Neutron radiation bursts have been measured remotely 13 times eminating from the Fukushima plant, indicating possible sub criticality events (Possible Plutonium Fizzles due to cooled gas deposit build ups??) have been constantly reoccurring.

I don't think we have yet seen the worst. Lets hope we don't have a 1/2 critical mass of Plutonium i.e. a Plutonium stalactite falling into another 1/2 critical mass of pool of molten Plutonium.