Summary of industrial impacts from recycled radioactive scrap metals

During operation, decontamination, and dismantlement, nuclear facilities are generating significant quantities of radioactive scrap metal (RSM). Future decommissioning will generate even more RSM. The petroleum industry also generates RSM in the form of equipment contaminated with naturally occurring radioactivity. Finally, the accidental melting of radioactive sources in steel mills has generated smaller amounts of contaminated metals. Steel mills, smelters, and foundries could recycle these materials, which might then appear in finished products or as feedstocks used by other industries. If introduced in this manner, residual radioactivity can adversely affect the performance of certain products. Such products include computers and other devices that rely on integrated circuits. The most important effect of residual radioactivity on integrated circuits is a phenomenon known as 'single event upsets or soft errors.' Radioactivity can also adversely affect the performance of products such as photographic film and components designed to measure the presence of radioactivity. Radioactivity that raises background count-rates to higher levels could affect the performance of radiation monitoring systems and analytical equipment. Higher background count-rates would lead to reduced sensitivity and lower resolution in spectroscopic systems. The computer, photographic, and radiation measurement industries have taken steps to minimize the impact of residual radioactivity on their products. These steps include monitoring manufacturing processes, specifying material acceptance standards, and screening suppliers. As RSM is recycled, these steps may become more important and more costly. This paper characterizes potentially impacted industries and vulnerability and effects due to the presence of residual radioactivity. Finally, the paper describes practices used to limit the impact of residual radioactivity. (J.P.N.)