Year
2008
Abstract
The Federal Institute for Materials Research and Testing (BAM) is one of the two German competent authorities responsible for design assessment of packages to be approved in conformity to the IAEA Regulations for the Safe Transport of Radioactive Material (TS-R-1) [1]. BAM assesses the mechanical and thermal safety analysis, the safe containment of the radioactive material and the quality assurance program during manufacturing, operation and maintenance. The methodology in the field of safety analysis including associated assessment criteria and procedures has evolved rapidly since last years. New aspects relating to analysis and assessment methodologies are summarized in this paper. BAM requires clear and detailed descriptions of the concepts and the aims for the primary mechanical and thermal safety demonstrations. The concept significantly influences the depth of an experimental or calculation proof. All relevant boundary conditions with respect to TS-R-1 [1] must be taken into account, e.g. the assessment of stresses, strains and fracture mechanical considerations from -40°C to maximum operational and thermal accident temperature. In general for new construction principles of package design the implementation of experimental tests (drop tests) in the approval process is necessary. Additionally, component tests could be important depending on the safety analyses concept. Whether and to what extent drop tests are necessary, depends on the individual construction of the packaging, the materials used and implemented and identified safety margins in the package design. The procedure needs to be sufficiently justified by the applicant in the safety analyses concept. Numerical calculations by means of the finite element method are currently part of safety analyses concepts of different package design approvals. The calculations can be carried out according to the particular loading situation (strain rate) statically or dynamically. In the containment analysis, BAM requires detailed and comprehensive qualification of seals and the lid closure systems as well as a calculation of an activity release based on well specified release values, depending on the radioactive contents. Concerning quality assurance, a fully aligned program for manufacturing, assembling, operation and maintenance is necessary to get the compliance control with the final Safety Analyses Report specified in the approved certificate before starting any manufacturing process.