Journal of Nuclear Fuel Cycle and Waste Technology

As nuclear power plants approach the end of their spent fuel storage capacity or are scheduled to be decommissioned, the need for dry storage is increasing. In preparation for dry storage, spent fuel must be packaged to maintain mechanical integrity during handling and transportation in accordance with the legal requirements for delivery of domestic spent fuel dry storage (Spent Fuel Delivery Regulations, Nuclear Safety and Security Commission Notice), and integrity must be maintained to prevent gross rupture of spent fuel rods. Intact spent fuel that has not been damaged may satisfy the legal requirements for dry storage, but the structural integrity of damaged spent fuel must be confirmed for handling and transportation. Various types of damage may occur during handling of spent fuel in a nuclear power plant and based on the damage to the grids supporting the fuel rods reported by the IAEA, an integrity assessment was performed by assuming damage to the outer surface of spacer grids supporting fuel rods. When damage such as loss of the outer plate occurs in some of the grids of the fuel assembly, buckling of the surrounding normal grids that are not damaged and excessive deformation of the fuel rods may occur during transportation. In this study, we evaluated the grid buckling and fuel rod bending to assess the mechanical integrity during handling and transportation of spent fuel by assuming grid damage.

Keywords

Fuel rod bending, Grid buckling, Handling, Mechanical integrity, Spent fuel, Transportation