http://www3.nhk.or.jp/daily/english/20120628_01.html
Jun. 27, 2012 - Updated 23:46 UTC
The highest level of radiation to date has been detected inside the No.1 reactor vessel at the Fukushima Daiichi nuclear power plant.
Tokyo Electric Power Company said it used endoscopes and dosimeters to examine the interior of the reactor on Tuesday. Internal measurements were made for the first time since the accident in March last year.
The utility detected a record level of 10,300 millisieverts per hour. 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. No broken parts were identified in the containment vessel during the survey.