Fukushima plant's undersea radiation-containment curtain ripped
TOKYO (Kyodo) -- Damage was found Thursday on one of the undersea curtains installed near the crippled Fukushima Daiichi nuclear power plant to help contain radiation contamination, plant operator Tokyo Electric Power Co. said.
The curtain, called a "silt fence," is placed around an adjoining pair of water intakes of the plant's Nos. 5 and 6 reactors, which did not suffer meltdowns during the 2011 Fukushima nuclear disaster.
A worker found a cut in the fence at about 10:40 a.m., TEPCO said without elaborating, adding it is studying the damage and its impact. A cut had also been found in April.
As waves are high due to a typhoon moving near the Japanese archipelago, the utility said it plans to repair the barrier after the weather becomes calm.
The silt fence consists of cloth hung from buoys in the sea with weights and is installed around a set of intakes of the Nos. 1 to 4 units, which suffered critical damage during the nuclear crisis, as well as another set of intakes of the Nos. 5 and 6 reactors.
The fence cannot completely block radioactive substances but is seen to be effective in preventing contaminated soil on the seafloor from spreading.
The seawater in front of the Nos. 1 to 4 units is more contaminated than that in front of the Nos. 5 and 6 units. The silt fence for the Nos. 5 and 6 units is intended to prevent the water enclosed there from becoming further contaminated by getting mixed with more toxic water.
The seawater in front of the Nos. 5 and 6 intakes is discharged into the Pacific Ocean after cooling the two reactors, meaning that the water in the area needs to be kept clean as much as possible.
Facing growing concerns over the plant operator's lax handling of a massive amount of radioactive water at the plant, Prime Minister Shinzo Abe has said that the situation is "under control" and that the influence of toxic water "is completely blocked within the 0.3 square-kilometer area of the plant's port."
The silt fences exist inside the port breakwaters.
To mitigate the impact of possible water leaks from the plant, TEPCO plans to greatly reduce the radiation level of 300,000 tons of highly toxic water it is currently keeping in tanks at the plant's premises by the end of March 2015.
The key to the plan is the operation of a facility that can remove various radioactive substances from the contaminated water, with the exception of tritium.
The facility, called the advanced liquid processing system, has three processing lines, each of which can handle 250 tons per day of water. TEPCO plans to start on Friday the trial operation of one of the lines using the actual contaminated water.
September 26, 2013(Mainichi Japan)