More than seven years after the March 2011 Fukushima nuclear crisis, radioactive water is continuing to flow into the Pacific Ocean from the crippled No. 1 plant at a rate of around 2 billion becquerels a day, a study has found.
The amount of leaking cesium 137 has decreased from some 30 billion becquerels in 2013, Michio Aoyama, a professor at the Institute of Environmental Radioactivity at Fukushima University, said in his study, which was presented Wednesday at an academic conference in Osaka.
The study said the concentration of radiation — 0.02 becquerel per liter of seawater found in samples collected near a coastal town 8 km south of the No. 1 plant — is at a level that does not affect the local fishing industry.
The radioactive water is generated in a process to cool melted nuclear fuel at three damaged reactors at the complex. The reactors experienced core meltdowns after the March 2011 earthquake and tsunami.
“It can be assumed that there is a path from the complex to the ocean” through which contaminated water flows, Aoyama said.
The water accumulates in the basements of the buildings at the site after being used to cool the melted fuel.
Tokyo Electric Power Company Holdings Inc., the operator of the Fukushima complex, has been trying to prevent contaminated water from increasing within the facilities by building an underground ice wall in an effort to block ground water. It has also built a seawall aimed at preventing contaminated water from entering the ocean.