Thermal-hydraulic aspects of SCWR design

The Supercritical Water-Cooled Reactor (SWCR) is one of the most promising concepts for Generation IV candidate systems. The SCWR has several advantages compared to the existing light water reactor (LWR) systems, including the use of direct cycle combined with single-phase working fluid, high thermal efficiency, and the existing experience with the proven technology used in fossil power plants. A common feature of most Supercritical Water-Cooled Reactor (SWCR) designs that have been proposed to date is a highly nonuniform temperature distribution inside the reactor core. This is mainly due to the combined effects of core peaking factors and limits imposed on coolant flow rate. Furthermore, statistical uncertainties in the evaluation of hot spot factors normally contribute to an increase in the range of temperature distribution that must be considered in reactor design. The purpose of this paper is to present the results of analysis on the SCWR in-core temperature distribution, aimed at identifying possible methods of reducing the maximum coolant temperature and improving the thermal-hydraulic characteristics of the proposed reactor system. (author)