Effect of boron carbide addition on liquidus temperature and thermophysical properties of austenitic stainless steel in a liquid state

Fukuyama, Hiroyuki*; Higashi, Hideo*; Yamano, Hidemasa   

Thermophysical properties of molten mixture of 316L stainless steel (SS) and control-rod material (BC) are necessary for the development of computer simulation codes that describe core degradation mechanisms during severe accidents in nuclear power plants involving sodium-cooled fast reactors. To satisfy this demand, the present authors first measured the liquidus temperatures of the SS-BC mixtures up to 10 mass% of BC by using differential scanning calorimetry (DSC). Based on these data, the thermophysical properties of the molten SS-BC mixtures were measured by using a noncontact high-temperature thermophysical property measurement system, which consists of an electromagnetic levitator, a superconducting magnet, a laser-heating system, a high-speed charge-coupled-device camera, a data-logging system, and a gas-control system. The density, surface tension, normal spectral emissivity, specific heat capacity, and thermal conductivity of molten mixtures were measured over a wide temperature range with high accuracy in a noncontact way. This paper provides the liquidus temperatures and thermophysical properties recently updated in the project.