Nuclear Weapons - The Importance of the Air

Air still contains some radioactive isotope such as cobalt 60 and others, that is left over from the hundreds of nuclear detonations. For a long time, you couldn't make steel via normal processes without being potentially contaminated with radioactive particles. So if you needed to make a geiger counter, or shielding for a sensitive radio bio assay chamber, so what would you do? Well, it probably wasn't impossible to make steel without environmental contaminates from nuclear tests, but it would have been expensive and difficult. Another option presented itself, which was harvesting steel made before the trinity test in 19 forty five. And this pre material became known in the industry as low background steel, low background because