The concept of disposal of high-level radioactive waste in deep boreholes, and probabilistic performance assessment (PA) of a generic disposal system are described. A series of preliminary PA simulations, conducted to evaluate the possible migration of radionuclides to an accessible environment, are presented. The PA simulations provide estimates of radionuclide releases and mean annual radiati...

In the drive to achieve net-zero carbon emissions, decarbonisation of heating is essential. This can be facilitated by geothermal energy, but drilling wells associated with high risks and costs. The use preexisting (e.g., exhausted hydrocarbon or failed exploration boreholes) offsets this cost while potentially turning liabilities into assets. Newcastle Science Central Deep Geothermal Borehole ...

Characterization of fractured-bedrock aquifers is one of the most difficult problems in hydrogeology. Successful characterization of aquifers at the site scale requires the effective integration of the three basic tools at our disposal: 1) surface geophysical soundings provide full non-destructive coverage of the aquifer volume but are generally ambiguous in interpretation and fail to identify ...

Abstract: Groundwater flow is one of the most important factors for the design of a ground heat exchanger (GHEX) since the thermal environment of the ground around the buried GHEX is significantly affected by heat convection due to the groundwater flow. Several preceding studies have been conducted to develop analytical solutions to the heat transfer model of GHEX with consideration of groundwa...

To examine microbe-mineral interactions in subsurface oceanic crust, we evaluated microbial colonization on crustal minerals that were incubated in borehole fluids for 1 year at the seafloor wellhead of a crustal borehole observatory (IODP Hole U1301A, Juan de Fuca Ridge flank) as compared to an experiment that was not exposed to subsurface crustal fluids (at nearby IODP Hole U1301B). In compar...

The insecticide susceptibility status of one of the Background: Anopheles funestus, main malaria vectors in the Afrotropical regions, remains under-studied due to the difficulty of working with this mosquito species. Collecting their larvae in natural breeding sites, rearing and maintaining them in normal laboratory conditions have been a difficult task. Forced-egg laying technique has been a v...

In recent years, borehole Stoneley wave amplitude and reflectivity have been used for estimating formation permeability based on the strong correlation between Stoneley wave attenuation, reflectivity and formation fluid conductivity. There are other factors, however, that may cause substantial Stoneley attenuation and reflection in a borehole environment. To make better use of Stoneley measurem...

Background:  The insecticide susceptibility status of Anopheles funestus, one of the main malaria vectors in the Afrotropical regions, remains under-studied due to the difficulty of working with this mosquito species. Collecting their larvae in natural breeding sites, rearing and maintaining them in normal laboratory conditions have been a difficult task. Forced-egg laying technique has been a ...

The amplitudes of P and S head waves in a full waveform acoustic log microseismogram are studied numerically as a function of borehole and formation parameters. The technique used is contour integration around the respective branch cuts in the complex wavenumber plane (Tsang and Rader. 1979). The results showed that the P wave amplitUde depends on the Poisson's ratio, but the S wave amplitude d...

In vertical radar profiling (VRP), the receiver antenna is located within a borehole while the transmitter antenna is placed at varying offsets from the borehole. VRP surveys are primarily used to reconstruct subsurface georadar velocities by inverting direct-wave traveltimes. We examine the VRP technique and associated concepts that need to be considered when acquiring, analyzing and interpret...