The Fate of Repository Gases (FORGE) project

Abstract

AbstractUnderstanding the behaviour of gases in the context of radioactive waste disposal is a fundamental requirement and was the focus of the FORGE (Fate Of Repository GasEs) project. Of particular importance is the long-term performance of the bentonite buffers and the cement-based backfill materials that may be used to encapsulate and surround the waste in a repository for the geological disposal of radioactive waste and plastic clays, indurated mudrocks, and the crystalline formations that may be the host rocks of a repository. FORGE did not study salt host rocks or salt based backfill materials. FORGE has provided new insights into the processes and mechanisms governing gas generation and migration, with the aim of reducing uncertainty relating to the quantitative treatment of gas in performance assessment. This has been achieved by the acquisition of new experimental data coupled with modelling through a series of laboratory and field-scale experiments (performed at a number of underground research laboratories throughout Europe), and modelling. New methods were developed for upscaling from laboratory to field conditions, allowing the optimization of disposal concepts through detailed scenario analysis. Understanding a repository system to an adequate level of detail is required to demonstrate confidence in the assessment of site performance, recognizing that a robust treatment of uncertainty is desirable throughout this process.