Hazardous wastes burial methods

In the past, landfills have been the preferred method of waste tyre disposal because burial eliminates the fire hazard associated with above-ground storage, as well as the unsightliness of tyre piles. However, problems with this method have become increasingly apparent. Because of their composition, tyres are neither decomposable, nor can they easily be compacted (Blumenthal 1993). Therefore, tyres occupy large volumes of landfills, contributing to the already prevalent problem of landfill crowding. 

Procedures for the solidification and stabilization of inorganic compounds from mixed waste (using concrete or epoxy resin) to meet federal land ban restrictions have been outlined (40 CFR 268). This method may also abate the waste s chemical hazard and render a chemical-radioactive waste a radioactive waste. For example, waste lead citrate and uranyl acetate mixtures from electron microscopy can be solidified with port-land cement, which may be accepted for burial at a low-level radioactive waste site. 

What has been done thus far, of course, is simply an assessment of the potential hazard of the isotopes in the high-level waste, i.e., the number of fatal cancers that would be induced if all the waste considered were ingested by a large human population. To convert this into a realistic estimate of the hazard which would actually arise in practice, one has to estimate the probability that the active material will be ingested, given the methods of disposal which are proposed. We are required to estimate the transfer rate, or fraction of the waste which will be transferred from its burial site to be ingested by humans. The transfer rate can then be multiplied by the values shown in Fig. 12.16 to obtain the expected cancer fatalities per yr by integration over time one can then derive the total number of eventual fatalities per GWe yr. 

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