low alpa lead

[Bloodman14]

Hey, gang, I was watching some show on the History Channel, in which some explorers found a shipwreck that had a bunch of lead pigs in it; the narrator mentioned it was 'low alpha' lead. Now, I know that low alpha lead is desirable for most industrial applications, not to mention us casters, but I was wondering; is it possible to render common, 'high alpha' lead into 'low alpha' lead? I realize that 'high alpha' lead is the result of nuclear testing back in the late '50's and early '60's, so is rendering the lead even practical? And why, exactly, is low alpha lead so desirable? What properties does it have?

[starbits]

To a boolit caster it makes no difference except that low alpha lead is much more expensive and if you had some that was verifyable you could sell it and buy a whole bunch more regular lead with it.

Lead which has been melted/smelted since the start of the nuclear age has a higher background radiation count thanks to the radiation added to the atmosphere. If you are a scientist measuring radiation that is near backgound levels you would want your sensor encased in material that has the lowest background levels possible so you could see the measurements easier. The low alpha lead fits the bill. Since lead which can be verified as not having been melted in the last 70 years is rare it is much more expensive.

Low alpha is pretty much just science applications, not industrial or casting.

Starbits

[lwknight]

Starbits nailed it.
Low alpha lead is required for portable scanning equipment so that even the tiniest bit
of radioactive material can be detected. Traces of low specific activity materials are hard to detect in a high background enviornment without the shielding.

[montana_charlie]

If a scientifically-minded person wanted a 'container' made of low alpha lead to protect some experimental activity, is it the case that he would have to assemble his container by cut-and-build, or by swageing?

I mean...he couldn't melt the lead and pour a new shape, right?

CM

[lwknight]

I have read that it can be cast in controlled conditions. Believe it or not , there are places inside the nuclear power plants and other labs that have almost no terrestrial radiation or contamination.
Monitoring stations inside the power plants use the cut/build method for remote monitoring stations and other monitoring equipment is brought in from labs intact.

JMO, but I think:

Lead ore from deep mines should be able to be refined in super controlled conditions as low alpha. It is costly because they cant just mass refine it like a mine smelter does.

Off topic but a little tid bit:
Terrestrial ionizing gamma radiation exposure to almost everyone on earth is about 250-300 millirems per year. Spending 50-60 hours a week inside the thick concrete walls of a nuclear power plant can actually protect people from the terrestrial radiation so that some nuke workers have lower doses than those who work outside.

We are exposed to radiation from everything like TVs radio towers, power lines, and even naturally occurring radon gas from the ground. The post nuclear era may have raised the above ground radiation slightly but it pales in light of man made high frequency magnetic fields everywhere and naturally occurring terrestrial radiation.