The objective of this study is to produce our own experimental data of physical properties of domestic concrete used in Korean NPPs, and to study on the thermal behavior of concrete exposed to high temperature conditions. The compressive strength and chemical composition of the concrete used in the Yonggwang NPP Units 3 and 4 (YGN 3&4) were analyzed. The chemical composition of Korean concrete is similar to that of US basaltic concrete. The thermophysical properties of the concrete, such as density, thermal conductivity, thermal diffusivity, and specific heat were also measured with a wide temeprature range of 20 deg C to 1100 deg C. The properties of concrete decrease with an increase in temeprature except for the specific heat, and particularly the conductivity and the diffusivity are a 50 percent decrease at 900 deg C as compared with these values at room temperature. The specific heat increases until 500 deg C, decreases from 700 deg C to 900 deg C, and then increases again when temperature is above 900 deg C. In this work, we also have performed the several experiments to simulate a transient thermal behavior of concrete exposed high temperature conditions. The measured data at the experiments includes the temperature profiles in the simulated melt and concrete. These experimental data will be compared with the results of transient heat conduction model in the concrete at initial or very late phase core / concrete interactions, which have not been modeled into the MCCI codes so far.
展开▼
