measurements make sure that nuclear material is properly accounted for. 

Potential fusion applications other than electricity production have received some study. For example, radiation and high temperature heat from a fusion reactor could be used to produce hydrogen by the electrolysis or radiolysis of water, which could be employed in the synthesis of portable chemical fuels for transportation or industrial use. The transmutation of radioactive actinide wastes from fission reactors may also be feasible. This idea would utilize the neutrons from a fusion reactor to convert hazardous isotopes into more benign and easier-to-handle species. The practicality of these concepts requires further analysis. 

Sometimes, to achieve a particular objective, the conditions of the correct preparation of cation-exchanged montmorillonites can be neglected. For example, Fe(III)-montmorillonite has been prepared for application in the deep geological repository of high-level nuclear wastes (Manjanna et al. 2009). Acidic pH has been applied, destroying the crystal lattice however, a part of iron(III) ion has been precipitated as oxide and hydroxide, desirable for the sorption of radioactive matter. 

Human health biomonitoring using biomarkers and chemical analyses are used in the following applications (1) Health surveillance of persons who are known to have high occupational or environmental exposures to potentially toxic chemicals. This may include those who work with chemicals, radioactive materials, or biohazards as part of their occupation. Examples include factory workers, chemical industry employees, farmers, health care professionals, nuclear plant employees, and veterans of the Gulf War I. This may also consist of those who are involuntarily exposed to such hazards in their everyday surroundings. Some examples are people living near land fills, factories, hazardous waste sites, or environmental catastrophes such as the Chernobyl... 

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