Tepco is reporting Xenon gas is being detected at Fukushima around reactor 2.
Xenon's short half-life makes it a good indicator of fission.
see also http://www.washingtonsblog.com/2012/02/fukushima-reactor-temperature-surpasses-752-degrees-more-than-4-times-maximum-for-cold-shutdown.html
Several months ago I posted about types of criticality: Nuclear Chain Reactions and Forms of Criticality http://majiasblog.blogspot.com/2011/11/nuclear-chain-reactions-and-forms-of.html
It seems clear that there is enough corium somewhere in unit 2 to produce a geometry of melted fuel enabling fission to occur.
The fission may simply start and stop again, or it may produce a critical chain capable of ending in an explosion.
Either way, the fission is releasing more radiation into the atmosphere, poisoning our planet.
A commentator at Enenews explained briefly what may be happening. I found his comments instructive:
– They are not thermal reactors any more, no moderator exists within the fuel masses.
These masses are piles of hot goo w/ fast neutrons activating U-238 as well as U-235 and Plutonium.
– Chain reactions create Xe-135 which is a strong neutron poison.
– The Xe-135 slows the chain reaction until it is 'burned up' (has absorbed as many neutrons as it can) then the chain reactions start up again creating more Xenon.
– There is Xenon-135 AND increasing chain reaction there is BIG PROBLEM as the chain reaction can run-away without the Xenon being able to poison it.
Because there is Xenon there is a chain reaction taking place, this is also indicated by the large amounts of steam inside the building and the increase in temperature.
– It is possible/likely there is a critical mass of fertile material inside the reactor that cannot be reached by water or boric acid. If this is so, the hope is for the material to cool itself by magic.
The next hope is for the fuel to reconfigure itself without violent explosion taking away the reactor building, the other cores and all that spent fuel. [end quote]
Majia Here: Steve's comments reinforce the cataclysmic nature of the ongoing Fukushima disaster. And yet, the disaster is barely whispered in the mainstream press.
Our inability to look beyond what is in front of our faces is truly terrifying because our myopic self-absorption allows inept and greedy interests to control situations that threaten humanity itself.