Investigation and evaluation of ductile fracture behaviors in LWR piping under bending load

Instead of the postulated pipe break philosophy, the Leak-Before-Break (LBB) concept has been recognized to be applicable to the LWR piping design based on more realistic subcriticai crack growth, fluid leakage and fracture evaluation by the fracture mechanics methodology(1) (2). In the mean time, some piping integrity research programs which are intended to validate or establish the LBB design criteria are also under way(2) - (5).