Out of sight, out of mind

Plans for the disposal of radioactive cooling water in Fukushima

In late January, a Japanese government task force recommended that 1.2 million tons of radioactive water be discharged into the Pacific Ocean. Since the triple meltdown at Fukushima 10 years ago, the damaged reactors have had to be continuously cooled from the outside.

However, because the reactors are destroyed and the highly radioactive fissile materials uranium and plutonium are relatively unprotected at the bottom of the reactor core, the cooling water becomes heavily contaminated with radioactivity. Only part of this contaminated cooling water can be pumped out of the reactor carcasses afterwards (about 400 tons per day), the rest seeps directly into the groundwater and the nearby sea.

The collected water is pumped into large tanks on the site of the power plant. More than 1,000 of these tanks have already been built and more are being added all the time.

Now TEPCO is arguing that there is not enough space for additional tanks and is increasing pressure on the Japanese government to allow the contaminated water to be dumped into the ocean.

The plan is to gradually release the water into the sea, where it will be diluted in a "natural way" - a horror scenario for local residents, fisheries and agriculture in the region, all of whom fear that food safety concerns could reignite if radioactive strontium, tritium and other radioisotopes were released into the sea in larger quantities. With a petition, they collected more than 250,000 signatures in a short period of time against the release of the liquid radiation waste into the sea.

The Japanese Ministry of Economy, Trade and Industry (METI) and the International Atomic Energy Agency (IAEA), on the other hand, have already given the plan green light - they consider the release of the contaminated water into the ocean to be acceptable and possible health risks to be "low." They argue that the water contains only the "relatively harmless" radioisotope tritium and that all other radioisotopes are filtered out.

But who is right? To answer this question, it is worth taking a look at the assurances made so far by the operating company TEPCO regarding the treatment of the radioactive water and the reality on site.

The same government task force that is now recommending dumping the radioactive water into the sea had already advised the government on how to process the water at the beginning of the nuclear disaster. At that time, they had recommended the relatively inexpensive "Advanced Liquid Processing System" (ALPS), which would remove all radioactive materials from the water until they were no longer detectable - except for tritium, which cannot be removed with this technology. Critics noted that ALPS could not accomplish this and suggested more elaborate technical solutions, which were rejected. The ALPS was installed and the pumped-off water was treated with it. Officially, this went completely according to plan for many years, with supposedly excellent results.

Independent investigations of the water tanks were repeatedly rejected by TEPCO. Today, we know why. In September 2018, after leaked documents came to light, TEPCO had to admit that the ALPS process did not meet expectations and that more than 62 radionuclides could still be found in the water that had already been treated, including radioactive strontium, which causes leukemia, radioactive cesium, which can lead to solid tumors in the body, radioactive iodine, which affects the thyroid gland, and radioactive cobalt, which can lead to acute radiation sickness. All of these substances, if released into the sea, could find themselves in the animal and plant life of the ocean floor, accumulate in fish, seafood and algae, and soon find their way onto consumers' plates through the marine food chains.

TEPCO issued an official statement apologizing for years of misinformation and admitting that more than 80% of the stored water continued to exceed government-defined limits for radioactivity.TEPCO spokesman Kenji Abe said at the time that there were "other substances in the tanks besides tritium. They have not been filtered out yet." In other words, of the 890,000 tons of irradiated water at the time, 780,000 tons were contaminated with dangerous radioisotopes even after treatment with ALPS. In 65,000 tons of water, radiation doses were even more than 100 times higher than government limits allowed. Radioactive strontium-90, for example, was measured in some containers at 600,000 Bq/l - about 20,000 times higher than the official limit.

Time constraints were cited as the reason for the failure of the ALPS technique: "We were in a hurry at the time," Abe said. However, Kazue Suzuki of Greenpeace Japan sees mainly economic reasons behind TEPCO's failure on the water treatment issue: "The decision not to develop water treatment technology that could remove radioactive tritium was motivated by short-term cost-cutting, not by protecting the environment of the Pacific Ocean or the health and livelihoods of communities along the Fukushima coast." In addition to the choice of the relatively low-cost ALPS technology, he said, bad decisions were made repeatedly throughout the process. Among other things, he said, reagents were not replaced at the proper intervals, presumably to save money.

TEPCO has promised since the scandalous admission in September 2018 to approach water treatment with greater care, but continues to stick to the controversial ALPS technology and claims that it will enable the company to eventually release the contaminated water into the sea. Based on these promises, the same working group that recommended the introduction of ALPS at the time now recommends the early disposal of the "treated water" into the ocean.

So has TEPCO done its homework? Independent measurements are still not allowed, so one has to rely solely on the company's own figures for evaluation. But these are damning enough: a query of the official water test values in December 31, 2019 continues to show a worrying picture: of a total of 1,080,700 cubic meters of water, just 28% (300,000 cubic meters) meet the legal limits. The rest are well above these limits, as this graph from TEPCO's own website illustrates:

TEPCO insists that further purification steps with ALPS could reduce radionuclides to levels below the legally prescribed limits. Whether this will be possible with ALPS can at least be doubted on the basis of current experience with TEPCO's track record. Independent scientists continue to regard the dumping of radioactive water in the tanks as an irresponsible ecological and health risk and emphasize that even the supposedly "harmless" tritium is a beta emitter and thus hazardous to health if inhaled, absorbed with food, drinking water or through the skin. The biological half-life of tritium in the human body is between 7 and 14 days. This means it takes 1-2 weeks to excrete half of the ingested tritium. In the body, tritium can cause DNA damage, leading to mutations and cancer. Tritium cannot be distinguished from regular water by the body and therefore travels wherever there is water, which means practically every tissue and part of the body. Especially during pregnancy, there is a risk that tritium can damage unborn life in the womb via the umbilical cord and amniotic fluid and lead to cancer later in life.

Instead of dumping the contaminated water into the ocean, further storage on land, preferably earthquake-proof, for a period of about 100 years would be conceivable, since many of the radioactive isotopes would became less hazardous during this time simply through their natural decay, and completely different technical processes would then be possible to decontaminate the water. The argument that there is not enough space on the power plant site for more tanks is not very convincing anyway, since the entire surrounding area is a huge exclusion zone. Regardless of what technical solutions are chosen, dumping the contaminated water into the sea is certainly a risk that should be avoided at all costs.

 

Dr. med. Alex Rosen
Pediatrician and Co-Chair of the German Section of IPPNW



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