Part 2 of 2 Parts
Once the Finnish plant is completed, spent nuclear fuel will arrive in transportation canisters at the receiving area of the plant. Empty final disposal canisters will also be delivered to the receiving area. At the encapsulation plant, the transportation canisters and the empty disposal canisters will be tightly docked inside the fuel handling cell. Inside the cell, the spent fuel will be moved from a transportation canister to the drying area and then to a final disposal canister. When all the fuel assemblies from the transportation canister have been dried and placed in the final disposal canister, the final disposal canister will be filled with argon gas and tightly sealed with an inner steel cover.
The final disposal canisters that have been filled and sealed will then be moved to a welding station where the canister lid will be sealed with electron beam welding. This type of welding results in a strong, tight seam. The integrity of the weld will be checked with non-destructive testing such as x-ray or ultrasonic tests.
Sweden is also planning a spent nuclear fuel similar to the Finnish Posiva project that will use the same type of encapsulation and disposal system. The current timetable calls for the Swedish national radioactive waste management company Svensk Kärnbränslehantering AB is scheduled to begin construction of their spent nuclear fuel encapsulation plant and permanent geological repository sometime in the early 2020s. The project should take about ten years to complete.
The U.S. selected a site for a permanent geological repository in an old salt mine under Yucca Mountain in Nevada. The repository was supposed to open in 1999 to take spent nuclear fuel from U.S. nuclear power plants but was delayed by legal and environmental challenges. In 2009, preparations for the project were underway when the Obama administration with support from the Nevada Congressional delegation cancelled the project. Later, some remaining funds were used to finish the environmental report.
Now the U.S. government is trying to find a new location for a permanent underground spent nuclear fuel repository but is running into a lot of public opposition to such a repository. Even if a new site were selected tomorrow, it is estimated that it would take until 2050 at the soonest before a U.S. permanent underground geological repository could be opened to take spent nuclear fuel from U.S. nuclear power plants.
In the meantime, the spent nuclear fuel assemblies are piling up in the cooling pools at U.S. nuclear power plants. The pools are getting so full that unless some of the fuel assemblies are removed, the reactors will have to be shut down because there will be no way to refuel the reactors. There are dry storage casks made of steel and concrete that can be used to temporarily store spent nuclear fuel but there are technical problems with these casks. Another possibility being considered is to drill deep holes in basement rock to store spent nuclear fuel assemblies. Other countries are exploring ways to dispose of spent nuclear fuel.