Knowhow, Skills and Experience
Projects Overview
Between 1989 and 1997, a comprehensive geological investigation programme was undertaken at Longlands Farm, near Sellafield, as part of a proposed Rock Characterisation Facility (RCF) promoted by Nirex (then the Nuclear Industry Radioactive Waste Executive). The objective of the programme was to evaluate the suitability of deep geological disposal as a long-term solution for managing higher-activity radioactive waste. Geological disposal is internationally recognised as a technically credible approach for isolating radioactive waste from the biosphere, provided that stringent safety and containment criteria can be demonstrated.
The Longlands Farm investigations focused on detailed subsurface characterisation through drilling, testing and modelling, establishing one of the most extensive datasets on deep geological conditions ever compiled in the UK.
Challenges
Technical and Geological Complexity:
Deep Subsurface Investigation: Investigating geological formations to depths approaching 2,000 metres, including complex volcanic sequences beneath glacial sediments and sedimentary cover.
Heterogeneous Geology:
Understanding the interaction between multiple lithological units — glacial deposits, Triassic and Permian sandstones and mudstones, and deeply buried Ordovician volcanics — to assess structural stability and groundwater flow.
Data Quality and Integration:
Ensuring high-integrity core recovery and the integration of multidisciplinary data into coherent geological models.
Solutions
Comprehensive Geological Investigation Programme
Drilling and Core Recovery: Completion of 65 deep boreholes and retrieval of approximately 19 kilometres of core to enable precise geological, geotechnical and hydrogeological analysis.
Multidisciplinary Surveys: Execution of extensive geophysical surveys, hydrogeological testing and groundwater sampling to characterise subsurface conditions.
Three-Dimensional Modelling: Development of detailed geological maps and subsurface models to support understanding of structural and fluid-flow behaviour.
Data Integration and Interpretation
Consolidation of drilling, core, testing and survey data into a robust knowledge base to inform technical evaluation of disposal concepts.
Use of iterative modelling to identify key geological controls on stability and containment potential.
Outcomes
Although planning permission for the Rock Characterisation Facility was refused by Cumbria County Council and upheld following a public inquiry, the Longlands Farm programme provided a landmark dataset on deep geological conditions in west Cumbria.
Key outcomes include:
- A substantial body of high-quality geological, hydrogeological and geophysical data supporting the UK’s understanding of subsurface complexity.
- Enhanced technical insight into the behaviour of deep volcanic and sedimentary sequences under investigation conditions.
- Development of methodologies and data-integration processes that remain relevant to modern geological disposal site evaluation.
- Recognition of the need for comprehensive geological confidence in order to support regulatory assessments and long-term safety cases.
The lessons learned from Longlands Farm continue to inform international practice in geological disposal, particularly in relation to drilling strategy, subsurface characterisation and risk assessment.
The team demonstrated exceptional adaptability throughout the project, with a deep understanding of regulatory compliance and a best-in-class approach to operations. Their ability to navigate complex challenges while maintaining the highest standards of safety and efficiency sets them apart as industry leaders