To prevent a further contamination of the sea as occurred in December, Tokyo Electric Power Co. plans to remove about 1,000 kinds of radioactive materials from water at the crippled Fukushima No. 1 nuclear power plant, sources said on Jan. 28.
To prevent a further contamination of the sea as occurred in December, Tokyo Electric Power Co. plans to remove about 1,000 kinds of radioactive materials from water at the crippled Fukushima No. 1 nuclear power plant, sources said on Jan. 28.
The utility will start installing equipment in March for the removal of the radioactive materials, including not only cesium, but also strontium, cobalt and manganese, the sources added.
According to the sources, TEPCO is currently purifying contaminated water by using two kinds of devices in which a mineral, zeolite, absorbs cesium. However, those devices cannot remove other radioactive materials, such as strontium.
In December, contaminated water containing strontium whose concentration level was 1 million times higher than the government’s safety standard leaked into the sea, though the cesium had been removed.
To prevent the recurrence of a similar leakage, TEPCO decided to remove more kinds of radioactive materials. In the plan, water and waste liquids that were used to absorb cesium will be further purified by new equipment.
The design of the new equipment has yet to be decided. In the device, however, radioactive materials will be absorbed onto the surfaces of minerals or resins. By using a variety of agents that promote absorption, the utility plans to remove various radioactive substances.
In the Fukushima No. 1 nuclear plant, contaminated water that was apparently injected into nuclear reactors to help cool them are flowing into buildings in the compound. The amount ranges from 200 tons to 500 tons per day.
To process the water without delay, the new equipment will have the ability of purifying about 500 tons a day. Minerals and resins that absorbed radioactive materials will be placed into special bags and dehydrated. Then, they will be stored for about 20 years.
The new equipment will not be able to remove radioactive hydrogen, called tritium. However, concentration levels of most other radioactive materials will become much lower than the government’s safety standards after the contaminated water is purified by the new equipment.
Initially, TEPCO considered discharging the water into the sea after purifying it. But it faced strong opposition from the central and local governments to the plan.
In addition, the utility’s in-house rules on the safety management of the Fukushima No. 1 nuclear power plant read, “Water that was used to process contaminated water must not be discharged (into the sea) without the approval of ministries and agencies concerned.”
Therefore, the means of disposing of the purified water has yet to be decided.