980 resultados para Radioactive waste sites


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Many geological formations consist of crystalline rocks that have very low matrix permeability but allow flow through an interconnected network of fractures. Understanding the flow of groundwater through such rocks is important in considering disposal of radioactive waste in underground repositories. A specific area of interest is the conditioning of fracture transmissivities on measured values of pressure in these formations. This is the process where the values of fracture transmissivities in a model are adjusted to obtain a good fit of the calculated pressures to measured pressure values. While there are existing methods to condition transmissivity fields on transmissivity, pressure and flow measurements for a continuous porous medium there is little literature on conditioning fracture networks. Conditioning fracture transmissivities on pressure or flow values is a complex problem because the measurements are not linearly related to the fracture transmissivities and they are also dependent on all the fracture transmissivities in the network. We present a new method for conditioning fracture transmissivities on measured pressure values based on the calculation of certain basis vectors; each basis vector represents the change to the log transmissivity of the fractures in the network that results in a unit increase in the pressure at one measurement point whilst keeping the pressure at the remaining measurement points constant. The fracture transmissivities are updated by adding a linear combination of basis vectors and coefficients, where the coefficients are obtained by minimizing an error function. A mathematical summary of the method is given. This algorithm is implemented in the existing finite element code ConnectFlow developed and marketed by Serco Technical Services, which models groundwater flow in a fracture network. Results of the conditioning are shown for a number of simple test problems as well as for a realistic large scale test case.

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The development of activities in the oil and gas sector has been promoting the search for materials more adequate to oilwell cementing operation. In the state of Rio Grande do Norte, the cement sheath integrity tend to fail during steam injection operation which is necessary to increase oil recovery in reservoir with heavy oil. Geopolymer is a material that can be used as alternative cement. It has been used in manufacturing of fireproof compounds, construction of structures and for controlling of toxic or radioactive waste. Latex is widely used in Portland cement slurries and its characteristic is the increase of compressive strength of cement slurries. Sodium Tetraborate is used in dental cement as a retarder. The addition of this additive aim to improve the geopolymeric slurries properties for oilwell cementing operation. The slurries studied are constituted of metakaolinite, potassium silicate, potassium hydroxide, non-ionic latex and sodium tetraborate. The properties evaluated were: viscosity, compressive strength, thickening time, density, fluid loss control, at ambient temperature (27 ºC) and at cement specification temperature. The tests were carried out in accordance to the practical recommendations of the norm API RP 10B. The slurries with sodium tetraborate did not change either their rheological properties or their mechanical properties or their density in relation the slurry with no additive. The increase of the concentration of sodium tetraborate increased the water loss at both temperatures studied. The best result obtained with the addition of sodium tetraborate was thickening time, which was tripled. The addition of latex in the slurries studied diminished their rheological properties and their density, however, at ambient temperature, it increased their compressive strength and it functioned as an accelerator. The increase of latex concentration increased the presence of water and then diminished the density of the slurries and increased the water loss. From the results obtained, it was concluded that sodium tetraborate and non-ionic latex are promising additives for geopolymer slurries to be used in oilwell cementing operation

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This is a list of actions taken against businesses that are not in compliance with environmental regulations including underground storage tanks, hazardous waste, drinking water, water pollution and solid waste. It is broken down by enforcement by various divisions of DHEC including the Bureau of Land and Waste Management, Bureau of Water, Bureau of Air Quality, Bureau of Environmental Health Services and Division of Ocean and Coastal Resource Management.

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This is a list of actions taken against businesses that are not in compliance with environmental regulations including underground storage tanks, hazardous waste, drinking water, water pollution and solid waste. It is broken down by enforcement by various divisions of DHEC including the Bureau of Land and Waste Management, Bureau of Water, Bureau of Air Quality, Bureau of Environmental Health Services and Division of Ocean and Coastal Resource Management.

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This is a list of actions taken against businesses that are not in compliance with environmental regulations including underground storage tanks, hazardous waste, drinking water, water pollution and solid waste. It is broken down by enforcement by various divisions of DHEC including the Bureau of Land and Waste Management, Bureau of Water, Bureau of Air Quality, Bureau of Environmental Health Services and Division of Ocean and Coastal Resource Management.

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This is a list of actions taken against businesses that are not in compliance with environmental regulations including underground storage tanks, hazardous waste, drinking water, water pollution and solid waste. It is broken down by enforcement by various divisions of DHEC including the Bureau of Land and Waste Management, Bureau of Water, Bureau of Air Quality, Bureau of Environmental Health Services and Division of Ocean and Coastal Resource Management.

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This is a list of actions taken against businesses that are not in compliance with environmental regulations including underground storage tanks, hazardous waste, drinking water, water pollution and solid waste. It is broken down by enforcement by various divisions of DHEC including the Bureau of Land and Waste Management, Bureau of Water, Bureau of Air Quality, Bureau of Environmental Health Services and Division of Ocean and Coastal Resource Management.

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This is a list of actions taken against businesses that are not in compliance with environmental regulations including underground storage tanks, hazardous waste, drinking water, water pollution and solid waste. It is broken down by enforcement by various divisions of DHEC including the Bureau of Land and Waste Management, Bureau of Water, Bureau of Air Quality, Bureau of Environmental Health Services and Division of Ocean and Coastal Resource Management.

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This is a list of actions taken against businesses that are not in compliance with environmental regulations including underground storage tanks, hazardous waste, drinking water, water pollution and solid waste. It is broken down by enforcement by various divisions of DHEC including the Bureau of Land and Waste Management, Bureau of Water, Bureau of Air Quality, Bureau of Environmental Health Services and Division of Ocean and Coastal Resource Management.

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This is a list of actions taken against businesses that are not in compliance with environmental regulations including underground storage tanks, hazardous waste, drinking water, water pollution and solid waste. It is broken down by enforcement by various divisions of DHEC including the Bureau of Land and Waste Management, Bureau of Water, Bureau of Air Quality, Bureau of Environmental Health Services and Division of Ocean and Coastal Resource Management.

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This is a list of actions taken against businesses that are not in compliance with environmental regulations including underground storage tanks, hazardous waste, drinking water, water pollution and solid waste. It is broken down by enforcement by various divisions of DHEC including the Bureau of Land and Waste Management, Bureau of Water, Bureau of Air Quality, Bureau of Environmental Health Services and Division of Ocean and Coastal Resource Management.

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This is a list of actions taken against businesses that are not in compliance with environmental regulations including underground storage tanks, hazardous waste, drinking water, water pollution and solid waste. It is broken down by enforcement by various divisions of DHEC including the Bureau of Land and Waste Management, Bureau of Water, Bureau of Air Quality, Bureau of Environmental Health Services and Division of Ocean and Coastal Resource Management.