An overview of experimental techniques developed during hydrogeological investigations at Reskajeage Quarry, Cornwall

In fractured rocks, the transport of dissolved radionuclides which may be released from the near-field of a radioactive waste repository will take place dominantly through the three-dimensional network of fractures. Assessments of groundwater flow and radionuclide transport from an underground repository use continuum models, such as NAMMU, to predict radionuclide transport. To complement this approach, water flow and transport in fractured rock is being investigated at a more detailed level, using fracture network modelling. A test side, at Reskajeage Quarry in Cornwall, is currently being used to provide experimental data on flow and transport in fractured rock, to improve confidence in this modelling approach. This report describes the range of experimental techniques that have been used to obtain data on the positions, orientations and hydraulic properties of individual fractures in the slate. Also, brief descriptions of the design of a series of transport tests are given. The results of this work are described in a series of Nirex Safety Series Reports. (author)