High energy pipe break hypothesis and engineering practice shall be taken into account and performed during nuclear power plant design due to defense-in-depth concept unless leak-before-break or break preclusion concept is applied. High energy pipe breaks potentially occur in the high stress area and break locations can be recognized by specific regulations based on mechanical analysis of piping systems. Engineering measures shall be applied to mitigate the consequences caused by high energy pipe breaks later.
From engineering point of view High Energy Line Break analysis requires an essential knowledge in the different fields, such as: structural and dynamic mechanics, hydrodynamics, plant arrangements and so on.
Aims of this paper consist of two aspects: definition of break locations associated with engineering practice of piping stress analysis and a conservative model of anti-whip analysis based on some assumptions. Comparison results are given after analytical investigation of the piping whip analysis with different numerical modeling and tools at the same time. An example of such comparison between transient model and energy balance methods is performed based on some basic assumptions in relation to specific piping layout.
The simplified calculation model appears well for a conservative estimation of pipe whip characteristics, both for maximum displacements of piping and maximum loads impacted on anti-whip restraints.