Packaging Strategies to Ensure Safe and Reliable Intermediate and Final Storage of Damaged Irradiated Nuclear Fuel

Despite today’s increasingly more reliable operation of nuclear power plants, damaged fuel rods exist in many nuclear power plants. Managing preparations for disposal or intermediate storage of such rods has been a growing problem. For instance, most of the dry storage systems for used irradiated nuclear fuel do not allow storage of damaged fuel rods together with intact fuel. Also final repositories have limitations on presence of moisture, which present difficulties in accepting failed or broken fuel rods. Consequently, more data is required to enable both intermediate and final disposal of damaged irradiated fuel. Transport solutions, as well as intermediate storage solutions, for damaged fuel also have to be developed to fulfil national and international expectations. Investigations in a hot-cell laboratory, with methods for mechanical testing and advanced microscopy together with its inherent knowledge of materials integrity, fuel reliability and activity build-up, is an important vehicle to deliver the necessary data to ensure a safe and reliable intermediate and final storage of damaged spent fuel. It is, however, then also necessary that damaged fuel stored a long time in pond is available for the investigations. Safe and efficient handling of the package at the plant and the hot-cell laboratory as well as safe transportation are crucial elements. A hot-cell can also develop methods for conditioning of damaged fuel for acceptance in available intermediate and final storages for non-failed fuel. To perform the necessary investigations or conditioning, it is hence a key to transport the damaged fuel to the hot-cell and to have ability to manage the disposal of the fuel after examination in a manner suitable to national and international requirements. The transport of damaged fuel requires packages designed and licensed for this kind of material. The packages that brings irradiated fuel to a hot-cell for examination does not take larger quantities and can only be used for bringing material for investigation. Even so, it is currently very few packages able to transport damaged fuel rods of any quantity .The packages for loading spent fuel in a nuclear power plant are too heavy and bulky for most hot-cells. The Studsvik strategy to enable a solution for future storage of damaged spent fuel hence includes ? Update/upgrade of the PDSR prolonging the life of existing older B(U)F packages ? Investment in a new package, NCS 45, certified to transport damaged fuel ? Preparations for a new pool facility with functional requirements enabling also the reception of the nuclear power plant spent fuel packages