Is graphite itself radioactive or graphite mixed with oxygen? or is it just when graphite is burning?

Question

I'm talking about the second explosion in the nuclear reactor from the 1986 Chornobyl accident.

Answer 1

What makes you think that graphite is radioactive?    In fact, none of the explosions at Chernobyl were of a "nuclear" nature.  

Graphite is carbon, and like coal, it will burn.  The Russian reactors use graphite as a moderator instead of water, as US reactors do.  If graphite gets too hot it will burn.

The plant operators were conducting a "test" that went "horribly wrong".  There was a massive build-up of heat that superheated the cooling water causing a steam explosion that demolished the top of the reactor and exposed the core, emitting radioactivity and ignited the graphite.  The explosions were steam explosions, not "nuclear explosions".

Answer 2

The graphite wasn't radioactive.  Graphite is an allotropic form of carbon, typically used as a reactor moderator as it has a pretty good neutron capture cross-section.

The radioactivity released came from the reactor core, which was breached.  The radioactive materials mixed with the other materials in the breached core.  Then the graphite caught fire, and that fire aerosolized the contamination from the ruptured core.  And all that heavy radioactive contamination was dispersed in the smoke plume, to settle out of the airstream miles away.

Answer 3

Graphite is pure form of Carbon, like the Diamond, but it being of different structure, is used as a high temperature Lubricant.

Its pure form of carbon, when burnt in oxygen will produde CO2 and CO.

I am not sure about the causes of explosion, but this is what it might be used in a reactor- high temp. lubricant.

Answer 4

The reactor vessel was made out of graphite.

Graphite is not radioactive, nor is it radioactive when it's burning.  The radiation problem came from the reactor blowing apart in the explosion.  The inside of a reactor core is *extremely* radioactive.  When the reactor exploded, the contents of the core were no longer contained.