For the first time Japan has suggested the situation at the Fukushima nuclear plant has gone beyond a meltdown.
Japan says that nuclear fuel in three reactors has possibly melted through the pressure vessels and accumulated in the outer containment vessels.
Japanese media report this melt-through is far worse than a core meltdown and the worst possibility in a nuclear accident.
In a report to be submitted to the United Nations nuclear watchdog, Japan has also admitted it wasn't prepared for the scale of the Fukushima disaster.
Lateline - 08/06/2011: Fukushima escalates to worse-case possibility
Japan says that nuclear fuel in three reactors has possibly melted through the pressure vessels and accumulated in the outer containment vessels.
Japanese media report this melt-through is far worse than a core meltdown and the worst possibility in a nuclear accident.
In a report to be submitted to the United Nations nuclear watchdog, Japan has also admitted it wasn't prepared for the scale of the Fukushima disaster.
Lateline - 08/06/2011: Fukushima escalates to worse-case possibility
