Community Research and Development Information Service - CORDIS

Abstract

UK Nirex Ltd is currently investigating a site near Sellafield, Cumbria, United Kingdom to determine whether it would be a suitable location for a deep repository for solid intermediate-level and some low-level radioactive waste. This report presents the results of a study to determine the hydrogeological properties of the 'blocks' of fractured volcanic rock (part of the Borrowdale volcanic group BVG) that occur between 'flowing zones' in the deep boreholes. The hydraulic testing programme clearly demonstrated that significant groundwater flow into the borehole only takes place through a limited number of 'flowing zones'. These observations support the hydrogeological conceptual model which envisages a hierarchical structure to the hydrogeological properties of the BVG, with the properties of the fractured rock between the flowing zones being distinct from the properties of the networks of flowing zones themselves. Fracture-network modelling using the NAPSAC computer program concludes that the blocks of BVG between the flowing zones are of very low effective hydraulic conductivity. Groundwater flow in the BVG is therefore expected to occur predominantly through the flowing zones. The magnitude of such flows will depend on the hydraulic properties of the flowing zones and on the way in which they are connected.

Additional information

Authors: ARMITAGE P, AEA Technology, Harwell Laboratory, Didcot, Oxon (GB);HOLTON D, AEA Technology, Harwell Laboratory, Didcot, Oxon (GB);JEFFERIES N L, AEA Technology, Harwell Laboratory, Didcot, Oxon (GB);MYATT B J, AEA Technology, Harwell Laboratory, Didcot, Oxon (GB);WILCOCK P M, AEA Technology, Harwell Laboratory, Didcot, Oxon (GB)
Bibliographic Reference: EUR 16870 EN (1996) 117pp., FS, ECU 13.50
Availability: Available from the (2)
ISBN: ISBN 92-827-6703-5
Record Number: 199610791 / Last updated on: 1996-08-30
Category: PUBLICATION
Original language: en
Available languages: en