RWE NUKEM completes dismantling of biological shield at the Kahl Nuclear Power Test Plant (VAK)
- 360 tons of concrete and steel removed
RWE NUKEM GmbH of Alzenau, a subsidiary of RWE Solutions AG, based in Frankfurt am Main, has completed the dismantling of the biological shield at the Kahl Nuclear Test Power Plant (VAK) after nine months of work.
The biological shield in a nuclear power plant is a concrete barrier around the pressurized reactor tank which acts as a shield against radioactive emissions. After many years of operation, the biological shield had become radioactive. Radiation safety testing revealed that remote dismantling of the shield would be necessary.
According to Walter Hackel, reponsible for the dismantling project in Kahl, the goal was to dismantle and remove enough material to ensure that the remaining structures could subsequently be approved for unrestricted free release.
Intensive planning and trial operations during the preliminary phase of the dismantling project led to the selection of the most suitable equipment for the job: a small, remote-controlled excavator which can be equipped as needed with a range of different chisels or with hydraulic shears. The unit was then used to dismantle the concrete and reinforcing steel as well as the cooling conduits. Approximately 310 tons of concrete and some 50 tons of steel were removed from the site.
All appropriate radiation safety requirements were met during the dismantling operation. Separation of contaminated air was ensured, and the complex logistics of material removal were managed effectively.
Dismantled material was subjected to radiological testing under the supervision of the expert appointed by the regulatory authority and allocated to different waste categories. Roughly 60 per cent of this material were designated for storage at the Bavarian Interim Storage Facility in Mitterteich. The remaining material was approved to be utilized at a landfill site by the regulatory authority.
RWE NUKEM assumed responsibility for dismantling of the VAK as business management and general contracting firm in early 2001. In 1961, the VAK generated the first electricity produced with nuclear energy into the German power network. The facility was decommissioned in 1985.