There's a few reasons why Low Alpha Copper/Steel/lead etc metals have certain uses.
One is for MRI scanners, they need low amounts of radioactivity around them, that goes for the reinforcing rods in the concrete to the screws and nails in the walls, right up to the machine itself.

The other is for electronics, less radioactivity means less errors. In this case, the Lead in the solder. Its not only the atomic bombs, but the fact that once the Leads been refined and smelted and melted, it looses radioactivity over the years.
So in this case, 200 yr old Lead is worth more than 100yr old lead, and such. Where to get this Lead? Sunken ships keels.....