Engineered Barrier Systems (EBS) - BENTONITE properties and applications

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Dates: 18.06. - 22.06.2018 (optional FMT-URL visit, 23.06.2018)

Duration: 5 days, with general lecture hours from 08:00 am to 5:00 pm

Location: Nagra's Grimsel Test Site near Guttannen Canton Berne, Switzerland (, with an additionally lab visit at University of Bern (Rock-Water Interaction Group). Accommodation can be arranged in the villages of Guttannen or Meiringen.

Flyer : Engineered Barrier Systems (EBS) - BENTONITE properties and applications PDF
Application Form : EBS Course Application Form DOC

Aims and Objectives of the Bentonite Summer School:

As part of the Grimsel Training Centre programme 2018, Nagra offers a 5-day workshop at the Grimsel Test Site covering various aspects related to Engineered Barrier Systems (EBS) and specifically bentonite. Participants will get an introduction to engineered barrier / bentonite requirements, properties and applications in radwaste topics.

International and national experts will provide keynote lectures and experience, discussion forums will allow the exchange of knowledge and current research strategies. GTS lab visits will provide first hand insights of ongoing experiments and will support the discussion of related topics in the course.

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The course aims to impart both theoretical and practical knowledge and experience. The course shall help participants in defining, managing, planning, tendering and carrying out their own field (URL) and lab experiments at various scales and how to interpret data and results with respect to their safety case. The topics will be transferable to various field investigations and implementer safety requirements.

Theoretical blocks and lab visits will alternate. The daily activities will be organized in lecture blocks, and visits to in-situ experiments at the Grimsel test Site. In addition, a lab visit is planned either at the University of Bern or ETH Zürich.

The main topics covered by the summer school course are:

  1. Safety requirements
    • General and site/hostrock/waste specific requirements
  2. Clays and Bentonites as engineered barriers
    • Properties (chemical, physical, thermohydromechenical)
    • Bentonite origin, types and properties
    • THM/THC behaviour
    • Interactions with cements, metals, host-rocks and gasses
    • Bentonites/clays and
    • Bentonite production and quality
  3. Modelling bentonite behaviour
    • Codes and approaches
    • Validation with field data
  4. Experiments
    • Scale issues (lab – mock-up – large scale)
    • Safety requirements and large-scale experiments (demonstration vs processes understanding)
    • Designing and constructing experiments
    • Monitoring and excavating experiments
    • Management of experiments
  5. Onsite visit and discussion of GTS Experiments (and others)
    • Planned: HotBENT (high temperature buffers), CIM (Carbon Iodine Migration), …
    • Running: CFM (Colloid Formation & Migration), GAST (GAs permeable Seal Test), MACOTE (MAterial COrrosion TEst), …
    • Completed: FEBEX (Full Scale Engineered Barrier EXperiment), …

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Grimsel Test Site (GTS)

The Grimsel Test Site (GTS) located in the Swiss Alps was established in 1984 as a centre for underground Research and Development (R&D) supporting a wide range of research projects on the geological disposal of radioactive waste. International partners from Europe, Asia and North America are working together at this unique facility.

The (GTS) is located at an altitude of 1730 metres in the granitic rock of the Aar Massif in Switzerland. It lies at a depth of around 450 metres beneath the surface and is reached by an access tunnel belonging to the local hydro-power company (Kraftwerke Oberhasli AG, KWO). The GTS tunnel system is around one kilometre long and was excavated in 1983 using a full-face tunnelling machine (diameter 3.5m).

During the Bentonite Summer School, daily transport from a hotel near the site to the GTS, lunch and coffee breaks are organised by Nagra and included in the course fee. GTS provides all necessary facilities, beside adequate working space, seminar rooms, bathrooms - Wi-Fi is also available. The only thing we miss are windows!


CHF 3,500.00 (excl. travel, accommodation and VAT). We are happy to support you to organise appropriate accommodation or local transportation if desired. A pre-booking in Hotel Rebstock in Meiringen ( ) has been made.


Participants shall bring their own laptop. Clothing should be adequate for an early summer mountainous regional environment.


The expected number of participants is a minimum 15 and a maximum 20. Please note that in the case of not reaching the minimum number of participants the course will not be take place. The deadline for preliminary registration is March 31st, 2018.

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.
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