Year
2012
Abstract
In Germany, low and intermediate level radioactive waste from nuclear and other industries, research facilities and increasingly decommissioned nuclear installations is handled and prepared for interim storage and later disposal in the licensed KONRAD repository which will be operated by BfS (Federal Institute for Radiation Protection). Based on the official disposal requirements, waste conditioning and packaging is realized by different waste producers into box-shaped and cylindrical containers made of steel, cast iron or concrete. The KONRAD acceptance criteria define two package categories, called Waste Container Class I (ABK I) for lower activity levels and Waste Container, Class II (ABK II) for higher activity levels. The admission of the conditioned and packaged waste requires approved containers as well as certified waste conditioning and packaging procedures. BAM (Federal Institute for Materials Research and Testing) is responsible for container design testing and evaluation of quality assurance measures on behalf of BfS under consideration of the KONRAD disposal requirements. Besides assessing the container handling stability (stacking tests, handling loads), design testing procedures are performed including fire tests and drop tests from different heights and drop orientations. The combination of experimental investigations and numerical calculations in conjunction with materials and components testing is the basis of the safety assessment concept of BAM. Recently the latter institution started the research project ConDrop - Numerical Drop Test Analyses of Steel Sheet Containers for the KONRAD repository - to develop a reliable Finite Element (FE) Model describing the mechanical behavior of a box shaped steel container during a drop test and to determine unfavorable scenarios within future assessment procedures of steel sheet containers mostly used as ABK I and II containers with accident safe packaging. This paper deals with design testing aspects, experiences and perspectives within BAM assessment procedures of containers for the waste disposal in KONRAD. Particularly, evaluation methods of drop tests for steel sheet containers, from experimental testing to numerical calculations, are explained where testing conditions (target, drop orientation), waste fixing system and leak tightness and integrity requirements are closely considered.