The highest level of radiation to date has been detected inside the No.1 reactor at the tsunami-wrecked Fukushima Daiichi nuclear power plant in Japan.
The plant’s operator Tokyo Electric Power Company (TEPCO) said on Thursday it used endoscopes and dosimeters to examine the interior of the reactor. A record level of 10,300 millisieverts per hour was detected in the internal measurement carried out for the first time since the March, 2011 accident. The measurement was taken 20 centimeters above the surface of a contaminated water puddle in the reactor’s suppression chamber. This high level of radiation would be fatal for humans within 50 minutes.
A measurement of 1,000 millisieverts per hour was detected about four meters above the water surface, which is ten times higher than measured in the No.2 and No.3 reactors, Japanese media reported.
TEPCO official Junichi Matsumoto said he suspected that a higher radiation level in the No.1 reactor was caused by more fuel rods melting down than in other reactors.
He said robots would be used for damage assessment because it was unsafe for humans to work on the site.
Meanwhile, Officials from the Nuclear and Industrial Safety Agency apologized to Kawauchi village mayor Yuko Endo and communities around the plant for failing to release maps showing dangerous radiation areas. Residents of the village were forced to evacuate after the government designated 20-kilometer radius of the plant as no-entry zone.
The maps were provided by the United States days after the tsunami-triggered accident. U.S. Energy Department scientists used aerial surveys to compile the maps showing the spread of radiation around the stricken plant. The information was given to the Japanese Education and Science Ministry and the Nuclear and Industrial Safety Agency, the country’s nuclear watchdog, through the Foreign Ministry.The mayor said if the information were given to the village, people could have avoided evacuating into areas of high radiation. He also said more than a year has passed since the accident, and the apology meant nothing.