Heat Transfer Analysis Due to Curve Pipe of Reactor Cavity Cooling System in RDE Reactor Taswanda Taryoa , Muhammad Yunus, Mohammad Subekti and Sri Sudadiyo

Abstract. The 10 MW Indonesia’s Experimental Power Reactor (RDE) which is currently in detail design period is a
High Temperature Gas Cooled Reactor (HTGR)-type and planned to be operational in the Puspiptek Serpong area in
2027/2028 at the latest. The reactor applies helium gas coolants, graphite moderator, 17% 235U enrichment fuels and
has 8 control fuel rods. To design a nuclear reactor, there are many safety aspects which should be taken into account
and one of them is piping system in reactor cavity cooling system (RCCS). To enhance the RDE safety, RCCS
system is required to support primary helium coolant and the system can be properly applied for both normal
condition and under accident. During the reactor accident with no power supplies and cooling pump down, the
RCCS works in a natural circulation by using air in cavity and water in the cooling pipe. The process of radiative
heat transfer from Reactor Pressure Vessel (RPV) to Flat Water Cooled Pipe (FWCP) and the natural circulation of
air cavity and around the WCP were taken into account in 3-D numerical model using FLUENT, a spectacular
computational fluid dynamic code. This paper deals with the similar previous mentioned process from RPV to WCP
applying curve pipes. It is suggested that the curve-pipe RDE RCCS have better simulation and hence achieving
better analysis of the heat transfer process in the curve-pipe RDE RCCS. From the simulation results, the
temperature at bottom air cavity is higher than the top of the cavity. The temperature contour of water in the pipe
also changes because of the heat transfer influence from RPV. Finally, gravity and radiation are very important
parameter inputs to simulations in order to be able to approach the real conditions.