Features: Radionuclides carried by air, such as Drill -60, will be deposited in steel, making it have weak radioactive characteristics. 1963, that is, the year when the Partial Nuclear Test Ban Treaty was promulgated, the world's human background radiation level reached the peak of 0. 15 nsv/yr/ year higher than the natural level, but since then, the artificial background radiation index has dropped to 0.005 msv/yr/ year higher than the natural level.
However, diamond -60 still pollutes modern steel, because it has been recycled through the waste supply chain, and there are radionuclides with extremely long half-life such as carbon-14.
Extended data:
Modern steel is polluted by radionuclides because the atmosphere is used in the production process. Low background steel is called low background steel because it has not been polluted by nuclear. Gloria Bessemer, who obtained the American patent from 1857, transformed pig iron into steel, and now uses pure oxygen instead of air oxygen. In BOS, both processes use atmosphere, which is easily polluted by particles in the air.
Low background steel is mainly used for radionuclide detection devices that need the highest sensitivity, such as military Geiger counters (counting instruments for detecting radiation intensity), advanced medical instruments (lung and whole body scanning counters), photonics equipment, aerospace sensors and so on. Because when these devices are used to detect the radiation emitted by radioactive substances, an extremely low radiation environment is needed to achieve the best sensitivity.
References:
People's Network-Low Background Radiation Steel