[TheForge] Blacksmithing

[Andrew Vida]

James Binnion wrote:
> On Mar 16, 2011, at 1:37 PM, Andrew Vida wrote:
>> Uranium is a toxic heavy metal.  Metals such as it and Plutonium
>> would be hazardous even were they not radioactive.
> 
> As far as heavy metals go uranium is not as toxic as mercury or
> cadmium but there is that little problem of the radioactivity.

	As I understand, the radioactivity of U238 is not at all high... not 
that you want to go carrying a lump of it around in your pocket.  No, 
not as bad as plutonium, but still you do not want to be ingesting it in 
any quantities.  IIRC, and I may not be, the oxide is very toxic - sort 
of like berylium in that sense - metal is relatively innocuous compared 
with the oxide.

> Plutonium is in a way different class that stuff is very toxic.
> 
>> Forge uranium?  Not likely.  It is pyrophoric.  If you got that
>> thing burning, you'd be wishing you hadn't.
> 
> According to the literature it is hot worked but the heavy oxide
> formation makes the surface finish poor. 

	Again, my 30+ year memories on this may be in error, but I seem to 
recall something about such operations being carried out in inert gas 
atmospheres.

 > Just because it is
> pyrophoric does not mean you can't hot work it. Titanium and
> zirconium are pyrophoric and I have been doing a lot of hot work on
> them the past 4 years.

	I've done some forging of Ti as well.  Never managed to set it off, 
thankfully, but once going it's pretty hard to get it reined in.  Never 
worked Zr - sounds "interesting". :)


>> The buttons from which parts of the detonators are made have to
>> have the oxides removed after they are cast.  At least part of the
>> operation is done with hand scrapers.  It is good fun to watch the
>> sparks flying off as the scraping is done.
> 
> It is this type of action that is most likely to ignite these
> pyrophoric metals. They are poor thermal conductors the heat of
> cutting and the freshly exposed un-oxidized metal can go into very
> rapid oxidation (burn)

	In the case of 238 the combustion products are what would worry me the 
most.  As I recall, that was the really big deal at Chernobyl.  The 
graphite core burned, taking the fuel with it into a fine, horrifically 
poisonous and radioactive soot that flew all the way to Lapland. 
Remember all those helicopter pilots dumping concrete on top of the 
reactor building?  Every last one died of radiation sickness.  Hot hot 
hot...  Tons of the people from Chernobyl died of cancers just a few 
years after evacuation.  It was a terrible cluster copulation.  That is 
the problem I have with this form of energy - designs, construction, and 
operations are all high-tolerance affairs.  The conflicting interest of 
the profit motive makes for terrible risks.  Too terrible to mess with, 
IMO.  I well understand that living in a technological culture exposes 
us to certain risks, but those posed by this particular technology seem 
unreasonably high.  The chances of this happening were vanishingly 
small, yet it happened and the consequences could remain for a very long 
time depending on how things turn out.  If my children were exposed to 
such things, I'd be REALLY pissed.