Detoxifying and Recycling Radioactive Metallurgical Wastes

The development of the nuclear power industry and the construction of a large group of nuclear power plants has caused substantial quantities of dormant scrap contaminated by radioactive substances to be accumulated within Russian territory. In accordance with the accepted terminology, radioactive metallurgical wastes (RMW) are metallic materials which contain radioactive substances in amounts exceeding the limits established by the standards presently in effect in this country. The concept of RMW also includes materials whose surface has been contaminated, if the level of radiation from 100 cm exp 2 of the surface exceeds 5 alpha-particles/cm per minute or 5 beta-particles/cm exp 2 per minute. Environmentally hazardous RMW is being accumulated in all countries in which nuclear-based technologies are employed. However, the approach being to the resolution of this problem differs, depending on the laws in effect in the given country and the economic situation. To reduce the volume of existing RMW and, accordingly, reduce the cost of their storage (both in designated areas and in underground sites), materials that have been contaminated by radioactive substances are baled or remelted. The latter method is obviously preferable, since the melting operation reduces the volume of the scrap by a factor of 5-8 and makes it possible to reuse (recycle) the metal. One important factor to consider is that the concentration of alloy steels - mainly chromium-nickel steels - in RMW can be as high as 15-20%.