Talk:Low-background steel

Metalworking Low‑importance

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Materials Low‑importance

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Why is it not contaminated?

Who created Low-Background steel?

Also how come it is not contaminated during re-smelting when recycled? — Preceding unsigned comment added by 77.86.117.208 (talk) 09:57, 9 October 2016 (UTC)[reply]

They don't remelt the metal. Instead they just cut the old ship plating to the shapes and sizes needed to build for instance a whole-body counting machine box. They then ~~weld~~/put the pieces together. I have been scanned in such a box here in Sweden: The whole box was about 2x2x2 meters. Just enough to fit the machine and the bed. Also the door was made from the ship plating. The door and walls of the box was about 10 cm (4 inches) thick. So the whole thing looked like a really big safe.

The scanning technician mentioned that to reduce radiation as much as possible the plating came from an old warship that had been sunk long ago, and after the plating was salvaged the plating was never stored outdoors to not expose it to radiation.

The machine was placed in the cellar of the hospital. I don't know if that was due to the weight of the box or to further reduce background radiation.

--David Göthberg (talk) 14:17, 31 January 2020 (UTC)[reply]

It's even difficult to weld the plates, as the welding rods have post-war contamination issues too. Also such counting boxes don't need to be structurally strong, but they do need to be portable for construction. So the edges are often flame cut and ground to some sort of simple interlocking shape (this also avoids beam leaks through any straight gaps). The main strength is from a girder frame on the outside. After shaping, the surface (especially any flame-cut edges) are grit-blasted to remove surface contamination. Andy Dingley (talk) 14:27, 31 January 2020 (UTC)[reply]

Ah thanks, I didn't know that. I love this kind of technical details. --David Göthberg (talk) 15:07, 31 January 2020 (UTC)[reply]

also needed

Cobalt 60 contamination from the lining of cauldrons as mentioned https://www.good.is/articles/the-search-for-low-background-steel which also mentions low background lead which is very important for gamma ray spectrometers (amongst other uses). — Preceding unsigned comment added by 101.100.130.127 (talk) 20:09, 3 March 2020 (UTC)[reply]