Technicians succeeded in introducing sea water to one of the quake-stricken nuclear reactors in north-eastern Japan Monday, as an emergency measure to cool the core, reported DPA
The fuel rodes of reactor 2 at the Fukushima I plant were fully exposed briefly Monday, as the level of cooling water fell after Friday's magnitude-9 earthquake and tsunami cut the power to the normal cooling systems.
Late Monday, Kyodo reported that around 30 centimetres of water had been reintroduced to the overheating core.
Fears were increasing that temperatures in the core could rise to a level where the rods could melt their way through the core's steel walls, an event known as a meltdown.
If the containment structure around the core has been cracked by the quake, a meltdown could cause radiation to leak into the surrounding environment.