EURAD-2 - D12.1 - Initial State-of-the-Art RAMPEC

Past research related to deep geological disposal of radioactive waste has established a strong understanding of radionuclide behaviour in clay, crystalline, and cementitious systems under equilibrium conditions. However, during construction, operation and post-closure of a geological disposal facility (GDF), inevitably the near field (NF) - engineered components and part of the host rock (HR) - will be subjected to “perturbations”. These perturbations can be subdivided into following effects: thermal, hydraulic, mechanical, chemical, biologic and radiation. Under perturbed conditions, the behaviour of radionuclides and, in general, dissolved species in a disposal environment (e.g. gas, chemotoxic elements, organics...) remain poorly constrained. At present, no integrated, model-based description exists for such systems, and the ability to represent the chemical evolution of in-situ conditions has not yet matured to the level required for mechanistic transport modelling at the near-field scale.
RAMPEC aims to address these gaps by gathering new experimental data under relevant perturbing conditions, enabling the required modelling of radionuclide retention and migration in such environments, and supporting upscaling to disposal cell–scale.
The scope of the work focuses on clay, crystalline, and cement systems, with particular attention to perturbations most relevant to each. In addition, the present initial State-of-the-Art (SOTA) report serves as a baseline against which the RAMPEC workplan has been developed. It provides a synthesis of the existing knowledge, offers comprehensive references to past projects and published results, and identifies key challenges to be addressed.