– Endoscope fails to reach water at Fukushima reactor (Asahi Shimbun, Jan. 19, 2012):
A remote-controlled endoscope with a thermometer showed the temperature inside the No. 2 reactor of the crippled Fukushima No. 1 nuclear power plant on Jan. 19 was about 45 degrees, Tokyo Electric Power Co. said.
But the endoscope lens became covered in water droplets and the reception was sometimes fuzzy, so the operator of the plant could not determine the condition of the melted fuel or if the pipes were damaged.
In addition, the endoscope, 8.5 millimeters in diameter, did not reach the surface of the water.
TEPCO had predicted the water level would be 4.5 meters based on the pressure level in the containment vessel.
But after about an hour of operation using the endoscope, TEPCO said the actual water level was probably about 4 meters or lower.
“The pressure level we used for our prediction must have been wrong,” a TEPCO official said, adding that he doubted the lower level was caused by a heavy leakage of water.
It was the first time TEPCO has directly investigated inside the containment vessel of a reactor at the plant since the nuclear accident started on March 11.
TEPCO plans to use the latest observations with the endoscope to confirm the reactor has entered a stable “cold shutdown” stage ahead of work to decommission the damaged reactors.