Is the Fukushima Contaminated Water Clean Enough?

One October morning, I scrolled across the usual assortment of news headlines until I hit on the following story: ‘Japan to release treated Fukushima water into the sea.’ Hey, that’s in my backyard, I thought to myself. News reports over the next few days confirmed the Fukushima Daiichi nuclear power plant was exploring the idea of dumping filtered contaminated water into the Pacific Ocean, as of 2022. Born and raised along the southern coast of China, the release of Fukushima Daiichi’s wastewater could have a drastic impact on my family and me if something went wrong. So I began thinking, is dumping treated nuclear wastewater a logical thing to do? What could happen if Japan goes forward with this plan?

The Hypothesis

The null hypothesis in my review of the Fukushima case is that it is ok to release filtered contaminated water from the nuclear plant into the Pacific, and the alternative hypothesis is that releasing the water could be problematic and cause great harm.

If the wastewater would have a negative impact on Earth’s species, and Japan failed the realized that and decided to release contaminated water anyway, the country would commit a Type 2 error because it failed to reject a false null hypothesis that wastewater wouldn’t have a negative impact on human and marine life.

On the other hand, if releasing nuclear wastewater would have no impact on the environment, and Japan decided not to release the water, the country would commit a Type 1 error — failing to reject a true null hypothesis. The financial impact of a Type 1 error would be massive for Japan; the country would waste millions of dollars storing the water needlessly.

What Happened in Fukushima?

Source: USGS

The name ‘Fukushima’ rang a distant bell in my memory — and one associated with danger and tragedy. I did some research to refresh my thinking. In March 2011, a devastating 8.9-magnitude earthquake and a 15-meter tsunami hit Fukushima, causing 200,000 people to evacuate from the area and killing almost 16,000 residents. Worse still, the earthquake and tsunami caused a triple meltdown at the Fukushima Daiichi nuclear power plant leading to the second greatest nuclear disaster in history after Russia’s Chernobyl meltdown of 1986.

Due to the earthquake and tsunami, large amounts of nuclear wastewater from Fukushima Daiichi were accidentally released into the Pacific Ocean. Thankfully, health studies over the past ten years from the United Nations and World Health Organization have found no increases in miscarriages or birth defects which can be aftereffects of nuclear plant disasters.

I knew water was used as a coolant in nuclear power plants. However, I wasn’t clear on the amount of water required for cooling purposes or the typical approach to storing toxic water, so I studied up. Water that is used to cool reactor areas gets contaminated when it comes into contact with damaged reactors and fuel debris. The Fukushima Daiichi plant now has more than 1.2 million tons of water stored in over 1,000 tanks, and they are building new ones daily. The total amount of contaminated water is expected to rise to 1.37 million cubic meters by the end of 2020 and the storage will reach its full capacity in summer 2022. With these facts and figures in mind, I started to understand why the Japanese government was considering the hopefully safe release of filtered contaminated water from Fukushima Daiichi into the Pacific.

Surely, there must be other methods to dispose contaminated water safely!

Releasing filtered nuclear plant water into the Pacific seems like an extreme measure to me. Certainly, Japan must be considering other options, I thought to myself. China, South Korea, and the Philippines wouldn’t abide by a one million cubic ton dump of nuclear plant water.

Yes, indeed, Japan has dumping options. But which option will they choose, weighing all of the costs and risks? In 2013–2016, Japan’s Tritiated Water Task Force conducted technical evaluations of alternate disposal methods. It considered 5 options: 1) geosphere injection, 2) offshore release, 3) vapor release,4) hydrogen release, and 5) underground burial. Technical feasibility (including monitoring to ensure safety), regulatory feasibility period and costs were examined, and all cases were examined on the premise that there would be no scientific impact on humans when disposing filtered contaminated water. The Task Force concluded that direct disposal is the cheapest and the quickest of the 5 methods, costing 3.4 billion yen (US$30 million) with slow release of the filtered contaminated water into the Pacific over a period of 7.5 years (METI, “Tritiated Water Task Force Report”, June 2016 Tritiated Water Task Force” June 2016).

