Preliminary study on high temperature transport technology for molten salt in pyroprocessing

Pyroprocessing technology is one of the most promising technologies for an advanced fuel cycle with favorable economic potential and intrinsic proliferation-resistance. In pyroprocessing technology, the development of high-temperature transport technologies for molten salt is a crucial prerequisite and a key issue in the industrialization of pyro-reprocessing. However, there have been a few transport studies on high-temperature molten salt. Three different salt transport technologies (gravity, suction pump, and centrifugal pump) were investigated, a suction pump transport method was selected for molten salt transport owing to its flexibility. An apparatus for suction transport experiments was designed and installed for the development of high temperature molten salt transport technology. About 2 kg of LiCl–KCl eutectic salt was prepared by mixing 99.0%, LiCl and KCl and drying in a convection dry oven at 200 °C for 1 h. Predissolution tests of the prepared LiCl–KCl eutectic salt using the melting reactor of the experimental apparatus was carried out to investigate the dissolution behavior of the prepared LiCl–KCl eutectic salt. From the results of the pre-dissolution test, it was found that prepared LiCl–KCl eutectic salt was well dissolved at 500 °C. High temperature molten salt transport experiments by suction are currently being performed using the prepared LiC–KCl eutectic salt. The preliminary experimental results of lab-scale molten salt transport showed a 99.5% transport rate (ratio of transported salt to total salt) under a vacuum range of 100 m torr–10 torr at 500 °C.