OKUMA, Fukushima Prefecture–Almost 700,000 tons of radiation-contaminated water have accumulated at the crippled Fukushima No. 1 nuclear power plant, Tokyo Electric Power Co. disclosed Sept. 4.
The water is stored in rows of massive tanks on the plant’s premises.
Contaminated water has been a persistent problem since the 2011 earthquake and tsunami disaster triggered a triple meltdown at the plant, resulting in a vast amount of radiation being spewed from the facility.
Each day, about 300 tons of groundwater still seeps into the basements of the reactor buildings, where it mixes with melted nuclear fuel and becomes highly contaminated, the utility officials said.
The storage tanks TEPCO has constructed to store the water are 10meters tall and positioned on the inland, and not seaward, side of the reactor buildings.
The plant operator said it had lowered the radiation level of a large portion of the contaminated water using a multinuclide removal apparatus called ALPS (advanced liquid processing system) and other equipment.
The utility completed processing the most highly contaminated water stored in tanks by the end of May.
TEPCO has also worked to replace flange-type bolted storage tanks that are susceptible to leakage with welded tanks to reduce the risk of accidental seepage.
To intercept clean groundwater before it flows into contaminated reactor buildings, TEPCO started a “subdrain plan” Sept. 3 to pump tons of groundwater from “subdrain wells” before it reaches the contaminated reactor buildings each day. The water will be released into the sea after undergoing decontamination treatment
Source: Asahi Shimbun