NARAHA, FUKUSHIMA PREF. – Tokyo Electric Power Co. said some 20,000 tons of radioactive water at the Fukushima No. 1 nuclear plant will be left untreated as of May, missing its cleanup target.
Tepco cited the presence of relatively high levels of seawater-derived substances, including magnesium, and therefore it will take several more months to treat that portion of the contaminated water. The affected water represents 3 percent of the 600,000 tons of tainted water stored at the plant.
The rest of the contaminated water is expected to be treated by that month using either the Advanced Liquid Processing System, or ALPS, which can drastically reduce levels of 62 radioactive substances, or another system capable of removing strontium-90, a radioactive isotope that is particularly harmful for human health.
Tepco presented the estimates at a meeting Monday with the government held in Naraha, Fukushima Prefecture.
The plant operator initially targeted completion of the treatment of all radioactive water by the end of this month, but it pushed back the deadline to May due to a lower than anticipated running rate of the ALPS system.
Tepco will show later how long the water cleanup work will be prolonged, a senior company official told reporters after the meeting.
Also at the meeting, Tepco said it will likely be able to start freezing soil around the four shattered reactor buildings in April. The utility hopes to form an underground ice wall to block the inflow of groundwater into the facilities’ basements and thus stem the volume of radioactive water that it needs to take care of.
The soil freezing had been initially planned to start this month, but preliminary work was suspended for about a month amid safety checks following the death in January of a plant worker in an accident.