M.W KOZAK (United States of America): The papers we heard this morning largely represent the views of the geological disposal community. There is another community of radioactive waste professionals who is dealing with near surface disposal problems, however, and in my view many of the issues discussed in those papers have been dealt with by the near surface disposal community; some of the wording is different, but you will find a parallel line of publications in the literature which come up with the same concepts independently — the shift away from validation towards confidence building, for instance. That shift probably happened in the near surface disposal community earlier than in the geological disposal community, largely because the near surface disposal community has to put waste into the ground immediately, so there were very imminent problems which had to be solved — we had to move to decision making very rapidly and in a very concrete way. The second point I wanted to make is that there is a significant new approach in a regulation that has been proposed in the United States of America. It is a two-tier system recognizing that analyses will need to be more stylized in the far distant future than in the near distant future. The two tiers are an acknowledgement that, with uncertainty growing as you move into the future, there may be a need to specify a different dose limit or a different dose constraint as you move into the distant future. That is what the US Environmental Protection Agency (EPA) recently proposed for use at Yucca Mountain.
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