Why does when the steel was produced affect the background radiation? A girder that existed in 1938 still existed in the 40’s and 50’s, why is it not contaminated but new steel was/is?
In: 11
Part of making steel is blowing air up through the boiling metal to have the free oxygen in the air remove some of the impurities of the metals, particularly carbon content which turns into CO2.
Unfortunately if your air contains radioactive cobalt-60 some will remain in your steel making your steel mildly radioactive
Nuclear tests starting in the mid 40s significantly increased the quantity of radioactive elements in the air so that any steel made with free air would be radioactive enough that it would be a constant false positive for something like a Geiger counter
Low background steel was mainly from old warships like the German fleet from WW1 that was scuttled in Scapa Flow Scottland. Since this steel was already turned from iron into steel it didn’t have to have the air blown through it again and didn’t pick up excess radioactive dust and could be used for sensitive equipment
Latest Answers