After two months of stoppages and other problems, there are finally signs that efforts to purify highly radioactive water at the Fukushima No. 1 nuclear power plant are paying off.
After two months of stoppages and other problems, there are finally signs that efforts to purify highly radioactive water at the Fukushima No. 1 nuclear power plant are paying off.
Tokyo Electric Power Co., the plant's operator, said Aug. 3 that the system worked at 74 percent of capacity during the seven-day period through Aug. 2, up 16 percentage points from the preceding week.
The improved performance was the result of uninterrupted operations, officials said.
However, an influx of rainwater increased the amount of radioactive water at the plant.
TEPCO said 6,190 tons of radioactive water was treated between July 27 and Aug. 2, up 1,320 tons from the preceding week. This means that 120,770 tons of highly radioactive water remains at the power plant.
TEPCO said no reservoir water was pumped to cool the nuclear reactors. It said all the coolant water came from treated radioactive water.
Despite the accelerated treatment, rainwater was responsible for the increase in radioactive water. The figure rose by 120 tons compared to the previous week.
The purifying plant is designed to treat 50 tons of water per hour. The actual amount turned out to be 37 tons each hour.
Sludge has adhered to the piping that sends decontaminated water to temporary desalination tanks, thereby obstructing the flow.
TEPCO planned to install bypass piping on Aug. 4 and start treating water that evening at a target rate of 50 tons per hour. For this reason, TEPCO expects to achieve 90 percent capacity.