Preliminary Study for the Design of Mesh Region in Cold Trap

Sodium-cooled fast reactor (SFR) or liquid sodium test loop system need sodium purification system because it is essential to control the purity of liquid sodium for successful operation. Inadequate management on the sodium purity leads to problems such as plugging of pipes, corrosion of structural materials, insufficient cooling by sodium, etc. Cold trap is so far known as the most promising method to purify the liquid sodium in sodium test loop or SFR in case that most concerned impurities are oxygen and hydrogen, due to its simplicity in operation as well as efficient purification. The basic concept of the cold trap is to utilize the dependency of the solubility on temperature. Sodium oxide or sodium hydride can be crystallized inside the cold trap. It has been reported that mesh packed trap has higher efficiency than un-packed trap has. From this point of view, it is necessary to build up some strategies on the design of mesh region. It has been studies that trapping efficiency and capacity are dependent upon the configuration of mesh region. In this study, therefore, some parameters which affect characteristics of the wire mesh region are investigated. Trapping performance such as trapping efficiency and capacity can be highly dependent upon the configuration of mesh region. It is therefore important to understand phenomena inside the mesh region such as hydraulics and crystallization and to build up design strategy. This study categorizes the parameters which affect the trapping performances and will give insight to study mesh region characteristics, and eventually to design the mesh region for performance enhancement of cold trap