A decade after the 2011 Great East Japan Earthquake and subsequent tsunami caused a meltdown in the Fukushima Daiichi nuclear plant, the Japanese government decided on Tuesday to approve a plan to release over a million tons of tritium-tainted water into the Pacific Ocean. Neighboring countries, as well as local fishery groups and environmental organizations immediately condemned the decision, while the U.S. government and independent experts were equally quick to endorse the plan.
Though the outcome was inevitable, the government’s decision has long been coming. The contaminated water is accumulating daily at the rate of 140 tons, a consequence of Tokyo Electric Power Co.’s (TEPCO) round-the-clock operation to cool the crippled plant—including the three damaged reactors and the melted nuclear fuel that seeped through their cores and spread to the bottom of their containment vessels. Rain and ground water are also adding to the deluge.
During the cooling process, the water becomes dangerously contaminated and must be filtered using multi-nuclide removal equipment dubbed ALPS (advanced liquid processing system). According to TEPCO, ALPS “removes radionuclides (with the exception of tritium) to levels below ‘concentrations required by law,’ for discharging into the environment. The treated water is then stored in huge steel tanks at the rate of one a week. But with over one thousand tanks already clogging the plant’s site, capacity for further storage is expected to end next year—hence the necessity to release the water.
Because of malfunctions occurring in the early years of the filtering operation, however, “Approximately 70 percent of ALPS treated water presently stored in tanks contains radioactive materials,” such as ruthenium, plutonium, strontium, and cobalt, in concentrations exceeding regulatory standards for discharge.
Consequently, TEPCO will have to construct an additional treatment facility to conduct a second round of filtering of about 750,000 tons of the 1.25 million tons of water currently accumulated.
“By further treating these elements—providing the remaining trace amounts are comparable to or below naturally occurring radiation levels—there is no reason to have health concerns,” says Nigel Marks, a material scientist and associate professor at Curtin University, Perth, Australia. “No separation technology can remove 100 percent of contaminants—even seawater contains traces of uranium.”
Nevertheless, tritium, an isotope of hydrogen that is notoriously difficult to isolate, will remain even after a second round of treatment. So the government’s plan calls for it to be diluted more than 100 times from the regulatory standard of 60,000 becquerels per liter to 1,500 Bq/L—one fortieth of the standard amount. These complications explain why preparations for releasing the water will take two years, and why its discharge will be conducted gradually over decades.
Despite these precautions, there is strong opposition from concerned parties. Greenpeace called the decision “an outrage,” while Japan’s national federation of fisheries cooperatives described it as, “utterly unacceptable,” given the resulting negative publicity is sure to scare off some people from eating fish caught in the area.
Japan’s neighbors were also quick to voice opposition. China’s Foreign Ministry said in a statement, “Despite doubts and opposition from home and abroad, Japan has unilaterally decided to release the Fukushima nuclear wastewater into the sea before exhausting all safe ways of disposal and without fully consulting with neighboring countries and the international community.” South Korea and Taiwan also oppose the plan.
“Such criticisms are driven by politics,” says Marks. “These countries know that Japan has no real option except to pursue ocean dilution. If a similar terrible accident had occurred at one of their nuclear plants, they would almost certainly choose the same path.”
The plan also found support from the U.S. Department of State. It issued a press statement a day before Japan announced its decision, saying, “In this unique and challenging situation, Japan has weighed the options and effects, has been transparent about its decision, and appears to have adopted an approach in accordance with globally accepted nuclear safety standards.”
The International Atomic Energy Agency (IAEA) also backs the plan. IAEA’s director general, Rafael Mariano Grossi, points out the decision will help in decommissioning the nuclear plant, and “is line with practices globally, even though the large amount of water…makes it a unique and complex case.” Grossi added that the IAEA will send experts to review the Japanese plan and monitor the operation.