TY - GEN A1 - Wille, Frank T1 - Spent fuel behavior under Transport Conditions N2 - German packages for the transport of spent nuclear fuel are assessed with respect to specific transport conditions which are defined in the safety regulations of the International Atomic Energy Agency. In general, gastight fuel rods constitute the first barrier of the containment system. The physical state of the spent fuel and the fuel rod cladding as well as the geometric configuration of the fuel assemblies are important inputs for the evaluation of the package safety under transport conditions. The objective of this paper is to discuss the methodologies accepted by German authority BAM for the evaluation of spent fuel behavior within the package design approval procedure. Specific test conditions will be analyzed with regard to assumptions to be used in the activity release and criticality safety analysis. In particular the different failure modes of the fuel rods, which can cause release of gas, volatiles, fuel particles or fragments, have to be properly considered in these assumptions. The package as a mechanical system is characterized by a complex set of interactions, e.g. between the fuel rods within the assembly as well as between the fuel assemblies, the basket, and the cask containment. This complexity together with the limited knowledge about the material properties and the variation of the fuel assemblies regarding cladding material, burn-up and the operation history makes an exact mechanical analysis of the fuel rods nearly impossible. The application of sophisticated numerical models requires extensive experimental data for model verification, which are in general not available. The gaps in information concerning the material properties of cladding and pellets, especially for the high burn-up fuel, make the analysis more complicated additionally, and require a conservative approach. In this context some practical approaches based on experiences by BAM within safety assessment of packages for transport of spent fuel will be discussed. Ongoing research activities to investigate SNF mechanical behavior in view of gas and fissile material release under transport loads are presented. T2 - IRSN Conference on Safe Transport of Radioactive Material CY - Fontenay aux Roses, France DA - 13.11.2018 KW - ENSA KW - SNL KW - Real transport KW - IAEA KW - Drop test KW - Multi-Modal Transportation Test KW - Radioactive KW - ACT KW - NCT KW - Hot cell KW - Activity release KW - Fuel rod KW - Fuel rods KW - Burn-up KW - Cladding alloy KW - Criticality safety analysis KW - Containment analysis KW - Fuel assemblies KW - Spent fuel PY - 2018 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/46880 AN - OPUS4-46880 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany