LUCOEX / Work Package 4

KBS-3H

Task 4.1 Detailed WP planning

Detailed planning of the WP together with the other WPs to increase collaboration and fellowship.

Task 4.2 Manufacturing of distance blocks and buffer blocks for the supercontainer

Manufacturing of full scale KBS-3H buffer- and distance blocks has not been performed earlier. The success of the task is a necessity since the system design is dependent on the quality of the buffer blocks. A mould for uniaxial block pressing is being developed and should be used in the task. Isostatic compressing of buffer blocks is being tested and evaluated in WP5. Experience of uniaxial and isostatic compressing as well as the quality of the pressed blocks will be compared and evaluated. The result will be beneficial in the decision of which compression method to use in the future. D4.1.

Task 4.3 Upgrading of deposit machine

Earlier test have shown that the design of the KBS-3H deposition machine is successful, however, long-term testing has shown weaknesses in both the water cushion system as well as the control system. If these weaknesses are not addressed the long-term function of the deposition machine will be insufficient and the deposition process jeopardised, updates of the machine is therefore necessary. The updates should be completed and tested prior the installation of the multipurpose test. D4.2.

Task 4.4 Multipurpose test

The multipurpose test is designed to address several issues within the KBS-3H design and bring the knowledge of the system behaviour to a higher level. Performance of the task will also demonstrate the ability to properly install the system to fulfil the quality demands. The task is divided into several areas. D4.3.

In previous KBS-3H phases two supercontainers (SC) have been assembled. In these two concrete dummy buffer blocks were used. The assembly process with real bentonite buffer blocks is similar as with concrete blocks, but the tools needed, precision of the task as well as the need for controlled climate is a major difference. Since there are presently no tools for handling bentonite buffer blocks during assembly development, testing of such is also needed.

Previous supercontainer and distance block deposition tests were successful in the way that the method is proven to function. The tests were performed with concrete dummy supercontainers and blocks. Verification of the ability to properly deposit a supercontainer and distance blocks with real bentonite is needed. The emplacement test will show both the ability to do so as well as it is a vital part of the multipurpose test installation.

Full scale buffer saturation cannot be studied in a laboratory. Modelling of the process close to initial state can be done, but verification of the models is needed. Therefore the multipurpose test is designed to do this. Modelling of the KBS-3H saturation process is not included in this project.

Thermal spalling of the rock wall can lead to leakage paths and piping. The prevention of thermal spalling is identified as a key issue both in the KBS-3V and KBS-3H designs. In the KBS-3H case thermal spalling might occur at the top of the drift. Tests have shown that thermal spalling can be prevented or mitigated if counter pressure is applied to the rock. In the multipurpose test the buffer swelling pressure at the top of the drift is monitored closely. The test will show that the buffer will apply enough counter pressure to the rock in due time to prevent spalling.

The compartment plug in the KBS-3H design has been successfully tested in full scale as a freestanding component. In the multipurpose test the compartment plug is tested in combination with the other system components.

Buffer homogenisation is verified through sampling the buffer. Developing methods and equipment as well as performing the excavation and sampling of the buffer will therefore be done. Analyses of the buffer will be made and the results analysed and forwarded to modelling projects.

Task 4.5 Final reporting of WP4

This task addresses the compilation of all WP4 results in a final WP report.

Task 4.6 Integration

This task is linked with the other WPs in order to increase integration. The task addresses the following activities:

  • Expert advice of other participants on the WP test plan
  • Invitations to the other participants to participate in meetings and to attend at component assembly, installation and operation of the tests
  • Review of the WP final report by the other participants
  • Networking for new scientists
  • Localization: Sweden
  • Facility Äspö HRL
  • WP-manager: Magnus Kronberg
  • Contact:info@lucoex.eu