HE: Heater experiment - rock and bentonite thermo-hydromechanical (THM) processes in the near field

• Research unit: EU RFP
• Project number: 01.0072-4

Key words (English)

Borehole heating; dismantling; in-situ sampling; opalinus clay; bentonite; demonstration project;
Nuclear Fission; Radioactive Waste; Safety

Alternative project number (English)

EU project number: FIKW-2001-00132

Research programs (English)

EU-programme: 5. Frame Research Programme - 5.5.2 Nuclear fission

Short description (English)

See abstract

Partners and International Organizations (English)

NAGRA (CH), BGR (D), GRS (D), ENRESA (E)

Abstract (English)

The aim is to identify the coupled thermo-hydro-mechanical (THM) processes in both the bentonite buffer and the host rock clay formation after a medium-term heating phase at 100-C under saturated conditions.
A heating tube with a diameter of 10cm was installed in a 7 m deep borehole with a diameter of 30 cm. The gap between the heater and the clay host rock was backfilled with compacted bentonite blocks. A constant temperature of 100-C will be maintained at the surface of the heater in contact with the artificially saturated bentonite buffer for about 18 months. The THM response in both the buffer and the rock will be monitored in-situ.
During this time-period modelling and supporting laboratory work will be performed. Thereafter the buffer and part of the surrounding host rock will be excavated for characterisation at the laboratory.
Additional modelling will be done to confirm the predictions of the first modelling period.

References in databases (English)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 01.0072-4