Environment radioactive waste

Pollution The impairment (reduction) of water quality by agriculture, domestic or industrial wastes (including thermal and radioactive wastes) to such a degree as to hinder any beneficial use of the water or render it offensive to the senses of sight, taste, or smell or when sufficient amounts of waste creates or poses a potential threat to human health or the environment. 

Reduction of cnviromncntal pollution requires lower energy use and new technology to decrease emission of gases such as sulfur dioxide and carbon dioxide, and to prevent toxic fluoride, heavy metal, and radioactive wastes from discharging into the environment. 

Nielson SP, Iosjpe M, Strand P. 1997. Collective doses to man from dumping of radioactive waste in the Arctic Seas. Sci Total Environ 202 135-146. 

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. 

Disposal of spent nuclear fuel and other radioactive wastes in the subsurface and assessment of the hazards associated with the potential release of these contaminants into the environment require knowledge of radionuclide geochemistry. Plutonium (Pu), for example, exhibits complex environmental chemistry understanding the mechanism of Pu oxidation and subsequent reduction, particularly by Mn-bearing minerals, is of major importance for predicting the fate of Pu in the subsurface. 

According to the vendor, a key advantage of the SpinTek system is that the membranes are less likely to foul compared to static membrane systems. This feature results in less downtime for the system. The system also allows continuous operation during changes in influent waste stream characteristics, eliminating downtime for flux recovery. In addition, SpinTek requires a relatively small area for operations. The vendor states that the system is ideal for operation in hostile environments, including high temperature, pH, radioactive waste, chemical solutions, and solvent solutions. 

Experimental investigations of spectroscopic and other physical-chemical properties of actinides are severely hampered by their radioactive decay and radiation which lead to chemical modifications of the systems under study. The diversity of properties of lanthanide and actinide compounds is unique due to the multitude of their valency forms (which can vary over a wide range) and because of the particular importance of relativistic effects. They are, therefore, of great interest, both for fundamental research and for the development of new technologies and materials. The most important practical problems involve storage and processing of radioactive waste and nuclear fuel, as well as pollution of the environment by radioactive waste, where most of the decayed elements are actinides. 

Wood, S. A., van Middlesworth, P., Gibson, P. Ricketts, A. 1997. The mobility of the REE, U, and Th in geological environments in Idaho and their relevance to radioactive waste disposal. Journal of Alloys Compounds, 249, 136-141. 

Banks, D. 1994. The abandonment of the Killingdal sulphide mine, Norway a saga of acid mine drainage and radioactive waste disposal. Mine Water and the Environment, 13, 35-48. 

The work presented here enables us to get a clearer picture of the problems involved in permanent isolation of radioactive wastes from the environment. 

One of the more important factors affecting the isolation of radioactive waste is the rate of release of the radioactivity from the solid waste form to the environment. The most probable mechanism for release and transport of radioactivity from a solid waste form is by leaching of radioactive isotopes with groundwater. The objective of leach-testing various waste forms is to evaluate the rate at which specific hazardous radionuclides migrate from waste if and when the waste form comes in contact with groundwater. In this paper, measurement of leach rates of radioactive waste by a method which incorporates neutron activation is described. 

Field Studies. We have attempted to compare the relative availability of actinides to small mammals living in contaminated environments near ORNL. Shrews, rats and mice have been collected from a 30 year old contaminated floodplain forest ecosystem ( ). Cotton rats (Sigmodon hispidus) have been collected from the banks of a former liquid radioactive waste pond which contains Pu, Am and Cu in sediments and shoreline vegetation. Analyses were performed by isotope dilution mass spectrometry (U, Th and Pu) or by alpha spectrometry (Pu, Am and Cm). 

About one-fifth of our annual exposure to radiation comes from nonnatural sources, primarily medical procedures. Television sets, fallout from nuclear testing, and the coal and nuclear power industries are minor but significant nonnatural sources. Interestingly, the coal industry far outranks the nuclear power industry as a source of radiation. The global combustion of coal annually releases into the atmosphere about 13,000 tons ol radioactive thorium and uranium. Worldwide, the nuclear power industries generate about 10,000 tons of radioactive waste each year. Most of this waste is contained, however, and is not released into the environment. As we explore in Chapter 19, where to bury this contained radioactive waste is a heated issue yet to be resolved. 

In the United States, however, the public perception of nuclear energy is less than favorable. There are formidable disadvantages, including the creation of radioactive wastes and the possibility of an accident that releases radioactive substances into the environment. In rebuttal, advocates point out that we cannot insist that nuclear fission energy be absolutely safe while at the same time accept tanker spills, global warming, acid rain, and coal-miner diseases. 

In general terms, the goal of long-term waste storage is to isolate the radioactive waste from humans and the environment. The prevailing design strategy for waste repositories is that of multiple barriers (Fig. 16.12). 

---