Accurate fracture mechanics analysis methods for subsurface or surface defects, including their interaction with the cladding

Abstract

The fracture analysis methods are specialized to account for the shape and position of the defect at or under the surface of cladded nuclear vessels subjected to pressurized thermal shocks. The improvements bear on the LEFM shape factors, plasticity corrections in relation to the overall plastic strain in the cladding and to the ligament yield for a sub-surface crack, and on extension of the cleavage crack initiation criterion to account for variable K I K IC condition along the crack tip and for size effects.