Published online by Cambridge University Press: 21 February 2011
In the past years a lot of research work has been done in several countries to find a waste form capable of accommodating the wide variety of elements present in commercial high level waste (HLW) and which at the same time, has a higher leaching resistance than the currently favoured high level waste glass. The main problems arising from a product made up of different phases, each of them taking up a certain fraction of the HLW-elements into solid solution, are
1) the necessity of very intimate mixing of the HLW-elements and the inert additives because otherwise undesired highly leachable phases might be formed;
2) the detrimental effect transmutation of the radioactive elements will most probably have on the crystal structure in which they are present. Fracturing and loss of the low solubility of the products are likely to occur.