DROP TEST PROGRAM WITH THE HALF-SCALE MODEL CASTOR® HAW/TB2

BAM (Federal Institute for Materials Research and Testing) is the competent authority for mechanical and thermal safety assessment of transport packages for spent fuel and high level waste (HLW). In context with the package design approval of the new German HLW cask CASTOR® HAW28M several drop tests were performed by BAM with a half-scale model CASTOR® HAW/TB2. The cask is manufactured by GNS (Gesellschaft für Nuklear Service mbH) and was tested under accident transport conditions on the 200 tons BAM drop test facility at BAM Test Site Technical Safety. The sequences of the tests comprise cumulations of nine-meter free drop onto an unyielding target in various most damaging drop orientations to cause maximum package damage, and a drop from one meter onto a steel puncture bar onto the most sensitive part of the container. The subsequent release of radioactive substances must not exceed a value specified in the dangerous goods transport regulations, and radiation shielding and nuclear safety must be guaranteed [1]. For this purpose the test specimen CASTOR® HAW/TB2 was instrumented on 21 measurement planes with altogether 23 piezo-resistive accelerometers, five temperature sensors and 131 tri-axial strain gauges in the container interior and exterior, respectively. The strains of four representative lid bolts were recorded by four uniaxial strain gauges per each bolt. Helium leakage rate measurements were performed before and after each test sequence. The paper presents experimental results of the half-scale CASTOR® HAW/TB2 prototype (14,500 kg) and provides insight into the complexity of test procedure, extensive test methods and measurement data logging.