TY - RPRT TI - Alligator Rivers Analogue project. Hydrogeological modelling. Final Report - Volume 6 AB - This volume describes hydrogeological modelling carried out as part of the Alligator Rivers Analogue Project. Hydrogeology has played a key integrating role in the Project, largely because water movement is believed to have controlled the evolution of the Koongarra uranium Orebody and therefore affects field observations of all types at all scales. Aquifer testing described uses the concept of transmissivity in its interpretation of aquifer response to pumping. The concept of an aquifer, a layer transmitting significant quantities of water in a mainly horizontal direction, seems hard to accept in an environment as heterogeneous as that at Koongarra. But modelling of aquifers both in one dimension and two dimensionally in plan has contributed significantly to our understanding of the site. A one-dimensional model with three layers (often described as a quasi two dimensional model) was applied to flow between the Fault and Koongarra Creek. Being a transient model, this model was able to show that reverse flows can indeed occur back towards the Fault, but only if there is distributed recharge over the orebody as well as a mechanism for the Fault, or a region near the Fault, to remove water from the simulated cross-section. The model also showed clearly that the response of the three-layered system, consisting of a highly weathered zone, a fractured transmissive zone and a less conductive lower schist zone, is governed mainly by the transmissivity and storage coefficient of the middle layer. The storage coefficient of the higher layer has little effect. A two-dimensional model in plan used a description of anisotropy to show that reverse flows can also occur even without a conducting Fault. Modelling of a three-dimensional region using discrete fractures showed that it is certainly possible to simulate systems like that observed at Koongarra, but that large amounts of data are probably needed to obtain realistic descriptions of the fracture networks. Inverse modelling of aquifer test data has shown that inverse procedures may have some advantages over fitting of analytical type curves, especially in highly heterogeneous environments AU - "Townley, L R" AU - "Trefry, M G" AU - "Barr, A D [CSIRO Div of Water Resources, PO Wembley, WA (Australia)]" AU - "Braumiller, S [Univ of Arizona, Tucson, AZ (United States). Dept of Hydrology and Water Resources]" AU - "Kawanishi, M [Central Research Institute of Electric Power Industry, Abiko-Shi, Chiba-Ken (Japan); and others]" KW - "54 ENVIRONMENTAL SCIENCES" KW - "ANALYTICAL SOLUTION" KW - "COMPUTERIZED SIMULATION" KW - "FLOW MODELS" KW - "GEOLOGIC FAULTS" KW - "GROUND WATER" KW - "HYDRAULIC CONDUCTIVITY" KW - "HYDRAULIC TRANSPORT" KW - "HYDROLOGY" KW - "KOONGARRA DEPOSIT" KW - "NATURAL ANALOGUE" KW - "ONE-DIMENSIONAL CALCULATIONS" KW - "RADIONUCLIDE MIGRATION" KW - "ROCK-FLUID INTERACTIONS" KW - "SENSITIVITY ANALYSIS" KW - "TECTONICS" KW - "THEORETICAL DATA" KW - "THREE-DIMENSIONAL CALCULATIONS" KW - "TWO-DIMENSIONAL CALCULATIONS" DO - https://doi.org/ UR - https://www.osti.gov/etdeweb/servlets/purl/310060 PB - CY - Australia PY - 1992 DA - 1993-12-31 LA - English J2 - [] VL - C1 - Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia) C2 - Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Nuclear Energy Agency, 75 - Paris (France); Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan); Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan); Swedish Nuclear Power Inspectorate, Stockholm (Sweden); Nuclear Regulatory Commission, Washington, DC (United States); Department of the Environment, London (United Kingdom) C3 - INIS-AU-0020; DOE/HMIP/RR-92/076; SKI-TR-92/20/6 C4 - C5 - INIS; OSTI as DE99612870 L3 - Other Information: PBD: 1992 ER -