# Radioactivity and Modern Metals **URL:** \ **Category:** Factual Questions\ **Created:** [February 16, 2008, 3:13pm UTC](https://boards.straightdope.com/t/radioactivity-and-modern-metals/437883 "2008-02-16T15:13:37Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [February 16, 2008, 3:13pm UTC](https://boards.straightdope.com/t/radioactivity-and-modern-metals/437883/1 "2008-02-16T15:13:37Z")
[According to this story, pre-WWII metal is highly prized because of it’s lack of radioactivity.](http://scienceblogs.com/highlyallochthonous/2008/02/battleships_in_space.php) > [@](#): > > As a result, for some applications, such as making sensitive measurements of radioactivity (for example, shielding whole body counters for measuring radioactive exposure), old steel is _much_ better than new. > > One of the best sources of this venerable and increasingly rare material is, bizarrely enough, sunken warships. A particularly good source is the sunken remnants of the German Imperial Fleet, which was interned at Scapa Flow in the Orkney Isles following the German surrender at the end of the WWI. Most of the ships were eventually scuttled by their German crews to keep them out of enemy hands, and although salavage and decay have taken their toll, there are still several large chunks of ‘pre-atomic’ steel within easy reach beneath the shallow waters of Scapa. Now this, especially the part about carving up wrecks of the German Navy, sets my BS meter off. I can’t imagine that this would be in any way economical, compared to taking precautions with modern metals to keep out atmospheric contaminations (which you’d have to do _anyway_, when you melted the old stuff down). Of course, I’ve been wrong before, so is this, in fact, accurate? Or just another urban legend? ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [February 16, 2008, 3:22pm UTC](https://boards.straightdope.com/t/radioactivity-and-modern-metals/437883/2 "2008-02-16T15:22:58Z")
The old steel story probably stems from this 1988 article in the **Journal of Radioanalytical and Nuclear Chemistry** : [Utilization of steel plates from abolished old metallurgical factory for shielding of low activity measurement devices](http://www.springerlink.com/content/p1v885267195404m/) ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [February 16, 2008, 3:38pm UTC](https://boards.straightdope.com/t/radioactivity-and-modern-metals/437883/3 "2008-02-16T15:38:18Z")
The way I heard the story makes more sense. Since 1945, the large number of atmospheric nuclear tests have introduced relatively large amounts of radioactive isotopes of various elements into the atmosphere. If you try to smelt steel these days, even from ore, you’ll still end up with some radioactivity in the finished product, due to things like radioactive oxygen, carbon, etc… in the air. These isotopes can be separated out, but it’s a project similar in concept to enrichment of uranium, except in reverse. Why go to all that trouble, if you can go get high quality steel from a relatively shallow depth that is known to be free of any radioactivity? That’s why they use these uboats that were sunk off the British coast in various places after WWII. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [February 16, 2008, 4:04pm UTC](https://boards.straightdope.com/t/radioactivity-and-modern-metals/437883/4 "2008-02-16T16:04:04Z")
[QUOTE=bump] Why go to all that trouble, if you can go get high quality steel from a relatively shallow depth that is known to be free of any radioactivity? [/QUOTE] It won’t be free of “any” radioactivity - it will simply have less. There was background radiation before the 1940’s, you know. I could see this being worth the effort for very specialized applications, but not for most purposes. ---
**Author:** ![chrisk](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@chrisk](https://boards.straightdope.com/u/chrisk)\ **Post date:** [February 16, 2008, 4:13pm UTC](https://boards.straightdope.com/t/radioactivity-and-modern-metals/437883/5 "2008-02-16T16:13:02Z")
[QUOTE=bump] If you try to smelt steel these days, even from ore, you’ll still end up with some radioactivity in the finished product, due to things like radioactive oxygen, carbon, etc… in the air. These isotopes can be separated out, but it’s a project similar in concept to enrichment of uranium, except in reverse. [/QUOTE] Nothing to add to the steel discussion, but reference to seperating out oxygen isotopes reminded me of an idea that occured to me from an old Isaac Asimov story, ‘pate de foie gras’: “How difficult would it be to keep a goose alive while keeping it from metabolizing anything containing O18 - from the air, from the water it drinks, and from its food?” 😃 As an aside, I doubt that there’s really any meaningful concentration of ‘radioactive oxygen’ in our environment, considering that the longest-lived unstable oxygen isotope, O15, has a halflife of a little bit over 2 minutes. A far cry from radiocarbon decay 🙂 ---
**Author:** ![Precambrianmollusc](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/precambrianmollusc/32/63_2.png) [@Precambrianmollusc](https://boards.straightdope.com/u/Precambrianmollusc)\ **Post date:** [February 17, 2008, 4:26pm UTC](https://boards.straightdope.com/t/radioactivity-and-modern-metals/437883/6 "2008-02-17T16:26:27Z")
FWIW a personal story I worked for a year with the UK Atomic Energy Authority in a lab where we were monitoring ultra low level decommisioning waste. A very sensitive germanium crystal gamma ray spectrometer was used. This device was surrounded by lead bricks and cadmium plates. The structural frame was built from steel from pre world war 2 ships. The reason given was that due to all air burst weapons tests, modern steels are of no use. Whilst the detector could descriminate between isotopes, most of the contamination was of the same isotopes as we were looking for on the waste. So yes, this is true. NBC