In-pile test of the crud separator system in the HBWR. (II)

The out-of-pile test results of the advanced crud separator system was previously investigated. It was suggested that the system characteristics (separation factor) depended on magnetic susceptibility of crud, crud particle diameter and flow rate, and that utilization of the crud size enlarger, a high gradient magnetic system, was effective especially in the lower separation factor region. After the out-of-pile test, the system was shipped to the HBWR (Norway), and the final in-pile test was carried out under the operating conditions similar to BWR. As the test results, the separation factor decreased with increasing inlet crud concentration in the lower inlet concentration region, and crud production (or release) rate and crud separation rate seem to reach the state of equilibrium at the inlet iron concentration approximately 6 ppb for this system size. It was also suggested that separation factor became higher when coolant temperature increased. (author)