Evaluation method on LBB for the piping of demonstration FBR

A study on the applicability of Leak Before Break (LBB) concept has been performed for the design of Demonstration Fast Breeder Reactor (DFBR) in Japan. Application of LBB concept is expected to reduce the cost of the plant. In this study, the scenario for LBB evaluation is proposed. The scenario is based on the discussions of the initial stage defect assumption, the crack propagation, the leak detection and the final fracture. Experiments and analyses of crack propagation and final fracture behavior support evaluation methods based on the scenario. The feasibility of the piping design of DFBR using LBB concept is evaluated in this study.