Posted By: vitas (vitas) on 'CZscience'
Title:     Re: Obnovitelne zdroje, cista energie
Date:      Thu Apr 20 13:26:24 2006

Ahoj,
> > Nevyrabeji se jaderne hlavice z plutonia, ktere je "odpadem" z elektraren?
> > Hm, jak tak koukam do wikipedie tak je pravda ze se da pouzit i U235
> > http://en.wikipedia.org/wiki/Nuclear_weapon_design , otazka z ceho jsou 
> > vyrobeny ty kterych maji USA a Rusko 3x ... spoustu. 
> 
> Co si pamatuju, co bylo ve zpravach, tak pro elektrarny musi byt uran
> obohacen 
> o izotop 235 neco kolem 5% a pro jaderne zbrane to bylo o dost vice, ted 
> nevim presne kolik (30%?).

Cituji z vyse uvedeneho odkazu: 

Uranium which is more than 20% U-235 is called highly enriched uranium (HEU), 
and weapons grade uranium is at least 93.5% U-235. U-235 has a spontaneous 
fission rate of 0.16 fissions/s-kg. which is low enough to make super 
critical assembly relatively easy. The critical mass for an unreflected 
sphere of U-235 is about 50 kg, which is a sphere with a diameter of 17 cm. 
The critical size can be reduced to about 15 kg with the use of a neutron 
reflector surrounding the sphere.

Nebo-li: ten uran z hlavic by se asi musel ochuzovat nez by se dal do 
elektrarny, coz ale urcite zdaleka neni tak tezke jako ho na takovouto 
hodnotu obohatit.

vitas
  @;; 

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