I am betting that it is a matter of time before we hear that in fact Plutonium has leaked out of Reactor 3 at Fukushima Dai-ichi. The Time blog reported on a potential breach in the reactor containment vessel, and I heard a similar report on CNN today.
Hidehiko Nishiyama, deputy director-general of the Japan Nuclear and Industrial Safety Agency, said at a news conference that a reactor vessel of the No. 3 unit may have been damaged. That raises the possibility that radiation from the MOX fuel in the reactor — a combination of uranium and plutonium — could be released. The three workers who suffered skin burns were working on the No. 3 reactor, which is one of the clues that the vessel may have been damaged.
As a matter of fact, unless the situation is improved markedly two more weeks of radiation leaks would place this at a level similar to Chernobyl. Reuters reported:
Based on measurements made at monitoring stations in Japan and the United States, Wotawa said the iodine released from Fukushima in the first three-four days was about 20 percent of that released from Chernobyl during a ten-day period.
For Caesium-137, the figure could amount to some 50 percent.
This means that the levels of the longer lasting Cesium 137 isotope are already potentially 50% of Chernobyl, and the situation is not over yet. Japan has pegged this at a Level 5 Nuclear disaster, I am betting that the scale of the problem will be raised to a Level 6 nuclear disaster in the coming week, making it worse than Three Mile Island and only second in severity to Chernobyl. I read today a report which I will try to find again that pegged the amount of escaped radiation and the area affected make it a Level 6.