The Analysis of Effect on the Piping Due to the Displacement of EPR Nuclear Island Buildings

Abstract

The displacements of nuclear island buildings occur because of earthquake, thermal expansion, creep shrinkage etc. Because there are penetrations and some supports that connect to the wall of reactor building, the displacement loads must be considered when the piping and the supports are verified, the displacement loads have great effect on the piping and supports stress analysis. Studying the effect and looking for that how to reduce this effect are helpful to find a way to reduce the piping stress and the loads on the supports, and it is also helpful to make the plant safe. In this paper some piping calculation units of EPR project are showed as examples, the calculation units are done with a new software ANASYS PIPE, and finite element method is used. there are penetrations and supports that connects to the wall of reactor building in the calculation units, the building displacements due to earthquake, thermal expansion and creep shrinkage are considered, and the effect of displacement loads and the combinations of all kinds of loads under different category conditions on the piping and supports are studied, the result shows that the stress of piping and the loads on the supports caused by building displacement loads are prominent, but the piping and the supports can meet the requirement by optimizing the support concept.