"Tokyo Electric Power Co. started the unprecedented and potentially risky measure of allowing water to flood the containment vessels of three troubled reactors at the Fukushima No. 1 nuclear power plant, company sources said.
It is the world's first attempt to saturate the entire containment vessel with water with the aim of cooling the pressure vessels inside the containment vessels and ultimately the reactor cores themselves.
So far, TEPCO has been injecting water into the pressure vessels at the No. 1 through No. 3 reactors. Under the new plan, TEPCO will allow the water to overflow from the pressure vessels through valves and ruptured pipes until the water fills the outer containment vessels.
According to TEPCO's road map, the water levels will reach the upper end of the fuel rods within three months. "