Full-scale Engineered Barriers Experiment FEBEXe - Observations & Results

As the experiment is running now over more than 12 years, a unique dataset including crucial long-term observations in terms of sealing, saturation and corrosion is generated.

The current status is that the outer buffer is practically saturated and hydration is in progress at the inner buffer. This was predicted by THM models, but occurs at a slower rate than expected.
 
Especially, one can observe that: 
  • Temperatures in the bottom part continue being higher than those in the sides and upper part for each section. Temperature trends are increasing very slowly in the buffer and in the rock close to the heater.
  • The total pressure in general continues increasing in the buffer and also in the contact bentonite/rock and bentonite/plug.
  • The water content in the buffer continues increasing at all points. The biggest differences can be observed in the inner part but it is clearly rising elsewhere.

 

Relative humidity measurements in section F2 of the FEBEX experiment
Relative humidity measurements in section F2 of the FEBEX experiment

The GTS underground facilities are also available to interested 3rd parties for underground testing and research. The GTS offers cost-effective access to a fully developed, well characterised underground research facility with round the year logistical support - please contact Dr. Ingo Blechschmidt, Head of the Grimsel Test Site, for further details.