RD&D-Programme 2004 - SKB

Programme
Work on the design of the repository, and thereby coherent requirements on a candidate site, will
be resumed in conjunction with the preparations for a new safety report for the final repository
for other long-lived waste. At present, this work is planned to be commenced at the end of this
decade. See also section 25.5.
25.3.2 Safety assessment
An initial safety assessment of a final repository for other long-lived waste was performed in
1999 /25-1/.
Conclusions in RD&D 2001 and its review
The safety assessment was thoroughly reviewed by SKI and SSI with the aid of an international
team of experts. The conclusions from the review by both the international team of experts and
the regulatory authorities have been reported in /25-3, 25-4/. Both the regulatory authorities and
the team of experts draw the conclusion “that a great deal of research and development work
remains to be done before the level of knowledge in this field is comparable to that associated
with the final repository for spent fuel.”
In the review of RD&D 2001, SKI also points out that the account of what will be included in
the coming safety assessment is too scanty and difficult to assess, and that SKB needs to update
the (previous) safety assessment, and that the work should begin immediately so that SKB can
perform a renewed safety assessment after completion of the site investigations.
SKB’s plans, which were presented in RD&D 2001, entail that the repository will not be sited
and built for more than 30 years, and we wish to make use of this time to conduct the necessary
research and development.
Newfound knowledge since RD&D 2001
No new safety assessment has been done; efforts have instead been focused on research and
development, see further 25.4.
Programme
After the site investigations, we will have the time and the data necessary for a new safety
assessment. The fact that the investigations are geared towards the repository for spent nuclear
fuel is of no great importance, since basically the same type of site data are needed. The exact
point in time for a new safety assessment will be chosen with reference to other safety assessments
and resources. Figure 25-1 shows that according to current planning, a safety assessment
will be submitted to SKI and SSI in 2011, see also section 25.5.
25.4 Research
The investigations that are being done are mainly aimed at furnishing data and models for
assessing the long-term safety of a final repository for other long-lived waste. This knowledge is
being built up partly through the research supported by SKB and partly by international studies
in the field. We have found that among the most important processes that can affect the properties
of the barriers in the long term are the following:
• Corrosion of steel and aluminium in a concrete environment (formation of gas and corrosion
products).
• Concrete degradation in saline waters.
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