Abstract
Time history analysis with multiple excitations is an analysis method that can perform reasonable evaluation. However, the analysis method which is common to be used to evaluate seismic performance of nuclear power plants is not time history analysis with multiple excitations but modal analysis under covers all floor response spectra all supporting response so far. Therefore there are few examples quantitatively showing how much evaluation can be rationalized by time history analysis with multiple excitations. Time history analysis with multiple excitations can be expected to have a large reasonable effect on long laid pipe like a secondary heat transfer system of loop type FBR. In this report, when a time history analysis with multiple excitations is used for aseismic evaluation of pipes which is long laid in the vertical direction and horizontal direction, as an example the secondary heat transfer sysytem of MONJU, how much rationalization effect is obtained compared with the modal analysis under covers all floor response spectra all supporting response. As a result, it was confirmed that the reduction effect of 30% or more in the long laid pipe in the vertical direction, and the reduction effect of 18% in the long laid pipe in the horizontal direction.
