Common use of Model Formulation Clause in Contracts

Model Formulation. Hydrologic parameters will be derived from the site-scale and regional-scale models. Spatial discretization may be finer than regional-scale models for computational purposes. Hydraulic and thermal properties will be generalized within hydrostratigraphic layers. The model will use a single porosity and permeability within each model element. The model will not include any postulated repository affects and only ambient groundwater temperatures will be considered. The thermal model of the LHG will approximate to the current saturated zone regional interpretation. The thermal model will be steady state for both groundwater flow and thermal transport. The top of the model will be a prescribed hydraulic flux and temperature at the water table. The model will extend to the depth of the Paleozoic carbonate aquifer or deepest thermal log. The bottom of the model will be simulated as a prescribed hydraulic head and a spatially variable thermal flux. The upgradient and downgradient boundaries will be prescribed hydraulic fluxes or hydraulic heads based on the requirements for numerical stability. Both the hydraulic heads and groundwater temperatures will vary with depth. Hydraulic head at the water table surface and any hydraulic heads at depth will be the calibration parameters. The spatial thermal distribution between the upgradient and downgradient boundaries will be the evaluation parameters. Thermal rock properties will be extracted from the project database. Because there is less thermal data at distance from the potential repository location, generalized information will be used in the thermal model. The methodology of Rautman (1995) may be used to assign thermal conductivity unless data that are more explicit are available. University and Community College System of Nevada DOCUMENT CHANGE NOTICE (DCN) page 4 of 5 DCN No. 1 to Document No. SIP-DRI-039, Revision 0, Effective Date: 15FEB05.

Model Formulation. Hydrologic parameters will be derived from the site-scale and regional-scale models. Spatial discretization may be finer than regional-scale models for computational purposes. Hydraulic and thermal properties will be generalized within hydrostratigraphic layers. The model will use a single porosity and permeability within each model element. The model will not include any postulated repository affects and only ambient groundwater temperatures will be considered. The thermal base-case model of the LHG will be approximate to the current saturated zone regional interpretation. The thermal model will be steady state for both groundwater flow and thermal transport. The top of the model will be a prescribed hydraulic flux and temperature at the water table. The model will extend to the depth of the Paleozoic carbonate aquifer or deepest thermal log. The bottom of the model will be simulated as a prescribed hydraulic head and a spatially variable thermal flux. The upgradient and downgradient boundaries will be prescribed hydraulic fluxes or hydraulic heads based on the requirements for numerical stability. Both the hydraulic heads and groundwater temperatures will vary with depth. Hydraulic head at the water table surface and any hydraulic heads at depth will be the calibration parameters. The spatial thermal distribution between the upgradient and downgradient boundaries will be the evaluation parameters. Thermal rock properties will be extracted from the project database. Because there is less thermal data at distance from the potential repository location, generalized information will be used in the thermal model. The methodology of Rautman (1995) may be used to assign thermal conductivity unless data that are more explicit are available. University and Community College System of Nevada DOCUMENT CHANGE NOTICE (DCN) page 4 of 5 DCN NoThe groundwater modeling code FEHM will be used for the simulations. 1 to Document No. SIPThis software was baselined 28 Jan 2003, as FEHM V2.20, STN/CSCI 10086-DRI-039, Revision 0, Effective Date: 15FEB052.20-00.