Development of failure evaluation method for BWR lower head in severe accident; (1) high temperature creep test and creep damage model

Abstract

After the Fuku shima Daiichi nuclear power plant accident due to the pacific coast of Tohoku earthquake and Tsunami, we have been developing an a nalysis method considering creep damage mechanisms based on three-dimensional analysis for the early completion of the decommissioning of nuclear power plants. We have also been obtaining material properties that are not provided in existing databases or literature for the analysis. In this study, we measure the tensile and creep properties of low alloy steel, Ni-based all oy, and stainless steel at hig h temperatures near the melting points. Using experimental data, some parameters for the creep constitutive law and creep failure evaluation method are determ ined. In add ition, by comparing the creep rupture time between the finite element analysis and the experiment, the validity of the failure evaluation method is confirmed.