DEVELOPMENT, ANALYSES AND VALIDATION OF FE MODEL OF FSC 2005

Between 1986 and 2011, WAK GmbH packaged wastes from the experimental reactors at Karlsruhe research centre into about 3000 Konrad-type IV of steel containers for on-site storage, pending transfer to permanent disposal at Konrad. The containers have a welded body structure, a bolted lid and ISO corners for handling. Although the packages are consistent with Konrad’s waste acceptance criteria, none of them has so far been licensed for disposal in Konrad since the waste acceptance criteria was not defined until 2007, some 19 years after packaging first started. By modern standards, the existing evidence of performance of the packages that were created prior to 2007 are either inadequate or outdates. And from a radiation protection and economic considerations, repacking the existing conditioned waste into new licensed containers is not feasible. The German waste acceptance criteria allows licensing of packages like these type-IV containers retroactively if performance can be demonstrated by prototype testing and quality assurance by modern standards of the manufacturing of these containers can be provided. WAK GmbH has agreed with the responsible authority – Federal Office for Radiation Protection (BfS) with their consultant the Federal Institute for Materials Research and Testing (BAM) – to qualify the old packages retrospectively, with the following steps: 1. A new quality assurance program by modern standards, has to be established. 2. New prototype drop tests with an instrumented test specimen to study the performance and measure the strains on the container have to be carried out. 3. A finite element model of the prototype drop test specimen has to be developed and validated against the drop test. 4. Performance of the old packages has to be demonstrated using the results of the prototype drop test results by reasoned argument, and by finite element analyses based on the validated finite element model but modified to represent the old packages. This paper presents the modelling of the test specimen, analyses of the model in the drop test scenarios, behaviour of test specimen in the drop tests, and benchmarking of the analyses against the drop tests.