60 cm, not 3 meters. What now ?

March 26, 2012

TEPCO: Just 60cm of water in Fukushima reactor

http://www3.nhk.or.jp/daily/english/20120326_34.html

Tokyo Electric Power Company says it has found that the cooling water in one of the damaged reactors at Fukushima is only 60 centimeters deep, far lower than previously thought.

The utility confirmed the water level by inserting an endoscope into the No.2 reactor at the Fukushima Daiichi nuclear power plant on Monday.

TEPCO had thought that the water level was about 3 meters. It has been injecting nearly 9 tons of water per hour into the reactor to cool the melted fuel that has fallen to the bottom of the containment vessel.

But the shallow level indicates that the water continues to leak into the reactor building through the suppression chambers under the vessel.

The utility argues that the fuel is still being cooled, as the water temperature remains at around 48 degrees Celsius.

But the low level suggests that decommissioning the reactor could be much more difficult. The operator may need to repair more parts of the containment vessel so it can be filled with water to block the strong radiation.

The No. 2 reactor's containment vessel is believed to have been damaged on March 15th with the sudden loss of pressure inside the reactor.

Monday's survey was the second look inside the No.2 reactor since January. During the first survey, an endoscope was unable to confirm the water level in the containment vessel. This time, TEPCO used a scope that is 10 meters longer.