Development of an advanced LMR steam generator free from SWR with a double tube bundle configuration

This paper describes the activities made at KAERI to develop an advanced LMR(Liquid Metal Reactor) steam generator which is free from SWR (Sodium Water Reaction) to resolve the concern of the SWR possibility and improve the economic feature of an LMR. The steam generator design houses two tube bundles that are functionally different and its tube bundle zone is radially or vertically divided into two regions. The SG is equipped with hot and cold fluid tube bundles, medium fluid and a pump. It prevents the occurrence of a sodium water reaction while sodium is still being used as the coolant for the primary heat transport system. The feasibility of using the SG with a double tube bundle for an actual use in a LMR plant is evaluated by setting up the skeleton of the NSSS for various possible configurations of the SG tube bundles. Analysis was made for various types of the new steam generator with a double tube bundle. Since the heat transfer in the SG is made among the three different fluids, it comes to have its unique heat transfer characteristics. The analysis showed the possibility for the occurrence of an undesirable reversed heat transfer not only in the integrated single-region bundle type but also in the integrated double-region bundle type. The performance analysis revealed practical performance characteristics for the various bundle configurations. Also the feasibility study for the various NSSS configurations with the new SG is described. (authors)