PROJECT RESULTS / Annual Technical Results
Year 3 : ESDRED TECHNICAL RESULTS to January 2007
Module 1: Buffer Construction Technology for Horizontal Disposal Concepts
Summary :
After formulation, computer modeling and/or laboratory characterization
of the considered buffer/backfill materials at a sufficient level of detail
(all carried out in Year 1 or Year 2 of the Project), a number of demonstrations
have been undertaken in various workshops. These demonstrations have been
successful for all Partners in Module 1. ANDRA has succeeded in producing
13 good quality full-scale bentonite rings through cold compaction. NAGRA
has emplaced a granular buffer with the desired dry density in a 360°
near-full-scale steel mockup by using a double-auger machine. ONDRAF/NIRAS
has achieved a 100% backfilling of the gap between the container and the drift
lining in two near-full-scale mockups. One demonstration used a cementitious
material; the other used a range of pre-selected granular materials (sand,
cement, bentonite and mixtures thereof). The emplacement of a cementitious
backfill at an industrial level will be demonstrated in Year 4 on a full-scale
30 m long mockup, for which the design has now been made.
Two other partners have been running their in-situ tests. After the successful
startup of a pilot case, the GRS is now satisfactorily running all four saturation
experiments on various sand-bentonite mixture seals in clay at the Mont Terri
URL. Also at Mont Terri, the NDA, formerly as NIREX, has been conducting a
non-intrusive monitoring experiment with the aim of advancing the application
of cross-hole seismic tomography to advance repository monitoring capabilities.
Three of the four planned measurement campaigns have been performed so far.
Work completed :
- Report “In-Workshop Demonstration of Buffer Prefabrication / Installation”
- ANDRA has succeeded in producing 13 good quality full-scale bentonite
rings through cold compaction - view pictures
- NAGRA has emplaced a granular buffer with the desired dry density in a
360° near-full-scale steel mockup by using a double-auger machine -
view pictures
- EURIDICE, executing the demonstration tests for ONDRAF/NIRAS, have achieved
a 100% backfilling of the gap between the container and the drift lining
in two near-full-scale mockups. One demonstration used a cementitious material;
the other used a number of pre-selected granular materials ranging from
sand, cement, bentonite and mixtures thereof - view
pictures. Also, EURIDICE has made a selection of the seal material for
emplacement in annular opening under in-situ conditions in the PRACLAY gallery
in the Mol URL
- GRS have started up all four saturation experiments on various sand-bentonite
mixture seals in clay at the Mont Terri URL
- NDA (NIREX) have installed the equipment and made adjustments for the
non-intrusive monitoring experiment based on cross-hole seismic tomography
at niche HG-A in the Mont Terri URL view pictures. Three of the four planned measurement campaigns have been
performed so far.
Work in progress :
- ONDRAF/NIRAS, EURIDICE:
- Preparation of full-scale grout backfill emplacement test (see drawing):
Drawing ONDRAF/NIRAS In Progress 1: Drawing of the concept of the 30 m long full-scale mockup for grout backfill
- Confirmation through laboratory testing at CERMES (France) of the selected seal material for the test in the PRACLAY gallery in the Mol URL
- GRS :
- Is satisfactorily running all four saturation experiments on various sand-bentonite mixture seals in clay at the Mont Terri URL.
- Is continuing the seal saturation test on mockup 2 in the laboratory (see graph)
Graph GRS In Progress 1: Evolution of the pressure at the bottom, middle and top of the laboratory mockup number 2 seal (status end April 2007)
- NDA (NIREX) : At the ETH (Zürich) a PhD study is in progress to develop
an anisotropic computer model of the test environment.
Important Events Planned for 2007 :
- ONDRAF/NIRAS, EURIDICE:
- Construction of the 30 m long full-scale mockup for grout backfill (and execution of the test ?)
- Construction of the PRACLAY gallery in the Mol URL and emplacement of the seal material in the annular opening of the dedicated steel structure
- NDA (NIREX) :
o Execution of the fourth and final measurement campaign after nitrogen injection in the microtunnel.