Community Research and Development Information Service - CORDIS


Cross hole testing between boreholes 2 and 4 at Sellafield was carried out between March and October 1994. Six separate tests were carried out pumping from short intervals containing flowing features in borehole 2 and monitoring the response, through both pumping periods and subsequent recovery in separate isolated zones in both boreholes 2 and 4. The purpose of the testing was to identify the hydraulic characteristics of the rocks of the Borrowdale volcanic group (BVG) within the interval (approximately 100 m) between the two boreholes. Test durations were typically 10 days pumping followed by an equivalent recovery period. Throughout the testing programme test procedures were optimized by onsite data analysis using both radial flow and partial dimension techniques. These results and related uncertainties are discussed in the report and suggest a complex bounded system with a radial flow derived transmissivity in the E-7 to E-8 m{2}s{-1} range. Flow dimensions are in the range 1.5 to 2. Correlation with the understanding of the geology current in 1994 suggests a complex conceptual model with frequent diffuse low permeability connections and occasional barriers in the upper 200 m to 300 m of the BVG and possibly more sparsely connected discrete flowing features below.

Additional information

Authors: SUTTON S, Entect ltd (GB);SOLEY R, Entect ltd (GB);JEFFERY R, Golder Associates (GB);CHACKRABARTY C, Golder Associates (GB);MCLEOD R, United Kingdom NIREX Ltd (GB)
Bibliographic Reference: EUR 16967 EN (1996) 186pp., FS, ECU 33
Availability: Available from the (2)
ISBN: ISBN 92-827-8588-2
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