NEI Nuclear Notes

You may have noticed some talk flowing around the great chatter box that is the Internet about recriticality at the reactors at Fukushima. …Now there is definitive proof, courtesy of Tellurium 129 and a order of magnitude higher concentration of Iodine 131 in Reactor 1, that the reactor is now undergoing sporadic events of recriticality… Simply put, recriticality means that a reactor has become critical again and reentered the fission process. But finding tellurium-129 in water in the turbine building of the reactor is hardly the smoking gun of recriticality that “Tyler Durden” would have you believe. It is evidence of criticality, to be sure, but not re-criticality. In fact, it is evidence of past criticality at the reactor. In this case—if the reading turns out to be accurate—it could be evidence of criticality before the earthquake on March 11 when the reactor was operating normally and was, well, critical. Here is NEI’s own Rodney McCullum with a technical explanation: The de...