VITRIFIED FORTS AS ANTHROPOGENIC ANALOGUES FOR ASSESSMENT OF LONG-TERM STABILITY OF VITRIFIED WASTE IN NATURAL ENVIRONMENTS

摘要

The area's natural analogues, vitrified forts, combustion technology, and vitrified waste have been reviewed. The purpose was to identify if investigations of vitrified rock in hill forts might be warranted for assessing the long-term integrity of vitrified waste in natural environments. Wastes that are being vitrified include ash from incineration of domestic waste, contaminated soil and fission products from reprocessing of spent nuclear fuel. It was found that vitrified materials in at least 200 hill forts constitute good anthropogenic analogues to vitrified waste. The compositions vary considerably from site to site and even within one site and may correspond relatively well to the spans of parameters in the various vitrified wastes. Glasses in vitrified forts compare favourably to archaeological artefacts which are soda- and potash-based and consequently have different corrosion behaviours and may weather too quickly. Natural glasses might be too limited in composition variation and are perhaps also too durable. Combustion technology considerations based on quality of heat analyses indicate that at least some of the vitrifications of hill forts were carried out with the specific purpose of achieving strong and durable constructions. This makes it considerably easier to envisage how the vitrifications might have been carried out, and this, in turn, facilitates comparisons between anthropogenic analogues and modern vitrified wastes.