Alleged Corrosion is not a Threat to Final Repository

STOCKHOLM, November 30 - On Monday the 16th of November, the Swedish National Council for Nuclear
Waste held a seminar on copper corrosion, where international experts were
given the opportunity to pose questions regarding the alleged mechanisms of
copper corrosion in an oxygen-free environment that have been discussed
recently.

The seminar dealt with two main issues: one was the need for a better
understanding of the scientific basis for the alleged findings regarding
copper corrosion in an oxygen-free environment. The other was to identify
what more is needed in order to verify the existence of these mechanisms and
any future impact they might have on a final repository.

"We think that it is good that these issues are brought out and discussed
in a scientific forum. The seminar indicated that it is not just SKB that has
a lot of unanswered questions about what Peter Szakálos and his colleagues
presented," says Peter Wikberg, Research Director at SKB.

There was consensus during the seminar about the difficulty to foresee
complicated processes on the basis of individual experiments. There was also
general agreement that it would be good to do several experiments in order to
evaluate the actual existence of the alleged corrosion mechanisms, since the
conclusions drawn from studies published to date do not adequately explain
what might have happened.

During the seminar SKB's copper expert, Christina Lilja, described the
overall knowledge base on the corrosion issue and how SKB is working with
safety analysis. She explained, for example, how many different kinds of
calculations and experiments are needed in order to understand how the copper
canisters in the final repository can last for such long periods of time.

"Even though we have yet to find any evidence that this corrosion
mechanism exists, we have included it in our long-term safety analysis. We
can confirm that the final repository still lives up to our safety
requirements. What will have the greatest impact on the speed of corrosion in
the final repository are transports to and from the canister. It is primarily
the bentonite clay in the final repository, as well as the rock, that will
considerably reduce the effects of this transport," says Christina Lilja.

"We are putting together all the pieces of the puzzle that can provide
valuable knowledge about the final repository. It is in SKB's interest that
any questions with regard to copper corrosion in oxygen-free water are
straightened out as soon as possible. For this reason SKB has initiated a
number of studies, both experiments on their own and in cooperation with
external research institutes, and we hope to soon have the answers that are
needed in order to obtain a clear picture of this issue," concludes Peter
Wikberg, Research Director at SKB.

More information: Jimmy Larsson-Hagberg, Press Relations Manager, SKB, +46-8-459-84-83,
+46-70-269-91-15 Jessica Alsenlid Otterstål, Press Officer, SKB, +46-8-459-85-27, +46-70-242-07-27