Impact of the specified valves characteristics on the transient processes of nuclear reactor core cooling

Abstract

The results of computational analysis of hydraulic characteristics of the fast acting motor valves are presented in this paper. The significant difference is identified be-tween calculated characteristics of the change of the valve’s pressure loss coefficient during the valve’s open-ing/closure process in respect to those used as default ap-proach in codes for thermal-hydraulic calculations of nu-clear reactors. The change of valve’s hydraulic resistance at the very beginning of an accident causes the reduction of coolant flow rate delivered from the emergency core cool-ing system, abatement of core cooling intensiveness and the increase of maximal temperature of fuel element sur-face.