Limit load and stability analysis of 500 MWe PHT elbow with throughwall cracks for leak-before-break qualifications

摘要

The leak-before-break (LBB) concept is now universally used to design the primary heat transport (PHT) piping of pressurised heavy water reactors (PHWR). Similarly, in India also, the LBB concept is being used to design its future generation 500MWe PHWR PHT piping. This requires detailed fracture mechanics analysis of different piping components, e.g. straight pipes, elbows and branch tees. In the present paper, limit loads and J-integrals have been evaluated for one typical elbow in a steamgenerator inlet line with various postulated throughwall circumferential and axial flaws. Finally, it has been shown that the elbow satisfies the requirements of LBB behaviour.