A5071141896- Radioactive element chemistry and processing
- Geophysical and Geoelectrical Methods
- Geophysical Methods and Applications
- Seismic Waves and Analysis
- Geochemistry and Elemental Analysis
- Radioactive contamination and transfer
- Chemical Synthesis and Characterization
- Groundwater flow and contamination studies
- Graphite, nuclear technology, radiation studies
- Nuclear and radioactivity studies
- Environmental remediation with nanomaterials
- Mineral Processing and Grinding
- Electrochemical Analysis and Applications
- Geochemistry and Geologic Mapping
- Mine drainage and remediation techniques
Sellafield (United Kingdom)
2013-2022
The presence of uranium in groundwater at nuclear sites can be controlled by microbial processes. Here we describe the results from stimulating reduction U(VI) sediment samples obtained a nuclear-licensed site UK. A variety different lithology sediments were selected to represent heterogeneity subsurface underlain glacial outwash deposits and sandstone. natural communities stimulated via addition an acetate/lactate electron donor mix monitored for changes geochemistry molecular ecology. Most...
A full-scale field experiment applying 4D (3D time-lapse) cross-borehole Electrical Resistivity Tomography (ERT) to the monitoring of simulated subsurface leakage was undertaken at a legacy nuclear waste silo Sellafield Site, UK. The constituted first application geoelectrical in support decommissioning work UK licensed site. Images resistivity changes occurring since baseline date prior leaks revealed likely preferential pathways liquor simulant flow vadose zone and upper groundwater...
Groundwater at legacy nuclear facilities around the world is contaminated with radionuclides including strontium-90 and technetium-99, which are often present as co-contaminants. Here we investigated whether biostimulation of indigenous microbial communities by glycerol phosphate can co-treat 90Sr through incorporation into biominerals, 99Tc microbially-induced reduction sediment to form less mobile Tc(IV) phases via reaction reduced species (e.g. Fe(II)). Results showed that 95% Sr was...
Many different approaches have been developed to regularise the time-lapse geoelectrical inverse problem. While their advantages and limitations demonstrated using synthetic models, there few direct comparisons of performance field data. We test four inversion methods (independent inversion, temporal smoothness-constrained 4D spatial smoothness constrained data differences, sequential with constraints on model its changes). focus applicability these automated processing monitoring in near...
At nuclear contaminated sites, microbially-mediated Fe(III) reduction under alkaline conditions opens up the potential for co-treatment of groundwater contaminants 99Tc, though to less mobile Tc(IV) phases, and 90Sr, through increased sorption and/or precipitation promoted at higher pH. In experiments described here, microbial enrichment cultures derived from representative Sellafield sediments were used probe effect on mobility 99Tc Sr (as stable Sr2+ elevated concentrations 90Sr2+...
Iron nanoparticles are a promising new technology to treat contaminated groundwater, particularly as they can be engineered optimise their transport properties. Technetium is common contaminant at nuclear sites and reductively scavenged from groundwater by iron(II). Here we investigated the potential for range of optimised iron remove technetium groundwater/sediment systems. Nano zero-valent Carbo-iron stimulated development anoxic conditions while generating Fe(II) which reduced soluble...
The behavior of technetium at ultra-trace (<10−10 mol l−1) concentrations in bioreducing sediment column experiments was investigated using 99mTc γ-camera imaging. Four flowing columns were biostimulated for varying periods time, acetate as an electron donor, such that on the day imaging they represented oxic, early metal-reducing, Fe(III)-reducing and sulfate-reducing conditions. Prior to imaging, spiked with 9.6 MBq 99mTc(VII)O4−, which is relevant 99Tc mass observed nuclear facilities,...
The high-yield fission products 99Tc and 90Sr are found as problematic radioactive contaminants in groundwater at nuclear sites. Treatment options for radioactively contaminated land include bioreduction approaches, this paper explores 99mTc behavior stability under a range of biogeochemical conditions stimulated by electron donor addition methods. Dynamic column experiments with sediment from the Sellafield facility, completed site relevant flow conditions, demonstrated that...
Summary We present results of a laboratory study novel electrical resistivity tomography (ERT) sensor materials, whose performance has been assessed in terms suitability for long-term geoelectrical monitoring. The addressed concerns over the longevity buried ERT sensors required to support nuclear decommissioning at Sellafield Site UK. Electrodes made from three candidate materials and installed bentonite grout were subjected accelerated measurements electrochemical analyses carried out on...
We review the development of Micro-Optical Ring Electrode (MORE) for analysis trans-uranium elements in aqueous mixtures. The MORE is a photo-electrochemical device based on ring microelectrode that uses insulator interior to as light guide. This single exploits unique photophysical and electrochemical properties multiple analytes present mixtures quantify them. Our study aims develop protocol ions uranium, neptunium plutonium, which are most relevant nuclear industry, especially areas...
Summary The reduction of risk and hazard associated with the UK’s civil nuclear legacy is a strategic priority for Nuclear Decommissioning Authority (NDA). A full-scale field trial using 4D ERT has been completed successfully at Magnox Swarf Storage Silos Sellafield Site, which monitored controlled injection experiment. This paper summarises achievements lays out future plans geoelectrical monitoring Sellafield. potential as long-term tool explored, electrode longevity estimates are made...
Summary Results are presented from a 2-year full-scale field trial of Electrical Resistivity Tomography (ERT) monitoring simulated leaks waste storage silo at Sellafield, UK. The included the series injections conductive tracer fluids to simulate leaks, as well an extended period assess fate resulting saline plume. constituted first application ERT subsurface UK nuclear licensed site. work was undertaken evaluate Technology Readiness in terms detecting, spatially characterising and potential...