RD&D-Programme 2004 - SKB

Summary
The preceding RD&D-Programme from 2001 was concentrated on research and technology
development. Research with a focus on the assessment of long-term safety was emphasized
and viewpoints from previous reviews of SR 97 and RD&D-Programme 98 were dealt with in
depth. SR 97 was an assessment of the long-term safety of a deep repository for spent nuclear
fuel. This RD&D-Programme 2004 focuses its attention on the development of technologies
for fabrication and sealing of canisters for final disposal of spent fuel. These technologies are
needed for the application for a permit for an encapsulation plant which SKB intends to submit
during the coming programme period.
An overall goal for SKB is that the first stage of the deep repository for spent nuclear fuel
should be ready for initial operation in 2017. Regular operation should then be able to be
commenced in around 2023, before the storage chambers in Clab have become full. Timetables
covering such long periods of time naturally involve uncertainties and must be updated periodically,
but at the same time they provide an important basis for decisions regarding strategy
and priorities for the next few years. In 2002, SKB started a phase with site investigations in
Östhammar and Oskarshamn. Investigations of the bedrock are being conducted on sites near
the Forsmark plant and the Oskarshamn plant. The goal of the site investigation phase is to
obtain the permits that are needed to site and build the deep repository and the encapsulation
plant.
The next RD&D programme, which will be submitted in 2007, is expected to pay particular
attention to the deep repository technology and the continued work on alternative deposition
methods. The subsequent RD&D-Programme 2010 will above all given an account of SKB’s
system for managing and disposing of the low- and intermediate-level waste.
This RD&D programme presents the plan of action which was called for in the review of
RD&D 2001 and later also requested by the Government in connection with the approval of
this programme. The plan of action is summarized in Chapter 2 and presented in its entirety in
Appendix A. In accordance with the plan, SKB is now compiling the material that is needed to
apply for a permit for the encapsulation plant in 2006 and for the deep repository in 2008. The
licensing process and the decisions required to build the planned deep repository system should
then be able to be implemented so that construction can begin in around 2010 and operation in
2017.
The technology for disposal of fuel in accordance with the KBS-3 concept will be developed
in preparation for the permit applications for the encapsulation plant and the deep repository.
The work is focused on a reference design for each of the different parts of the system, and
the detailed design is emerging stepwise. The final choices will only be made after thorough
evaluation of safety, technology, costs and environmental aspects.
The canister, in which the spent fuel will be encapsulated prior to disposal, is in the focal point
of the technology development. In the reference design, the canister has a cast insert of nodular
iron and a five centimetre thick copper shell. The copper shell protects against corrosion and
the insert against deformation. The work of designing the canister in detail and evaluating the
fabrication, sealing and testing methods continues, see Chapter 5. The parts of the canister will
be fabricated by various suppliers and subsequently assembled and inspected in the canister
factory prior to delivery to the encapsulation plant.
In the encapsulation plant, the canisters will be filled with the spent fuel and then sealed. Two
welding methods are being developed in parallel at the Canister Laboratory: electron beam
welding (EBW) and friction stir welding (FSW), see Chapter 6. Methods for nondestructive
testing (NDT) are also being developed there. Qualification of the methods for fabrication,
RD&D-Programme 2004 5