Abstract: The experience of developing methods of magnetic filtration (MF) for the purification of various aqueous media from impurities of iron oxides has been studied. An analysis of the reasons for the successes and failures of previous researchers in the development of methods and means of magnetic filtration has been carried out. Theoretical prerequisites for new technical solutions for high-gradient magnetic filters (HGMF) are considered. Laboratory experiments were performed on a high-gradient filter with a superconducting magnetic system using model solutions to determine the basic characteristics of the method. It has been established that it is sufficient to use permanent magnets based on rare earth elements (NdFeB, SmCo) as a magnetic field source to calculate the required magnetic field strength gradient. Designs of high-gradient filters with systems based on permanent magnets, as well as a program for numerical simulation of the process of processing particles of corrosion products of various phase and dispersed composition in a high-gradient magnetic field for these filters, have been developed. The tests results of VGMF of various designs for water treatment of spent fuel assemblies' (SFA) storage pools on a full-scale test bench—a prototype of a transport nuclear power plant (NPP) and a VVER-440 reactor plant—are presented. The efficiency of purification of the coolant of the first circuit from activated corrosion products by ion-exchange and high-gradient magnetic filters was compared when performing reagent-free decontamination of equipment. Certification of the innovative design of the VGMF with a system based on permanent magnets, which can be used to purify the water of heat supply systems of urban utilities from corrosion products, was carried out. © 2023, Pleiades Publishing, Inc.