The RCF [Rock Characterisation Facility]: geochemical issues. Proof of evidence

Proof of Evidence by an expert witness is presented in support of the case by Friends of the Earth (FOE) against the proposed construction by UK Nirex Ltd of an underground Rock Characterisation Facility (RCF) at a site in the Sellafield area. The RCF is part of an investigation by Nirex into a suitable site for an underground repository for the disposal of radioactive waste. The objections were raised at a Planning Inquiry in 1995. The importance of the geochemical barrier for a land-based radioactive waste repository is clarified, the geochemical complexities involved in attempting to make predictions about the safety of the repository are discussed, and the role that the proposed RCF could play is assessed. A number of key chemical uncertainties with respect to the RCF have been examined. It is concluded that data acquired from the RCF relating to the geochemical behaviour of important radionuclides will probably not contribute significantly to a rigorous chemical model that can be extrapolated forward in geological time with confidence. (25 references). (UK)