Package ready for Czech used fuel disposal

The Czech Republic has two nuclear power plants, Dukovany, which has four VVER-440 units, and Temelin with two VVER-1000 units. Together they provide about one third of the country's electricity.

Škoda said that its packaging concept will see used fuel assemblies placed within sealed stainless steel shells, which are then placed inside a carbon steel cylinder, which is sealed at both ends.

"Materials with high corrosion resistance were selected," said Škoda, "which will guarantee the storage of used fuel for hundreds of thousands of years without breaking the cask's hermeticity." The corrosion tests were carried out with the ÚJV Řež, research centre, the University of Chemical Technology in Prague, and Energovyzkum in Brno.

The same packaging concept works for both fuel designs, Škoda said, noting that packages for VVER-440 fuel will take seven assemblies in a package four metres long, while those for VVER-1000 fuel take three assemblies and need to be almost five metres long. All the packages will be the same diameter, 91 centimetres, so they can be handled, transported and welded in the same way.

Škoda made a model of the cask as part of work to prove the design. It was made somewhat shorter and included cutaway sections so that it can become an exhibit in the future visitors centre of SÚRAO, the Czech Radioactive Waste Repository Authority, which is responsible for creating the underground repository in which the packages will be disposed of.