TOKYO: One of Japan's crippled nuclear reactors still has fatally high radiation levels and hardly any water to cool its fuel, according to an internal examination that reinforces doubts about the plant's stability.

A tool equipped with a tiny video camera, a thermometer, a dosimeter and a water gauge was used to assess damage inside the No. 2 reactor's containment chamber Tuesday for the second time since the tsunami swept into the Fukushima Dai-ichi plant a year ago.

The data collected showed the damage from the disaster is so severe, the plant operator will have to develop special equipment and technology to tolerate the harsh environment and decommission the plant, a process expected to last decades.—AP