Geoelectrical monitoring of simulated subsurface leakage to support high-hazard nuclear decommissioning at the Sellafield Site, UK

Abstract

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 at the Sellafield Site, UK. The experiment constituted the first application of geoelectrical monitoring in support of decommissioning work at a UK nuclear licensed site. Images of resistivity changes occurring since a baseline date prior to the simulated leaks revealed likely preferential pathways of silo liquor simulant flow in the vadose zone and upper groundwater system. Geophysical evidence was found to be compatible with historic contamination detected in permeable facies in sediment cores retrieved from the ERT boreholes. Results indicate that laterally discontinuous till units forming localized hydraulic barriers substantially affect flow patterns and contaminant transport in the shallow subsurface at Sellafield. We conclude that only geophysical imaging of the kind presented here has the potential to provide the detailed spatial and temporal information at the (sub-)meter scale needed to reduce the uncertainty in models of subsurface processes at nuclear sites.

Three‐Dimensional Time‐Lapse Geoelectrical Monitoring of Water Infiltration in an Experimental Mine Waste Rock Pile

“…Various applications of the ERT method have been presented over the past two decades for: hydrogeological studies (Clément et al, 2014; Hübner et al, 2017, 2015; Nimmer et al, 2008), agricultural applications (Cassiani et al, 2012; Michot et al, 2003; Uhlemann et al, 2016b), ground water resources (Binley et al, 2002; Kuras et al, 2009), tracer and contaminant plume monitoring (Audebert et al, 2016a, 2016b; Koestel et al, 2009, 2008; Kuras et al, 2016, 2014; Power et al, 2014; Rucker et al, 2011; Wilkinson et al, 2010), geotechnical applications (Chambers et al, 2014, 2015; Uhlemann et al, 2016a, 2017) and mining environmental issues (Anterrieu et al, 2010; Dimech, 2018; Dimech et al, 2018, 2017; Intissar, 2009; Power et al, 2018).…”

Accounting for groundwater in future city visions

“…New technologies are emerging to achieve this, e.g. the use of robots to repair underground pipes (Hollingum, 1998) and geophysics for pipe leak detection (Kuras et al, 2016). The extent of groundwater abstraction can be monitored from the induced ground level change, seen in remotely sensed radar interferometry (e.g.…”

Multidisciplinary Characterization of Chlorinated Solvents Contamination and In-Situ Remediation with the Use of the Direct Current Resistivity and Time-Domain Induced Polarization Tomography

“…Frequency based spectral Induced Polarization has been applied to monitoring of stimulated bioremediation of uranium contamination with promising results [5]. The method has been used in landfill characterization [6][7][8][9][10][11][12], spatial and temporal distribution of leachates [13][14][15], and gas migration within landfills [16,17]. Furthermore, the method has been used in sites contaminated with Non-Aqueous Phase Liquids (NAPLs) for characterization [18][19][20][21][22] and monitoring of the changes due to remediation [23,24].…”