Regeneration of Metal Radioactive Waste from Radiochemical Industries for Metal and Alloy Recycling Purposes

Abstract

The paper proposes a processing method for metal radioactive waste (high alloyed stainless steel and its alloys) containing transuranic radionuclides. This type of waste is generated during operation and decommissioning of SNF reprocessing equipment at radiochemical production facilities. To ensure the recycling of valuable components, decontamination and conditioning of the regenerated ingots to high-quality metal is arranged in a two-staged process involving MRW remelting: its first stage involves in-depth metal decontamination under a layer of a refining flux, whereas the second stage provides for additional metal treatment to remove radioactive and stable impurities, as well as metal alloying to make up for the "burnt out" valuable components and to level its chemical composition. The process is implemented at an enterprise specialized in RW processing having appropriate infrastructure facilities and licenses authorizing relevant operations with radioactive materials. Metal radioactive waste regeneration results in a grade metal, which in terms of its residual radioactive contamination level can be released from radiation control and admitted to unrestricted use. It has been experimentally demonstrated that ESR, when used for MRW decontamination purposes, allows to obtain high-quality steel suitable for future reuse.

Recycled Radioactive Waste in the Space Industry

“…Reference [20] considers the recycling of metal radioactive waste (MRW). It is noted that radioactive contamination can penetrate deep into the metal and is not completely removed during etching and machining.…”

“…The total yield of the metal phase from the charge is 94.02%. From the above review, it can be seen that the existing technologies make it possible to almost completely deactivate the metal during remelting, radionuclides pass into slag and gas fractions [20], [21]. Existing technologies make it possible to isolate the desired component from the slag or decompose the entire slag into components for their use in industry.…”

“…The metal deactivated in this way can be used in industry without restrictions. Slags form about 10% of the initial mass of scrap [20]. Slag processing includes, for example, drying, grinding in a ball mill, roasting, and final grinding to obtain powders of various degrees of dispersion [24].…”