Groundwater is seeping into the damaged reactor buildings at the crippled Fukushima No. 1 nuclear plant, and Tokyo Electric Power Co. plans to build about a dozen wells to redirect and halve the flow.
Groundwater from precipitation is mixing with highly radioactive cooling water gathering in the reactor buildings, turbine buildings and basements, increasing the volume of tainted water at the complex.
The utility thus wants to use the wells to direct some of the groundwater into the Pacific Ocean — likely about 1,000 tons per day — before all of it seeps into the reactor buildings and elsewhere.
Tepco says it will check the contamination level of any groundwater before releasing it into the sea.
“By creating a groundwater bypass, the amount of water flowing (into the) reactor buildings is expected to be reduced by about 50 percent,” Tepco said in a paper it submitted to the government at a meeting to check its progress on decommissioning the four crippled reactors.
A government official who briefed reporters on the meeting said the bypass is likely to become operational around September or October.
The Fukushima plant generates large volumes of highly radioactive water on a daily basis because it must perpetually cool melted fuel in reactors that are riddled with meltdown holes, as well as the spent-fuel pools sitting on top of them. Since the vessels are leaking, the water keeps the reactor buildings, turbine buildings and their basements flooded.
Some of this coolant water is recycled by reducing its radioactivity through a jury-rigged water-purifying facility set up once the crisis stabilized. But the tanks used to store the processed water could soon become full if they have to store groundwater as well.
Meanwhile, the chief of a government-appointed panel probing the Fukushima disaster said Monday it has questioned Naoto Kan, who was prime minister when the triple calamity hit.
Yotaro Hatamura said it is “not appropriate” to elaborate on what was said at the hearing, but added he felt the nation’s scrappy and determined former leader spoke “frankly about his thoughts at that time.”