Challenges During the Decommissioning of the WAK Site: Dismantling of Highly Contaminated HLLW-Storage Tanks

The German pilot reprocessing plant WAK was shut down in 1990 after reprocessing about 200 Mg of nuclear fuels and is decided to be dismantled completely to the green field until year 2023. During the years 1994 until 2008 approximately 2.000 Mg of partly highly contaminated process equipment and 1.500 Mg of concrete structures corresponding to 99% of the radioactive inventory of 5E14 Bq of the WAK reprocessing building have already been dismantled. A major prerequisite for the complete dismantling of the WAK is the management of the 60 m³ high-level liquid waste (HLLW) with a total β/γ-activity of 8.0E17 Bq resulting from reprocessing. For this purpose the Karlsruhe Vitrification Plant (VEK) was constructed in the years between 2000 and 2005 and inactively tested in 2007. The subsequent nuclear test operation and routine hot operation of the VEK plant are planned to start mid-2009. In parallel to vitrification operation, dismantling of the four HLLW tanks in the storage buildings will be prepared for remote dismantling.