Tokyo Electric Power Co. workers reported temporarily detecting high levels of radioactive strontium in parts of a drainage ditch close to the ocean at the crippled Fukushima No. 1 nuclear power plant.
"The possibility that some of the contaminated water may have reached the ocean cannot be denied," a TEPCO official said.
The drainage ditch is used to remove rainwater. The high level of strontium was detected at a point about 150 meters from the water's edge.
Samples taken from the ditch on Sept. 11 registered 220 becquerels of beta ray sources, including strontium, per liter of water. No radioactive materials were detected in water sampled from the same area of the ditch a day later.
TEPCO workers had been decontaminating areas of the ditch upstream from where the samples were taken until Sept. 11. Radioactive cesium was also detected at a level of 104 becquerels per liter of water.
The area upstream from the ditch contains the storage tank that was found in August to have leaked 300 tons of highly radioactive water. It was also discovered that some of the contaminated water from the tank flowed into the drainage ditch.
TEPCO workers used pressurized water to clear away mud that had accumulated in the ditch on Sept. 11. It is believed that may have caused some of the radioactive material to flow further downstream.
Despite the cleanup efforts, strontium levels of 2,400 becquerels were registered in other areas around the ditch.
TEPCO officials believe the radioactive material is residue that was overlooked during the cleaning process. They say they plan to collect the remaining radioactive contaminated materials in the near future.
- « Prev
- Next »