Workers enter containment vessel at Fukushima Daini reactor

The group of about 10 workers will check the radiation levels and other conditions inside the vessel of the reactor, which automatically halted operations after the magnitude 9.0 temblor.

It will be the first time since the disaster that workers have entered containment vessels at either the Daini plant or TEPCO's other nuclear plant in Fukushima Prefecture, the crippled Daiichi plant located about 10 kilometers north.

Among Fukushima Daini's four reactors, the No 4 reactor was the first to successfully have its cooling systems activated in the aftermath of the quake. In addition, gauges at the reactor show no abnormalities at present, prompting TEPCO to decide to conduct the inspections today.

The utility said it also plans to send workers into the containment vessels of the other three reactors at the Fukushima Daini plant in the near future.

All four reactors at Fukushima Daini have been brought into a stable condition called "cold shutdown" following the March disaster.

Meanwhile at Fukushima Daiichi's No 2 reactor, a thermometer located on the upper part of the pressure vessel showed a rapid rise in temperature to 120 C today, up from 72 C yesterday.

But TEPCO said the reading was likely due to malfunctioning of the thermometer, as other thermometers and barometers showed no abnormalities inside the vessel.
The thermometer in question is located close to a cover which serves as the opening when removing fuel from the vessel.