Technicians are battling to stabilise a third reactor at a quake-stricken Japanese nuclear plant, which has been rocked by a second blast in three days.
The Fukushima Daiichi plant’s operators have resumed pumping seawater into reactor 2 after a cooling system broke. They warned of a possible meltdown when the fuel rods became exposed after the pump stopped as its fuel ran out.
A cooling system breakdown preceded explosions at the plant’s reactor 3 on Monday and reactor 1 on Saturday.
BBC environmental correspondent Richard Black provides this analysis:
The fuel rod exposure at Fukushima Daiichi number 2 reactor is potentially the most serious event so far at the plant.
A local government official confirmed the fuel rods were at one point largely, if not totally exposed; but we do not know for how long.
Without coolant around the rods, temperatures can rise to hundreds of degrees Celsius, almost certainly resulting in some melting.
This opens the possibility of a serious meltdown – where molten, highly radioactive reactor core falls through the floor of the containment vessel and into the ground underneath.
However, engineers appear to have restored some water flow into the reactor vessel and if they are successful, temperatures will begin to fall again rapidly.