endoscope to examine the inside of a containment vessel of the damaged No. 2 reactor

Preparations are under way to use an endoscope to examine the inside of a containment vessel of the damaged No. 2 reactor at the Fukushima Daiichi nuclear power plant.At the No.1, 2, and 3 reactors of the plant, the nuclear fuel has melted down, but the exact state of the fuel and details of the inside of the containment vessels are yet to be confirmed. This is causing a big problem for the operator, Tokyo Electric Power Company, in its continued efforts to stabilize the cooling of the reactors and its plans to decommission them. The reactors were damaged by the March 11th earthquake and tsunami.On Tuesday, 10 groups of 4 workers each entered the first floor of the No.2 reactor building from the northwestern side. The workers drilled a hole in the containment vessel to insert an endoscope. An industrial endoscope that can withstand high levels of radiation will be used.The utility says the workers were exposed to up to 3 millisieverts of radiation. The company says the workers had rehearsed the job at the No. 5 reactor, the same type as the No.2, in order to minimize their exposure.TEPCO says Tuesday's operation went smoothly and it will insert the endoscope on Thursday as scheduled. It hopes to gain the first internal view of one of the damaged reactors since the accident.