PROJECT RESULTS / Annual Technical Results
Year 4 : ESDRED TECHNICAL RESULTS to January 2008
Presentation
Module 1- Module 2
- Module 3
- Module 4
Module 1: Buffer Construction Technology for Horizontal Disposal Concepts
Summary :
In the 4th project year, the partners ANDRA and NAGRA have finalized their demonstration work within ESDRED. After having succeeded in producing 13 good quality full-scale bentonite rings in Year 3, ANDRA has subjected one of them to a destructive shear strength test and also successfully tried a simplified alternative handling technique.
GRS has continued with the sand-bentonite seal saturation experiments it was running in Year 3, both the mock-up 2 and the 4 in-situ boreholes in the Mont Terri URL.
O/N and EURIDICE have constructed their mockup for the full-scale backfill test with grout, which is planned to be executed early in Year 5. EURIDICE, in cooperation with the CERMES institute (FR) has confirmed its selection of MX-80 as the bentonite to use in the Plug test in the Mol URL PRACLAY gallery. The latter was constructed at the end of Year 4.
The NDA (formerly NIREX) has advanced well in the program of non-intrusive monitoring experiments at Mont Terri. Five of the (now) foreseen 9 Measurement Campaigns were performed in Year 4. In parallel, a computer model of the anisotropic test environment was developed by the Technical University of Zürich (ETH).
Work completed:
- ANDRA has finalized their demonstration testing by performing a lifting test and a Brazilian shearing test with some of the prefabricated buffer rings - view pictures
- NAGRA has cleaned and stored their reduced-scale steel mock-up.
- GRS has been continuing the gradual saturation of the seals in surface mock-up number 2 and in the Mont Terri URL. At the end of the 4th project year, the mock-up seal was close to full saturation, and the 4 in-situ seals had all reached well-advanced saturation levels.
- O/N and EURIDICE have subcontracted the construction of the full-scale mock-up to SMET Tunneling. At the end of the 4th project year, the mock-up construction was complete with the internal heater switched on, set on reaching the target temperature - view pictures. A shed has been built around the mock-up to protect it from harsh weather conditions - view picture. In cooperation with BASF, who are the manufacturer of the backfill grout, a pre-test was performed to identify the right mixing conditions for the grout during the injection test view pictures).
- EURIDICE, based on computer simulations and laboratory tests in cooperation with the French CERMES institute, selected MX-80 bentonite as the material for the Plug test in the PRACLAY gallery of the Mol URL.
- NDA have achieved full saturation in the backfill of the Mont Terri HG-A tunnel, the object of their non-intrusive monitoring experiments. Measurement Campaigns 4, 5, 6, 7 and 8 were performed. The anisotropic model was set up and is in the process of being fine-tuned in an iterative process using experimental data from the Measurement Campaigns. A code for full wave conversion is in the process of being developed. At the end of the 4th project year, only one Measurement Campaign remained to be undertaken.
Work in progress:
- ONDRAF/NIRAS, EURIDICE:
- Tendering for the re-design of the steel annular structure for the Plug 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)
- NDA (former NIREX):
- Development of the Full Wave Inversion Code at the ETH (Zürich)
- Preparing for the nitrogen injection phase and the ensuing last Measurement Campaign of the non-intrusive monitoring experiment at Mont Terri
Graph GRS In Progress 1: Evolution of the pressure at the bottom, middle and top of the laboratory mockup number 2 seal (status end February 2008)
Important Events Planned for 2008:
- ONDRAF/NIRAS, EURIDICE:
- Post-test evaluation of the full scale grout mockup after the backfill test (executed April 8th 2008). This will involved borehole sampling and taking 1 slice of the mockup. One of the main objectives will be to check the homogeneity of the backfill and to assess the level of void filling.
- Emplacement of the MX-80 bentonite seal material in the annular opening of the steel structure in the PRACLAY gallery, by the end of Year 5.
- NDA (NIREX):
- Nitrogen injection in the HG-A tunnel and execution of the last Measurement Campaign
- Finalization of the Full Wave Inversion code (by ETH).
- GRS:
- Finalize saturation experiment in mockup 2 (saturation fully achieved)
- Progress as far as possible with the in-situ experiment in the 4 boreholes in at Mont Terri (try to achieve full saturation and perform nitrogen injection to see gas break-trough)