A key system to treat highly radioactive water at the Fukushima No. 1 nuclear power plant is operating below its target, threatening to delay the year-end goal for treating all the accumulated water.
A key system to treat highly radioactive water at the Fukushima No. 1 nuclear power plant is operating below its target, threatening to delay the year-end goal for treating all the accumulated water.
The system operated at about 76 percent its daily maximum capacity of 1,200 tons between June 29 and July 5, falling short of the 80 percent target, Tokyo Electric Power Co., the plant's operator, said July 6.
The capacity utilization rate improved from about 55 percent between June 17 and 28, but the system was stopped three times on June 29 and 30 due to water leaks and other problems, reducing the amount of water treated.
About 119,000 tons of radioactive water was accumulated at the reactor buildings and elsewhere at the Fukushima plant as of July 5, about 1,700 tons less than a week earlier.
About 14,970 tons of radioactive water has been treated since the system started up June 17.
Of that amount, 5,450 tons was desalinated to be pumped into reactors. TEPCO began using the treated water to cool reactors on June 27.
TEPCO plans to raise the capacity utilization rate to 80 percent in July and 90 percent in August.
"We want to operate the system with greater stability and raise the capacity utilization rate by preventing problems," Junichi Matsumoto, acting general manager of TEPCO's Nuclear Power and Plant Siting Division, said. "But further delays are possible, depending on operations."
TEPCO on July 6 closed a valve leading to a spent nuclear fuel storage pool for the No. 4 reactor and hopes to restore the pool's cooling system later this month.
The company also checked piping and measured radiation levels in the No. 3 reactor building with robots, in preparation for steps to inject nitrogen to prevent hydrogen explosions.