Aims of the Colloid and Radionuclide Retardation (CRR) Experiment

The broad objective of the Colloid and Radionuclide Retardation Experiment (CRR) experiment was to significantly improve understanding of the in situ retardation of colloid-associated, safety-relevant radionuclides in the vicinity of an engineered barrier/host rock interface.

This was achieved by:

  • Investigation of the stability of bentonite colloids in different types of water (Grimsel groundwater and FEBEX bentonite porewater).
  • Investigation of the extent of bentonite colloid formation at the EBS/host rock interface.
  • Investigation of the in situ migration/retardation of bentonite colloids in fractured host rocks.
  • Improving the conceptual models for colloid and colloid-mediated radionuclide transport for reactive transport modelling.
  • Further development, calibration and validation of existing (transport) codes and databases for the analysis of in situ retardation of safety relevant radionuclides in association with colloids.
  • Definition of the degree of transferability of model predictions and of results from laboratory experiments to the geosphere.


Colloid and Radionuclide Retardation 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.