SD-20K: A B(U)F Transport System for Final Storage Containers

For radioactive waste with negligible heat generation, final storage in the Konrad repository requires that the waste is conditioned and safely packed in containers with specified characteristics. While most of the Konrad containers (KC) with historical waste from the fuel fabrication sites in Hanau and Karlstein can be transported as industrial packages (IP), a minority requires transportation as type B(U)F packages. However, the KCs by themselves are not designed to meet all B(U)F requirements, especially with regard to the mechanical tests for accident conditions of transport (ACT).The SD-20K transport system provides the necessary additional protection in the form of a protective packaging for the KCs. It consists of an outer steel frame with rigid foam plates to protect the contents from mechanical and thermal effects, and of an inner container with a double-sealed lid that serves as the containment system (in concert with the conditioning of the wastes and the KC itself). The outer dimensions correspond with those of a standard 20’ container. The SD-20K consisting of the SD-20K protective packaging and a single KC (maximum total mass of 20 Mg) fulfills the requirements towards a type B(U)F package. Size differences between different KC types are accommodated by spacers (rigid foam with a steel casing) within the inner SD-20K container. In addition to the protection of the contents, an important design goal for the SD-20K was to provide quasi-automatic unloading in the Konrad repository. Several innovative features of the transport system (e.g. completely automatic unbolting and opening of the inner SD-20K lid, a vehicle loading bed that can be telescoped) serve to restrict the dose exposure from manual handling to a single operation without any direct contact with the KC itself.While our presentation will focus on the SD-20K design features and our safety assessment for KC inventories, we will also give a short outlook on future prospects of the design, which could easily be accommodated for the transport of other wastes destined for final storage.