RD&D-Programme 2004 - SKB

iosphere on a site, for example by changing the position of the shoreline, see section 20.8. Here
there is a strong coupling to the next programme, which deals with the evolution of the climate,
see below.
13.2.7 Climate
It is essential to describe what changes may occur in the future climate and see whether this may
in any way affect the repository. Previous climate changes with permafrost and continental ice
sheets will most likely occur in the future as well due to the earth’s movement around the sun.
But even though the earth’s astronomical movement is predictable, it is more difficult to predict
the exact course of climate change on earth. Many factors influence the climate. An additional
complicating factor is the human influence, such as emissions of greenhouse gases. For the
safety assessment it is important to be aware of the range of possible climates and their conceivable
evolutionary pathways on the site for the deep repository. The climate research supported
by SKB takes aim at this. The programme is described in Chapter 21.
13.2.8 Natural analogues
Nowadays studies of natural analogues do not comprise a separate programme, but are fully
integrated with the research on long-term safety, divided into different concepts and barriers.
SKI asserted in its review of RD&D 2001 that natural analogues should continue to be given
high priority, particularly material analogues. They further said that SKB should consider
utilizing the information that is already available from completed projects and that the value
of field experiments on previous sites should be considered. Anthropogenic material analogues
were held up as something SKB should consider studying. Analogues could be used to judge
the completeness of process descriptions, and it was recommended that SKB participate in EU
projects aimed at further evaluating already finished projects.
Studies of material analogues are dealt with in sections 16.2.7 and 17.2.15. SKB has followed
the work in the EU’s thematic network Nanet (Network to review natural analogue studies and
their applications to repository safety assessment and public communication). The network is
collecting references to analogues that are relevant to various processes and barriers in a repository.
Another, closer area for SKB is the Process Report. In the version that serves as a basis
for the SR 97 safety assessment, reference is made to natural analogues for 14 of the processes
that are dealt with /13-2/. The Process Report is being updated in preparation for SR-Can, and
additional examples can be included /13-3/.
13.2.9 Research in the Äspö HRL
The Äspö HRL is SKB’s facility for development, testing and demonstration of technology
for underground deposition of spent fuel. Several of the projects being conducted there are
concerned with long-term safety, and a large number of projects are completely focused on
such experiments. Most of these experiments concern the function of the buffer and the rock
in protecting the canister and serving as a barrier to the escape of radionuclides. There are also
experiments that concern the function of the canister and tests aimed at the fuel. Table 13-3
gives a number of examples of Äspö projects that are completely or partially concerned with
long-term safety. The table makes reference to sections in following chapters where more
information is available on the importance of the experiments in understanding and modelling
processes of importance of long-term safety. Sometimes the main purpose of a project is
technology development, and sometimes the borderline between technology development and
research may be fluid. Because long-term safety is naturally the aim of all development of deep
repository technology. When new technology is being considered, a judgement must be made as
to whether it meets the requirements of the safety assessment, or – as a first step in such a judgement
– arguments must be advanced in support of this.
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