yomiuri.co.jp - March 28, 2012
The water level in the containment vessel of the No. 2 reactor at the Fukushima No. 1 nuclear power plant is only about 60 centimeters deep, far shallower than previously assumed levels of about four meters, according to Tokyo Electric Power Co.
The lower-than-expected water level was discovered for the first time when the power utility used an industrial endoscope to check the crippled reactor's interior on Monday, TEPCO said.
According to some experts, it is possible that nuclear fuel that melted through the reactor's pressure vessel and accumulated on the bottom of the containment vessel in the aftermath of the March 11 earthquake and tsunami may not be completely covered in the water.
TEPCO said the water temperature in the vessel remained relatively low within a range of 48.5 C to 50 C. The discovery of the unexpectedly shallow water level will not affect TEPCO's judgment that the reactor is in a state of "cold shutdown."