Nuclear waste types

Classification of wastes may be according to purpose, distinguishing between defense waste related to military appHcations, and commercial waste related to civiUan appHcations. Classification may also be by the type of waste, ie, mill tailings, high level radioactive waste (HLW), spent fuel, low level radioactive waste (LLW), or transuranic waste (TRU). Alternatively, the radionucHdes and the degree of radioactivity can define the waste. Surveys of nuclear waste management (1,2) and more technical information (3—5) are available. 

Corrosion Resistance. Titanium is immune to corrosion in all naturally occurring environments. It does not corrode in air, even if polluted or moist with ocean spray. It does not corrode in soil and even the deep salt-mine-type environments where nuclear waste might be buried. It does not corrode in any naturally occurring water and most industrial wastewater streams. For these reasons, titanium has been termed the metal for the earth, and 20—30% of consumption is used in corrosion-resistance appHcations (see Corrosion and corrosion inhibitors). 

Usually atoms resulting from nuclear fission arc radioactive. There are also radioactive atoms produced from neutron capture by both U and U. Both types of radioactive atoms remain in the nuclear fuel. It is these radioactive atoms that comprise the nuclear wastes that require disposal in an environmentally acceptable manner. 

The United States has the most radioactive nuclear waste and the most complicated array of waste types. Reprocessing of SNF is also practiced in some countries. Although costly, this practice... 

All the countries that produce nuclear waste have chosen the same alternative for the ultimate disposition of HLW, deep geological isolation, and they did so indepeiideiitly of one another. The United States has the most radioactive nuclear waste and the most complicated array of waste types of any nuclear country. Only in the United States can one find the same economy of scale for waste handling. Thus, it leads the world in most activities aimed at safe isolation. Ill France, Japan, and Great Britain, however, reprocessing is routinely practiced. Those countries reprocess HLW for many other countries. As mentioned above, reprocessing is not currently allowed in the United States. 

Worldwide, there are numerous plasma system designs for treatment of all types of wastes. Economical considerations limit their commercial applications to the most profitable actions. Presently they commercially operate in Switzerland and Germany for low level nuclear waste vitrification, in France and the USA for asbestos waste vitrification, in the USA and Australia for hazardous waste treatment, in Japan and France for municipal fly ash vitrification. The most of installations is working in Japan because there 70% of municipal waste is incinerated and the ash can not be used as landfill. EU Regulations banning the disposal to landfill of toxic and hazardous wastes after year 2002 may cause wider use of plasma waste destruction technology in Europe. 

In the final section of the book, Part V, Water-Waste Interaction, various approaches to describe and predict the interaction between waste and water are presented. This part of the book does not only deal with landfills containing different types of municipal waste forms, but also with different nuclear waste forms. Of special interest are laboratory experiments on waste form corrosion and element speciation in aqueous media that represent realistic disposal... 

Industrial utilization of neptunium has been very limited. The isotope 1 Np has been used as a component in neutron detection instruments. Neptunium is present in significant quantities in spent nuclear reactor fuel and poses a threat to the environment. A group of scientists at the U.S. Geological Survey (Denver, Colorado) has studied the chemical speciation of neptunium (and americium) in ground waters associated with rock types that have been proposed as possible hosts for nuclear waste repositories. See Cleveland reference. 

It has been the underlying theme of this paper that the theoretical approach to solubility and speciation of key radionuclides adopted here can be helpful in identifying the general types of species likely to be dominant in aqueous solutions. At present, these estimates are useful in identifying those radionuclides that require special attention in repository performance assessment studies. However, sophisticated experimental studies are necessary to provide important confirmatory data for nuclides of critical importance to the safe isolation of nuclear waste in a repository in basalt. 

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