OKUMA, Japan — Twelve years after the triple reactor meltdowns at the Fukushima Daiichi nuclear power plant, Japan is preparing to release a massive amount of treated radioactive wastewater into the sea.
Japanese officials say the release is unavoidable and should start soon.
Dealing with the wastewater is less of a challenge than the daunting task of decommissioning the plant. That process has barely progressed, and the removal of melted nuclear fuel hasn’t even started.
HOW ARE WATER-DISCHARGE PREPARATIONS PROCEEDING? During a recent visit, Associated Press journalists saw 30 giant tanks for sampling and analyzing the water for safety checks. A concrete facility for diluting the water after it is treated and tested is in the final stages of construction. From there, the water will be released via an undersea tunnel.
The plant’s operator, the Tokyo Electric Power Co., aims to have the facilities ready by spring. TEPCO needs a safety approval from the Nuclear Regulation Authority. The International Atomic Energy Agency, collaborating with Japan to ensure that the project meets international standards, will send a mission to Japan and issue a report before the discharge begins.
WHAT IS TREATED WATER? A magnitude-9.0 quake on March 11, 2011, triggered a massive tsunami that destroyed the plant’s power supply and cooling systems, causing three reactors to melt and spew large amounts of radiation. Water used to cool the reactors’ cores leaked into the basements of the reactor buildings and mixed with rainwater and groundwater.
The 130 tons of contaminated water created daily is collected, treated and then stored in tanks, which now number about 1,000 and cover much of the plant’s grounds. About 70 percent of the treated water still contains cesium and other radionuclides that exceed releasable limits.
TEPCO says the radioactivity can be reduced to safe levels and it will ensure that water is treated until it meets the legal limit.
Tritium cannot be removed from the water but is unharmful in small amounts and is routinely released by any nuclear plant, officials say. It will be also diluted, along with other radioactive isotopes, they say. The water release will be gradual and tritium concentrations will not exceed the plant’s pre-accident levels, TEPCO says.
WHY RELEASE THE WATER? Fukushima Daiichi has struggled to handle the contaminated water since the 2011 disaster. The government and TEPCO say the tanks must make way for facilities to decommission the plant, such as storage space for melted fuel debris and other highly contaminated waste. The tanks are 96 percent full and expected to reach their capacity of 1.37 million tons in the fall.
They also want to release the water in a controlled way to avoid the risk that contaminated water would leak in case of another major quake or tsunami. It will be sent through a pipe from the sampling tanks to a coastal pool to be diluted with seawater and released through an undersea tunnel to a point 1 kilometer offshore.
WHAT ARE THE SAFETY CONCERNS? Local fishing communities say their businesses and livelihoods will suffer still more damage. Neighboring countries such as China and South Korea and Pacific Island nations have raised safety concerns.
“It would be best if the water isn’t released, but it seems unavoidable,” said Katsumasa Okawa, owner of a seafood store in Iwaki, south of the plant.