TR: What now?
AM: Within the next five years, almost every nuclear power plant will have dry-cask storage: the waste will be moved from storage pools to outdoor concrete-and-steel casks inside plant security perimeters. As an interim solution, that’s quite safe. But eventually the casks will corrode and break down and release radioactive material into the environment, though it will probably take hundreds of years. That’s why we need geological storage.
TR: What’s the right geology?
AM: Waste should be stored in a reducing environment [one not exposed to free oxygen], and this usually means underneath the water table, though salt formations can be reducing even if they are not below the water table. The Swedes and Finns are planning to put their waste inside granite and metamorphic rock, and the storage casks will be below the water table. And that’s all okay. Spent fuel–which is just uranium dioxide, fission products, and actinides [radioactive elements, including plutonium]–is relatively stable under such conditions. With no free oxygen, it just sits there.
TR: Will we still need such storage even if future reactors burn more of the plutonium–or even if future generations decide to reprocess some of the old spent fuel to recover plutonium?
AM: Yes. The French reprocess spent fuel, but they still need a repository. They are doing research on a site at Bure, in northeast France. It has a kind of sedimentary rock that’s relatively fine grained, and it’s a reducing environment.
TR: So where are the suitable storage locations in the United States?
AM: There are lots, all over the country.
TR: Then it should be easy to name two or three.
AM: I haven’t studied anything in detail, and I don’t want to get anybody upset. But we have a huge country, and there are many locations. One thought, though, is that sites could be in locations where people already have a comfort level with nuclear power, which is how the Swedes and Finns have been successful.
TR: It took 22 years and $8 billion to get nowhere on Yucca. Politics aside, how long will it take, and how much will it cost, to get U.S. storage sites opened?
AM: We didn’t get nowhere. We learned quite a bit. We should set aside something on the order of a few decades to get this right. It will cost billions, but that’s part of the price of nuclear power.