OKUMA, Japan (AP) — Twelve years after the triple reactor meltdown at the Fukushima Daiichi nuclear power plant, Japan is preparing to dump a huge amount of treated radioactive waste water into the sea.
Japanese officials say the release is inevitable and should begin soon.
Dealing with the wastewater is less of a challenge than the daunting task of decommissioning the plant. This process has barely progressed, and the removal of molten nuclear fuel has not even started.
The Associated Press recently visited the plant. Here’s an update on what’s happening.
HOW TO PREPARE FOR DRAINAGE?
During their visit, AP journalists saw 30 huge tanks used to take samples and analyze the water for security checks. A concrete facility to dilute the water after treatment and testing is in the final stages of construction. From there, the water is drained via an underwater tunnel.
The operator of the plant, Tokyo Electric Power Company Holdings, wants to have the plants ready by spring. TEPCO requires a safety permit from the Nuclear Regulation Authority. The International Atomic Energy Agency, which is working with Japan to ensure the project meets international standards, will send a mission to Japan and prepare a report before initiation begins.
___ WHAT IS TREATED WATER?
A magnitude 9.0 tremor on March 11, 2011 triggered a massive tsunami that destroyed the facility’s power and cooling systems, causing reactors #1, 2, and 3 to melt and emitting large amounts of radiation. Water used to cool the reactor cores seeped into the basements of the reactor buildings and mixed with rainwater and groundwater.
The 130 tons of contaminated water produced daily are collected, treated and then stored in tanks, which now number around 1,000 and cover a large part of the factory site. About 70% of ‘ALPS-treated water’, named after the machines that filtered it, still contains cesium and other radionuclides in excess of releasable limits.
According to TEPCO, radioactivity can be reduced to safe levels and will ensure that under-filtered water is treated until it reaches the legal limit.
Tritium cannot be removed from water, but is harmless in small amounts and is routinely released by every nuclear power plant, officials say. It’s also being diluted, along with other radioactive isotopes, they say. The water release will be gradual and tritium concentrations will not exceed pre-accident levels at the facility, TEPCO says.
___ WHY RELEASE THE WATER?
Fukushima Daiichi has struggled to deal with the contaminated water since the 2011 disaster. The government and TEPCO say the tanks will have to make way for facilities to decommission the plant, such as storage space for melted fuel residues and other heavily contaminated waste. The tanks are 96% full and are expected to reach their capacity of 1.37 million tons in the fall.
They also want to discharge the water in a controlled and treated manner to avoid the risk of leaking contaminated water in the event of another major earthquake or tsunami. It is piped from the sample tanks to a shore basin where it is diluted with seawater and released through an underwater tunnel to a point 1 km (0.6 miles) offshore.
__ WHAT ARE THE SECURITY CONCERNS?
Local fishing communities say their businesses and livelihoods will suffer even more damage. Neighboring countries such as China and South Korea, as well as Pacific island nations, have raised security concerns.
“It would be best if the water didn’t release, but it seems inevitable,” said Katsumasa Okawa, owner of a fish shop in Iwaki south of the facility, whose business is still recovering. Okawa said he hopes further setbacks will be short-lived and that the releases could reassure people to eat fish from Fukushima.
“I find these giant tanks more disturbing,” Okawa said. “The next time the water accidentally spills, Fukushima’s fishing will be over.”
The government has allocated 80 billion yen ($580 million) to support Fukushima fisheries and repair the “reputational damage” caused by the release.
TEPCO has tried to reassure people by keeping hundreds of flounder and abalone in two groups – one in regular seawater and another in diluted treated water. The experiment is designed to “provide people with visual confirmation that the treated water that we consider safe is being released will not have any adverse effects on living beings,” said Tomohiko Mayuzumi, risk communicator at TEPCO.
Radioactivity levels in the flounder and abalone rose while in the treated water, but fell to normal levels within days of being returned to regular seawater. That supports data showing minimal effect of tritium on marine life, said Noboru Ishizawa, a TEPCO official overseeing the experiment.
Officials say the water’s impact on people, the environment and marine life will be minimal and will be monitored before, during and after the releases, which will continue throughout the 30-40 year decommissioning process. Simulations show no increase in radioactivity beyond 3 kilometers (1.8 miles) from shore.
Scientists say the health effects from consuming tritium and other radioisotopes through the food chain could be worse than drinking it in water, and more studies are needed.
Cross-checking is another issue: According to TEPCO, water samples are shared with the IAEA and the government-funded Japan Atomic Energy Agency, but experts would like to see independent cross-checking.
Radiologist Katsumi Shozugawa of the University of Tokyo said his analysis of groundwater at several locations in exclusion zones near the facility showed that tritium and other radioactive elements had leaked into the groundwater.
When highly radioactive water escapes and is dispersed in the sea, it becomes untraceable, worrying not only Japan but also Pacific countries, he said. “There should be an ongoing, science-based effort to show other countries that it’s being thoroughly handled, which I think is most lacking.”
Environmental groups, including Friends of the Earth, oppose the release. They have proposed long-term storage of the water through solidification, such as that used at the Savannah River waste disposal site in the United States
___ ANY ADVANCES ON THE MELTED REACTORS? Huge amounts of deadly radioactive molten nuclear fuel remain in the reactors. Robotic probes have provided some information, but the status of the molten debris is largely unknown.
Akira Ono, who is president of TEPCO’s decommissioning unit overseeing the cleanup, says the work is “unimaginably difficult.”
Earlier this year, a remotely operated underwater vehicle successfully collected a tiny sample from inside the Unit 1 reactor — just a spoonful of about 880 tons of molten fuel debris in the three reactors. That’s 10 times the amount of damaged fuel removed in the cleanup of Three Mile Island after the 1979 partial meltdown.
Test cleanup of the molten debris will begin later this year at Block 2 after a nearly two-year delay. Spent fuel removal from the Unit 1 cooling pool is scheduled to begin in 2027 after a 10-year delay. Once all spent fuel is removed, the focus in 2031 will be on removing molten debris from the reactors.
___ IS A 2051 INTEGRITY TARGET REALISTIC?
Ono says the goal is a good “signpost,” but too little is known. The government is sticking to its original target of 30 to 40 years for the decommissioning to be completed, without defining what that means.
Too ambitious a schedule could result in unnecessary radiation exposure to plant workers and excessive environmental damage, said Ryo Omatsu, an expert on the legal aspects of nuclear power plant decommissioning.
Some experts say it would be impossible to remove all of the melted fuel tailings by 2051.
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