Damage to the interior of a structure at Fukushima No. A nuclear power plant can be seen in a photo released by Tokyo Electric Power Company Holdings, Inc. on Wednesday.
The image shows the interior of the pedestal, a cylindrical reinforced concrete base supporting the reactor pressure vessel of the No. power plant. 1 reactor. Part of the pedestal's inner wall can be seen to have melted away, exposing its rebar.
The image was taken by a remotely controlled underwater robot on Tuesday. The concrete may have been damaged by the heat from the melted-down nuclear fuel during the March 11, 2011 nuclear disaster.
The pedestal has an interior diameter of about 5 meters, and the concrete is about 1.2 meters thick. During the last year's survey, it was confirmed that the outer wall near the pedestal's inspection doorway was melted, but the interior of the pedestal was not visible. An underwater robot camera was pointed at the interior from the entrance. On the floor of the interior was sedimentary debris that was believed to include nuclear fuel debris.
TEPCO is now photographing the entire interior wall of the pedestal using the underwater robot to determine whether the concrete is damaged and lacks earthquake-resistant strength. The camera will be turned upward to see the bottom of the reactor pressure vessel.