Dr. Jonathon Turner, Nuclear Waste Services
This talk discusses how understanding of geological features, events and processes relevant to the UK will be used to select a suitable site for a Geological Disposal Facility (GDF) for the UK’s longer-lived and higher activity radioactive wastes. What are the properties and processes that need to be understood and taken into account in determining ‘suitability’, and how will a GDF be engineered to match and evolve with the properties of the surrounding geological environment.
The UK GDF Programme benefits considerably from lessons learned from deep geological disposal programmes in other countries, many of which are further ahead than in the UK. However the focus of this talk is on the geological environment that we have to work with in England and Wales. I will cover the primary containment and isolation functions of a GDF and a description of how long-term containment and isolation will be provided by means of the multibarrier system of highly integrated engineered barriers working together with the natural rock barrier.
Whatever the characteristics of the geological environment in which a GDF is constructed, it will need to provide a stable cocoon protecting radioactive waste from natural processes such as glaciations and earthquakes, a low-flux groundwater environment, geochemical conditions that minimise degradation of the engineered components of the GDF, and to promote retention of mobilized radionuclides.