LUCOEX / Work Package 5

KBS-3V Emplacement tests in ONKALO

Task 5.1. Detailed WP planning

The work package will be started with detailed planning of the WP contents. All the items on the activity list will be discussed in detail and described in the project plan document. Posiva will invite the other project partners to provide expertise to this planning phase.

Task 5.2 Demonstration of buffer components emplacement

The emplacement will be demonstrated in 2 whole-scale deposition holes in ONKALO with about 10 m distance. The main aim is to test the feasibility of the emplacement method. In the first tests concrete blocks will be used because the bentonite blocks do not tolerate the repeated test emplacements needed. Full scale bentonite blocks will be used in the final tests. Also a dummy “canister” will be emplaced but installation of buffer blocks is the main issue. The emplacement tolerances and accuracies are studied for finding suitable methods and equipment for the installation control.

The emplacement methods of the bentonite blocks will be developed so that it will be possible to carry out the emplacement with the needed speed and accuracy. For the emplacement demonstration, a vehicle frame equivalent to the deposition vehicle will be constructed and the installation machinery will be fixed to it. Designing the actual deposition vehicle is not included in this work. The electrical deposition vehicle is composed of the frame, wheels, driving engine and constructions where the lift with automatics can be assembled.

For ensuring the correct understanding of the deposition circumstances, a “dummy” canister will be emplaced with the deposition vehicle, although the canister installation development is not included in the scope of this project. However, only with canister installation it is possible to reach the full understanding of the buffer installation and of the impacts of tolerances and other factors on it.

Development of the buffer block emplacement automatics: The buffer block installation automatics and remote controlling of the machinery will be developed so that the required tolerances and uncertainty factors and installation safety aspects are taken into account. Activities:

  • Development of the remote controlling to the emplacement machinery, like electrical lifts, suction lifter and positioning instruments. Remote control is needed especially for the installation of bentonite blocks closest to the deposition hole top because of radiation.
  • Development of the steering automatics so that the blocks can be emplaced with highest possible accuracy and speed.

The first installations testing automatics will be realised in indoor premises by using the tower-like “deposition hole”. At this stage, the deposition vehicle can be replaced by a bridge crane.

When the automatics are functioning and the emplacement is working fluently, it is possible to begin the testing in ONKALO, where also an interim deposition vehicle will be used. At the event of emplacing the buffer blocks also a canister has to be installed by using the interim vehicle.

Development of the suction lifter: The suction lifter manufactured at earlier stages will be developed further and equipped with installation and positioning automatics. Activities:

  • The suction lifter will be developed so that the grip of the suction cups on bentonite can be improved for continuous use
  • Development of the vacuum system’s functioning and reliability

Development of the emplacement machinery positioning methods: The positioning methods of the emplacement machinery will be developed so that the buffer blocks can be emplaced accurately so that the deposition tunnel forms and other restricting factors are taken into account. Activities:

  • A wireless positioning method, with which the deposition vehicle can be placed correctly above the deposition hole and reach the required emplacement tolerances ±2 mm, will be developed
  • The positioning instrument will be tested in indoor premises
  • The positioning instrument will be developed so that its functioning in demanding and humid conditions can be guaranteed
  • The positioning instrument control system will be developed so that it can be used by remote controlling when needed

Sub-task 5.2.1. Development of the tool for filling the gap between the buffer and host rock

The gap between the buffer blocks and the deposition hole wall will be filled with bentonite pellets after the buffer block emplacement. The tool for filling the gap will be developed and tested.

The method and tool for filling the gap between the bentonite blocks and host rock with bentonite blocks will be developed. At the method development work, the realization of filling in different phases of the block emplacement will be studied. In the tool development, the studies will focus on the tool’s suitability for the developed method.

Sub-task 5.2.2. Buffer emplacement testing

The emplacement of buffer blocks and filling of gap between the buffer blocks and the wall of the deposition hole will be tested in ONKALO. Activities:

  • The emplacement of buffer blocks by using designed automatics
  • The testing of gap filling equipment

Task 5.3 Quality assurance and problem handling

The installation process of the buffer will be carefully planned, tested and reported to develop quality assurance procedures to ensure the overall quality of buffer during the disposal process.

Sub-task 5.3.1. Development of the quality requirements and quality assurance methods

The emplacement work and gap filling quality requirements will be defined. For this part, a description on the quality assurance will be elaborated and the needed quality assurance methods defined.

Sub-task 5.3.2. Development of the quality assurance equipment

The quality assurance equipment / control equipment needed for the control procedures will be designed and tested for the emplacement work and gap filling

Sub-task 5.3.3. Development of problem handling methods

The problem handling methods for the management and restoration of broken buffer blocks, gap filling and other exceptional situations will be developed. A process description is also needed for the handling of different problems and fault situations, which might happen during emplacement. At the event of emplacement, a bentonite block can fall and damage the structures, bentonite blocks or canister already placed in the deposition hole. The worst situation occurs when water runs to the deposition tunnel or holes before the tunnel has been sealed. In an extreme case all the emplaced buffer blocks and canisters have to be removed from the deposition holes. For this situations there has to be readiness to remove damaged parts from the deposition hole and replace them with new ones. Activities:

  • Developing methods for the removal of damaged parts so that the other already emplaced parts are not damaged
  • In addition to the bentonite blocks at emplacement humidity, also removal of the bentonite blocks that have reacted with water has to be made possible

Task 5.4. Final reporting of WP5

This task addresses the compilation of all WP 5 results in a final WP report.

Task 5.5. Integration and dissemination

This task is linked with WP1 and the planning and up-dating of plans are carried through by Task 1.1 “Integrated planning and outcome analysis”.

Sub-task 5.5.1. Integration

Active exchange of experiences and good practices between the project partners will be carried out during the work package duration. Experts will present advice of other participants on the WP test plan.

Researcher exchange / staff secondment activities will be organised between Posiva and other participants especially in connection with the demonstrations. Important project meetings will be held public with other participants in order to share information and brainstorm the solution jointly. The project partners will be offered the possibility to send their researchers to participate in the WP5 activities.

Internal and external experts will be invited to perform reviews on the WP5 project plan, interim results, demonstrations and final report.

Sub-task 5.5.2. Dissemination

Information about the developments related to this Work Package will be disseminated to different stakeholder and interest groups by the following activities: .

  • Documentary film. A 30-minute documentary film about the buffer components emplacement will be created
  • The documentary will be presented on the Posiva and the project web sites. Public viewings will be organised at different events like fairs and conferences participated
  • Emplacement demonstrations for authorities. Demonstrations that authorities will be invited to follow will be organised 3 times during the work package duration. Planned demonstration events: the buffer block emplacement tests at indoor premises; emplacement demonstration with quality control demonstration in ONKALO; problem handling demonstration in ONKALO.
  • Newsletter. A one-page newsletter with information on the work package activities’ progress will be composed in Finnish and in English and delivered to relevant national and local stakeholders / interest groups once a year.
  • Dissemination on websites. The work package will produce information to be published on the project’s (i.e. the website developed under WP1) and Posiva’s websites

Posiva’s communications department will be used to support the project personnel with the dissemination activities.

  • Localization: Finland
  • Facility: Onkalo HRL
  • WP-manager:Keijo Haapala