Fractional scaling analysis for the thermal hydraulic behavior of pressurizer

Abstract Pressurizer is an important component in reactor coolant system of nuclear power plant. In the integral test facility, the steam-gas pressure in prototype is usually replaced with a down-scaled nitrogen-gas pressurizer for the convenience of operation and lower cost, which results in a distortion to the simulation of pressure. Thus a precise scaling analysis of the pressurizer is very necessary. In this work, the pressure and liquid volume of a steam-gas pressurizer is analyzed with fractional scaling analysis method. The scaling ratios for the height, diameter, surge pipe, electrical heat power are obtained and analyzed. It is found that there is no contradiction between these scaling ratios. Then the distortion between the nitrogen-gas pressurizer and the steam-gas pressurizer is analyzed and discussed. Finally, some suggestions for two controversial issues, wall heat accumulation and time scale in two phase phenomenon in the pressurizer are given.