On 4/15/2011 8:50 PM, Darren New wrote:
> On 4/15/2011 19:57, Patrick Elliott wrote:
>> The problem isn't nuclear explosions, its hydrogen generated by the
>> system,
>
> Are you talking about the alpha radiation or something? I can't imagine
> where hydrogen would come from unless they're cracking water or something.
>
As I understand it, with the reactors in question, the rods are stored 
in a "casing", which can resist the heat of a normal reactor, but.. and 
I may be incorrect with this, when they get hot enough to start 
corroding/failing, they either release hydrogen themselves. Right, 
confirmed from the a news link on it: "When the fuel rods are left 
uncovered by water, they'll get far too hot--we're talking thousands of 
degrees Celsius here--and begin to oxidize, or rust. That oxidation will 
react with the water that's left, producing highly explosive hydrogen gas."

So, the "steam" that breaches the containment on these isn't just steam, 
its hydrogen gas, which gets released at those excess temperatures. 
While some is produced during normal operation, its small, and easily 
dealt with. So.. Its not just a case of it getting real hot, and the 
water boiling off. You have *that* problem, then due to the construction 
of the rods/casings, you *also* produce a gas that is both a) expanding 
into the chamber, which can breach it, and b) extremely flammable, if 
air can mix into it at all, through say, a large enough crack, when 
combined with some ignition source.

All in all, a bad design, since any failure doesn't just create a known, 
and easy to deal with problem, i.e., getting it cool again, it escalates 
and produces even *more* problems, which turn a non-explosive system 
into one that emits flammable materials. Its sort of like building a car 
so that, if you hit something, the rear seat pops loose and hurls all 
the trunk contents into the passenger cab as well.

Post a reply to this message