The initial aim of the FEBEX experiment, back in 1997, was to study the behaviour of the nearfield components (EBS, host rock) for a high-level radioactive waste repository in crystalline rock.

Now, over a decade later, it is identified that:
  • Previous prediction/evaluation exercises indicated that the resaturation phase is poorly understood
  • There is a significant underestimation of resaturation times
  • Uncertainties in some key parameters (the evolution of thermal conductivity of partially saturated buffer, the scale dependence of measured thermal conductivities) are remaining
However, detailed understanding of early time coupled processes is needed to predict the nearfield evolution in terms of evolution of thermal conductivity of partially saturated buffer, the role of thermal convection, the on-set of corrosion/gas production, gas transport capacity of the nearfield (saturation history) and the geochemical evolution of the nearfield (e.g. iron/bentonite interactions).
 
It is in this context that the FEBEX experiment and similar experiments, covering long experimental timescales, are of large interest.

Impression of the FEBEX experiment during construction
Impression of the FEBEX experiment during construction