EB: Engineered barrier emplacement experiment in opalinus clay

• Research unit: EU RFP
• Project number: 99.0779

Key words (English)

Compacted bentonite; granular bentonite backfill; remote emplacement; bentonite buffer material; demonstration project;
Nuclear Fission; Radioactive Waste; Safety

Alternative project number (English)

EU project number: FIKW-2000-00017

Research programs (English)

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

Short description (English)

See abstract

Further information (English)

Full name of research-institution/enterprise:
Nationale Genossenschaft für die Lagerung radioaktive Abfälle NAGRA

Partners and International Organizations (English)

Coordinator: Empresa Nac. de Residuos Radioactivos, Madrid (E)

Abstract (English)

Objective: The aim is to demonstrate the feasibility for emplacing a clay barrier consisting of a base of highly-compacted bentonite blocks, and pneumatically injected pellets in the upper part of a dummy canister, and to study the H-M performance of this buffer material under satured conditions.6 m length of a 2.4-m diameter drift, with a dummy canister in the middle, will be backfilled with two types of bentonite buffer components: highly compacted blocks in the lower part, and pellets, in the upper part. The test zone will be confined between two watertight concrete plugs, and the drift will be artificially hydrated. Laboratory tests for butter characterisation are foreseen. Mechanica land hydraulic behaviour of the backfill and host rock will be monitored.

Achievements: At mid term the gallery has been excavated; the bentonite blocks are ready for installation; a series of characterisation tests of bentonite pellet-based material have been done; the emplacement technique has been selected and prepared; the dummy canister constructed; hydration system designed and gathered; and the sensors and monitoring and control system gathered and tested. A preliminary modelling 3/4'scoping calculations'3/4 of the test was carried out to help in the design of the backfill characteristics and hydration system definition. The 'in situ' test construction will be made between February and May 2002.

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: 99.0779