Secondary-loop water purification at a pressurized-water reactor by a mesh-type high-gradient magnetic test separator

High-gradient magnetic separators (1 m³/h) were tested in the secondary-loop of a pressurized-water reactor to remove corrosion products. The matrix consisted of meshes of woven stainless steel wires with diameters between 50 and 220 μm stacked up to filter lengths between 20 and 68 cm. With a particle size of about 1 μm and an iron concentration between 5 ppb and 100 ppm a removal efficiency of 95 % was reached during cycle times up to more than 100 days. Special methods were applied to keep the pressure drop constant throughout most of the cycle time. Mößbauer-spectroscopy was used to characterize the composition of the corrosion products.