In the current research phase, the focus is on investigating the performance and the safety of the engineered and natural barriers in deep geological repositories. Experiments that investigate disposal concepts on a 1:1 scale provide valuable measured data and system understanding. FEBEX («Full-scale Engineered Barriers Experiment») is an example of such a demonstration experiment on emplacement of high-level waste.
The Spanish waste management organisation ENRESA initiated the FEBEX heater experiment in 1997 and several international partners are now involved. The first of the two heaters was excavated in 2002 and the second followed in August 2015. «With a duration of 18 years, FEBEX is the longest-running heater experiment under realistic disposal conditions», explains Florian Kober, the Nagra project manager responsible for the excavation: «The sensors installed around the heaters provided comprehensive data during the experiment and this has been supplemented with the excavation of the two heaters.»
More than 1300 samples were collected during the excavation of the second heater alone and these are now being analysed in more than 18 laboratories worldwide. Kober expects the first results of the analyses to be available around summer 2016.
The international partners have different expectations with respect to the results of the project. The Swedish waste management organisation SKB, for example, is mainly interested in whether microorganisms are present in the bentonite backfill material.