A comparative assessment of the radiological impact of the disposal of spent fuel and vitrified high-level waste

This paper consists of a preliminary comparative assessment of the radiological consequences of the deep geological disposal of high-level wasteforms, focusing on the differences between the performance of spent fuel and vitrified high-level waste in potential repository environments. In order to undertake quantitative assessment calculations, the important mechanisms controlling the degradation of, and radionuclide release from, each of the wasteforms must be modeled. These mechanisms are briefly described and compared. Their relative importance is estimated from the results of a preliminary assessment of the disposal of the waste arising from 1 ton of original uranium fuel. The results indicate that, within the constraints of the available data and in the absence of firm proposals for the development of a site, the risks from the disposal of the two wasteforms are broadly comparable, but that the mechanisms controlling this result are distinctly different.