Fukushima N-plant struggles continue

FUKUSHIMA - Water contaminated with radioactive substances continues to flow into the basement level, while the collection of spent nuclear fuel rods is progressing steadily at the No. 4 reactor of Tokyo Electric Power Co.'s Fukushima No. 1 nuclear power plant. That was the situation, due chiefly to the absence of any decisive countermeasures, when we visited on Wednesday.

When the Great East Japan Earthquake occurred on March 11, 2011, the No. 4 reactor was not operating, having been suspended for regular checkups. Therefore, the radiation level inside that reactor still remains lower than those at the plant's Nos. 1 to 3 reactors where the core meltdowns occurred.

However, the contaminated water still continues flowing into the No. 4 reactor from the adjacent No. 3 reactor via pipes and other routes. We went down to the basement level for the first news coverage from the spot. The radiation level in the area measured 10 to 12 microsieverts per hour, which would add up to one millisievert in a matter of four days-the level that an ordinary person is estimated to be exposed to in a year.

We walked on the scaffold above a pressure suppression chamber, a part of the reactor container.

As we walked around above the doughnut-shaped suppression chamber, we shone our flashlights underfoot, to find green, turbid water about 2 to 3 meters below.

We also entered a reactor containment vessel for the first time. Pipes and walls there were heavily damaged. Debris scattered after the hydrogen explosions three years ago was also left untouched on most floors of the building. Bare pipes and reinforcing bars hung down from the walls, showing the extent of the devastation inside the building.

In contrast to these, the damaged walls and ceiling were removed and replaced by covers on the top floor of the building where the work to collect spent nuclear fuel rods was under way.

Using a new crane that replaced the old one, workers were collecting the fuel rods one by one and putting them into a special container, while monitoring progress on a computer screen. About 330 of the 1,533 fuel rods had already been taken out. Everything appeared to be in order there, as if nothing had ever happened.

About 400 meters from the No. 4 reactor building is an area crowded with tanks to store the contaminated water. As a crack was found in the concrete base there on Tuesday, workers had filled the crack with resin.

Construction of frozen soil walls to prevent groundwater from mixing with the contaminated water has not started, as technical tests are still under way.

As the decommissioning of damaged reactors is said to take as long as 40 years to complete, there is still a long way to go. We strongly feel that effort, to be made by the whole nation, is needed.