While the greatest risk may have passed at the Fukushima Daiichi nuclear power plant, the news is still bad. The operator, Tepco, now says it is likely that reactor 1 probably had a complete meltdown within a day or so after the tsunami struck. In the best case, this means that all the radioactive metal is sitting in a lump, or puddle, at the bottom of the reactor. All Things Nuclear examines this scenario and points out that it implies at least five more years of ad hoc cooling before the nuclear fuel decays enough to consider moving it. On the other hand, some engineers who have examined the public statements say the heat readings are too low for a full meltdown, which could mean that some or all of the nuclear fuel has escaped the reactor vessel. If it did, no one knows exactly where it is. We can be pretty sure the reactor vessel is broken because water pumped in isn’t filling up the vessel. A total meltdown in reactor 1 is bad enough, but Tepco says it is possible that the same thing has happened in reactors 2 and 3.
Tepco’s financial condition is worrisome in itself. It reported a $15 billion loss for the year, the largest ever for a Japanese corporation outside of banking. Its president resigned on Friday. Politicians are arguing over its shape for the near future, something the company itself will have very little say in. Tepco needs to show competent management of the nuclear crisis at Fukushima, as that is surely the only thing to save it from liquidation.