Abstract: A filtering system for the treatment of radioactive fluids, comprising filters with interchangeable filtering elements, positioned within a casing. The casing has a cover and the filter assembly is housed inside a radiation shielding chamber provided with an access opening. At least one opening is provided in the chamber wall opposite the filter which is closed with a removable filter casing cover. The casing cover is shaped to be received in the shielding chamber opening and when in position seals the casing. The cover is also designed to be received by a shielded cask for the transportation of the said filtering element when the spent element is removed and replaced. The filter element is suspended from the cover and hence is removed from the casing simultaneous with the removal of the cover. In the method according to this invention, removal of spent elements is effected without subjecting personnel to high radiation dosage since the filter elements are shielded at all times during removal.