Structural integrity assessment of a spent fuel cask by using BS7910

This work provides a structural integrity assessment of a spent fuel cask using BS7910 Option 1 Failure Assessment Diagram (FAD). The containment barrier of the analyzed cask is designed following ASME Section III, Division 3, subsection WB. Accordingly, it is necessary to demonstrate the integrity of the materials (base material and welds) all along the range of operation temperatures, based on the determination of the corresponding reference temperature for nil-ductile temperature (RT NDT ). This approach may be very conservative for the case being analyzed, with a low LST (Lowest Service Temperature, -40°C) established to obtain the Certificate of Compliance for a Type B(U) package, and thick wall containment barriers. Thus, the present work provides an alternative analysis to evaluate and guarantee the structural integrity of the cask. The analysis is based on the use of the BS7910 and a number of engineering assumptions for the treatment of material properties, defect types and loading conditions.