Thermal coupling of HTGRs and MED desalination plants, and its performance and cost analysis for nuclear desalination

► The new HTGR + MED coupling scheme was proposed. ► KAIST coupling scheme uses PCHE without any intermediate loop. ► KAIST coupling scheme has independent structure between MED and heat sink. ► Water production capacity increases by 258% compared to previous researcher's results. ► Water cost is reduced by 9.0% compared to previous researcher's results. a b s t r a c t a r t i c l e i n f o The nuclear desalination based on the high temperature gas-cooled reactor (HTGR) with gas turbomachinery and multi-effect distillation (MED) has been drawing attention, because it can utilize waste heat for desalination. In this paper, research objectives are as follows: (a) proposing an optimal design of HTGR+MED systems and (b) performance and cost analysis for the HTGR+MED system. In the first step, the KAIST coupling scheme was proposed. It uses printed circuit heat exchangers (PCHE) instead of conventional heat exchangers without any intermediate loop and has the independent structure between MED plants and heat sink. In the second step, the KAIST version of DEEP (K-DEEP) code was developed for more practical cost and performance analysis of the KAIST HTGR+MED system. The desalination performance and cost analysis with the K-DEEP code were performed for the Gas Turbine-Modular Helium cooled Reactor (GT-MHR)+MED system. The maximum desalted water production capacity increases by 258% compared to the production capacity using the previous coupling scheme. The desalted water cost could be reduced by 9.0%. Finally, from the comparison of various nuclear MED desalination systems we confirmed the potential of the KAIST HTGR+MED system that may be one of the best desalination options in mass production of desalted water. Water crisis is one of the most serious problems that humans are facing. Desalination technologies are attractive and sustainable solutions for water crisis. Desalination processes can be divided by two categories: distillation processes and membrane processes. Recently a multi-effect distillation (MED) process in distillation processes and a reverse osmosis (RO) process in membrane processes are in the limelight because these processes can be improved further and their desalted water costs are commonly lower than water costs of other processes [1]. Desalination processes need energy sources: heat or electricity. Nuclear energy, fossil energy, renewable energy can be candidates. If we consider global warming, low cost, and sustainability , nuclear can be one of the best energy options. Researches on nuclear desalination systems are very active …