(GRS 243) FEBEX - Investigations on gas generation, release and migration

Norbert Jockwer, Klaus Wieczorek

The Spanish reference concept for the disposal of radioactive waste in crystalline rock formations foresees to emplace the waste canisters in horizontal drifts surrounded by a clay barrier of high-compacted bentonite /ENR 95/. In order to demonstrate the
technical feasibility and to study the behaviour of the near-field of a high-level waste repository the Spanish Empresa Nacional de Residuos Radiactivos (ENRESA) started the FEBEX project (Full-scale engineered barriers experiment for a deep geological
repository for high-level radioactive waste in crystalline host rock) in the Grimsel Test Site in 1995, with the assistance of the Swiss Nationale Genossenschaft für die Lagerung radioaktiver Abfälle (NAGRA). The project had the three objectives:
• Demonstration of the construction of the engineered barrier system,
• Study of the thermo-hydro-mechanical (THM) processes in the near-field,
• Study of the thermo-hydro-chemical (THC) processes in the near-field.