Japan Must Be Transparent on Fukushima Water Discharge
Echo Xie / South China Morning News
(April 18, 2021) — Japan should increase the transparency of its controversial plan to carry out a second round of treatment of contaminated water from the Fukushima nuclear power plant
to reassure neighboring countries and other stakeholders, experts said.
About 1.25 million tons of contaminated water are held in about 1,000 tanks at the Fukushima Daiichi site. The Japanese government decided on Tuesday it would release it into the Pacific Ocean in two years, and on Friday said it would draw up an action plan for the discharge.
It said it would also organize working group sessions to hear the opinions of local governments and fisheries organizations, and conduct a survey of local residents starting from next month.
“In the coming years, Japan needs to publish monitoring data so we can see the treatment ability in the first and second processes. This is a key question,” said Ray Lei Yuting, head of research unit at Greenpeace East Asia, adding that Greenpeace strongly opposed the discharge of the water.
Lei Yian, an associate professor in physics at Peking University, said third-party institutions should monitor the process.
“[Japan] said the concentrations of radionuclides were very low after the first treatment but later it was found out that some nuclides still had high concentrations,” he said.
“So it needs to have a third-party institution to monitor the level of radionuclides after the second treatment.”
Tokyo’s decision has already triggered outcries not only from Japanese fishermen but also neighboring countries, including China and South Korea.
China’s foreign ministry on Thursday “lodged solemn representations” with Japanese ambassador to China Hideo Tarumi and accused Tokyo of a “suspected violation of international law”. South Korea is reported to be considering filing a petition against Tokyo’s decision at the International Tribunal for the Law of the Sea, including calling for an injunction.
But Japan has received backing from the United States, which said Tokyo “appears to have adopted an approach in accordance with globally accepted nuclear safety standards”. The IAEA, the atomic watchdog of the United Nations, said it welcomed Tokyo’s decision and it would “work closely with Japan before, during and after the discharge of the water”.
Chinese experts said it was natural for Beijing to object to Tokyo’s decision and that the protest was not influenced by the recent poor relations between the two countries.
“There’s no direct relation between China’s stance on the Fukushima waste water issue and the pressure it faces from Japan and the US,” said Liu Jiangyong, a professor of international relations at Tsinghua University.
“Pressure or not, any responsible government would raise concern if [the waste water] affects the environment and people’s health in the neighboring countries,” he said.
One of the reasons for the opposition is that Japan’s plan will not solve the problem at Fukushima, according to experts.
In 2011, a magnitude 9 earthquake and subsequent tsunami crippled the Fukushima nuclear power plant’s cooling system and caused a meltdown of three nuclear reactors. Molten fuel debris burned through the pressure vessel and then into the concrete base of the containment vessel. Since then, the plant’s operator, Tokyo Electric Power Company (Tepco), has been pumping cold water into each reactor to cool the molten fuel.
Mycle Schneider, a Paris-based nuclear energy consultant, said that because the containment vessels were no longer watertight, some of the water had drained into the basement and mixed with the groundwater.
“What they are doing is they are taking out an equivalent amount of water which they pumped into the reactors … but because of the influx of groundwater, you are permanently mixing up freshwater with this highly contaminated water,” he said.
“It means you have another thousand cubic-meter tank that will fill up in five to six days. It’s not a solution,” he said. “This might go on for years and years and years if they don’t solve the issue of influx of water in the first place.”
The 1.25 million tons of contaminated water is held in almost 1,000 tanks but Tepco said they would be full by the second half of next year.
The Japanese government assessed five options to deal with the problem – including evaporating it into the atmosphere, injecting it into deep geosphere layers and burying it underground – but discharging it into the ocean was deemed the cheapest and fastest solution.
Japanese Prime Minister Yoshihide Suga said on Tuesday that “the treated water’s discharge is an unavoidable issue in the process of decommissioning the Fukushima No. 1 nuclear power plant”.
The contaminated water would run through a filtration system, which captures dozens of radioactive substances except for tritium, a radioactive isotope of hydrogen with a 12.3-year half-life.
Tritium can exist within the human body. Due to its chemical properties, it is considered one of the least harmful radionuclides. It is considered to be hazardous to health only in large amounts, according to the Health Physics Society.
The water in the tank contains about 860 trillion becquerels of tritium, while an estimated 1.2 quadrillion becquerels remain inside the reactor building and the reactor itself, according to Tepco.
The company said in 2018 that as well as tritium, more dangerous isotopes with longer radioactive lifetimes were contained in the treated water, including carbon-14, cobalt-60 and strontium-90.
“These and the other isotopes that remain all take much longer to decay and have much greater affinities for sea floor sediments and marine organisms like fish, which means they could be potentially hazardous to humans and the environment for much longer and in more complex ways than tritium,” Ken Buesseler, a marine chemist at the Woods Hole Oceanographic Institution, said in a paper published last year.
Schneider said: “The question is how we guarantee that when they call ‘decontaminated’ is effectively decontaminated to a level that is acceptable not only locally but internationally because this goes into the ocean, a global good.”
Lei Yuting said: “The questions are if Tepco can treat the water, how much they can treat and how much time it takes.”
However, Lei Yian, said the contaminated water would be diluted by seawater and the environmental impact would be limited.
“The radiation of those radionuclides is about 100 times the background radiation, so if the sea dilutes the waste water by 100 times, it would be similar to the radiation level in the present environment,” he said.
Lei Yuting said: “The multiple radionuclides that the Japanese government decides to discharge into the ocean are complex in varieties and properties with longer half-life and they may cause danger to the DNA of human beings and other organisms.”
“What we have to deal with is the aftermath of the unprecedented nuclear disaster, and we must seek the most appropriate solution from a forward-looking and cautious perspective,” he said.
Additional reporting by Josephine Ma
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