Criticality safety analysis for GNS IQ® – The Integrated Quiver System for damaged fuel

The phase-out of nuclear energy in Germany has triggered the demand for a comprehensive solution to dispose of damaged fuel rods, normally remaining in the fuel pond until the final shutdown of the NPP. In order to establish a disposal concept for damaged fuel rods suitable for the needs of German utilities, GNS has developed a first of its kind solution, the Integrated Quiver System for Damaged Fuel (GNS IQ®), which can be loaded into the transport and storage casks of the CASTOR® family also by GNS. The GNS IQ® features a robust yet simple design with a high mechanical stability, a reliable leak tightness and large safety margins for future requirements on safety analysis. It can be easily adapted to a large variety of different damaged fuel rods and tailored to the specific needs of the customer. The quiver is adaptable e.g. in length and diameter for use in other types of transport and storage casks and is applicable in other countries as well. The paper gives a general overview of the disposal concept and provides a description of the Integrated Quiver System for Damaged Fuel with the focus on criticality safety assessment.