Vitrified hillforts as anthropogenic analogues for nuclear waste glasses – project planning and initiation

Abstract

Nuclear waste must be deposited in such a manner that it does not cause significant impact on theenvironment or human health. In some cases, the integrity of the repositories will need to sustain fortens to hundreds of thousands of years. In order to ensure such containment, nuclear waste is frequentlyconverted into a very durable glass. It is fundamentally difficult, however, to assure the validity ofsuch containment based on short-term tests alone. To date, some anthropogenic and natural volcanicglasses have been investigated for this purpose. However, glasses produced by ancient cultures for thepurpose of joining rocks in stonewalls have not yet been utilised in spite of the fact that they might offersignificant insight into the long-term durability of glasses in natural environments. Therefore, a projectis being initiated with the scope of obtaining samples and characterising their environment, as well asto investigate them using a suite of advanced materials characterisation techniques. It will be analysedhow the hillfort glasses may have been prepared, and to what extent they have altered under in-situconditions. The ultimate goals are to obtain a better understanding of the alteration behaviour of nuclearwaste glasses and its compositional dependence, and thus to improve and validate models for nuclearwaste glass corrosion. The paper deals with project planning and initiation, and also presents some earlyfindings on fusion of amphibolite and on the process for joining the granite stones in the hillfort walls.Keywords: ageing, amphibolite, analogue, anthropogenic, Broborg, glass, hillfort, hill-fort, leaching,long-lived, nuclear, rampart, waste.