Transport of 14C and Uranium in the Carrizo Aquifer of South Texas, a Natural Analog of Radionuclide Migration

1983 ◽  
Vol 26 ◽  
Author(s):  
Robert W. Andrews ◽  
F. J. Pearson
Keyword(s):  
Ground Water ◽  
Water Flow ◽  
South Texas ◽  
Performance Assessments ◽  
Ground Water Flow ◽  
Radionuclide Migration ◽  
Natural Analog ◽  
Fraction Distribution ◽  
Nuclide Transport ◽  
Best Fit

ABSTRACTGround-water flow and transport were modeled along a one-dimensional, vertical cross-section of the Carrizo aquifer from its outcrop down gradient for 100 km. Using a constant flux of 14C at the recharge boundary, the 14C mass fraction distribution downgradient was simulated until steady-state was attained. The match between the observed data and simulated results is excellent for a porosity of 35% and a KD of zero. The transport of both 234U and 238U was simulated with varying retardation coefficients. The best fit occurred with a RD of about 30, which corresponds to a KD of 6. The results indicate that modeling may be reliably conducted over time periods and distances of interest in radionuclide transport performance assessments and that regionally averaged hydrologic properties can provide appropriate values for predicting ground-water flow and nuclide transport.

Analytical solution for estimating the influence of a pre-existing ground water flow on a geothermal heat production-injection well system

2011 ◽  
Vol 2 (1) ◽  
pp. 13-17
Author(s):  
I. David ◽  
M. Visescu
Keyword(s):  
Ground Water ◽  
Water Flow ◽  
Geothermal Energy ◽  
Flow Direction ◽  
Energy Resource ◽  
Hot Water ◽  
Injection Well ◽  
Production Well ◽  
Ground Water Flow ◽  
The Earth

Abstract Geothermal energy source is the heat from the Earth, which ranges from the shallow ground (the upper 100 m of the Earth) to the hot water and hot rock which is a few thousand meters beneath the Earth's surface. In both cases the so-called open systems for geothermal energy resource exploitation consist of a groundwater production well to supply heat energy and an injection well to return the cooled water, from the heat pump after the thermal energy transfer, in the underground. In the paper an analytical method for a rapid estimation of the ground water flow direction effect on the coupled production well and injection well system will be proposed. The method will be illustrated with solutions and images for representative flow directions respect to the axis of the production/injection well system.

Sign in / Sign up

Export Citation Format

Share Document