Offshore Disposal, How It Should be Done?

OK, I can imagine neither of the five options profiled above is great for the environment. If offshore release is the cheapest and quickest option, studies show it could also be safe. Let’s hope that’s the case. Assuming Japan proceeds with its offshore release plans, what plan would they follow? The government and the plant operator, Tokyo Electric Power Co., (TEPCO) would use ALPS (Advanced Liquid Processing System) and other equipment to treat the contaminated water which is stored in the tanks. This system is designed to eliminate radioactive elements such as strontium-90 and cobalt-60.

Fukushima Daiichi nuclear power plant

source: Japan Ministry of Economy, Trade and Industry

Early research studies by TEPCO show the ALPS process is a safe way of filtering contaminants from nuclear wastewater. A 2015 International Atomic Energy Agency (IAEA) report stated, “Initial results from tests using contaminated sea water and outlet water from the cesium removal process have demonstrated that 62 radionuclides can be removed to achieve levels that satisfy the regulatory limits for discharge.” (Opcit. Nuclear Emergency Response Headquarters, 3 September 2013.) But in March 2015, TEPCO disclosed that the system had failed to reduce the levels of radioactivity to below the limit for ocean discharge and was not performing optimally. (TEPCO, “Regarding contaminated water purification” March 16 2015, Tokyo Electric Power Company) Emotionally, however, I still don’t like the idea of dumping one million cubic tons of this water into ocean water flowing China’s way.

But a deeper analysis of the contaminated water reveals there’s a catch. Currently, 72% of Fukushima Daiichi’s one million metric tons of water contain additional radioactive materials exceeding allowed limits for ocean dumping and requiring the plant’s contaminated water to be processed again. According to TEPCO, the level of strontium-90 is more than 100 times the authorized safety level. In some tanks, the level of highly toxic strontium-90 is 2,000 times the authorized standard. Strontium-90 can cause bone cancer of nearby tissues, and leukemia.

TEPCO claims its water treatment systems can ensure Fukushima Daiichi’s treated water meets global safety standards required for the water to be released into the Pacific following a second round of treatment. However, my research indicates there are suspicions about the transparency and accuracy of the information TEPCO is providing. As I continued my research, my concerns about the danger of releasing Fukushima Daiichi’s filtered contaminated water into the ocean near my home kept growing!

What contaminants remain in the filtered water even it achieves minimum standards for safety?

First, Carbon-14, which is a radioactive isotope with a half-life of 5,730 years. If released into the ocean, a report by Greenpeace, a non-governmental environmental organization, state carbon-14 has the potential to damage human DNA in ways we are only beginning to understand.

Second, Tritium or hydrogen-3, a rare and radioactive isotope of hydrogen which exists naturally and has a low impact on human and marine health. Happily, Tritium has a short half-life of 12.3 years. Delaying the start of release of Fukushima Daiichi’s water into the Pacific could allow the potential harm of tritium to diminish completely.

Ocean currents flowing toward South Korea and China

The impact of discharging Fukushima Daiichi’s still radioactive water into the Pacific would affect not only Japan, but neighboring countries South Korea and China, too. And any potentially dangerous toxins could be carried a lot further across the seas. Tritium is light, so water with this contaminant could reach as far as the US west coast within two years, says Ken Buesseler, a senior scientist at Woods Hole Oceanographic Institution. Fukushima Daiichi’s filtered contaminated water could indeed threaten the safety of the waters and environment throughout the Asia Pacific, the west coast of North America, and potentially farther.

source: Ken Buesseler, Science, 07 Aug 2020

In my research, I note the key issue is transparency. As a Chinese citizen and resident, I’m not convinced the Japanese Government and TEPCO have been transparent with their information on plans to process Fukushima Daiichi’s water for release into the Pacific. Even after reviewing reports from the Japanese authorities, environmental groups and scientists remain concerned that additional, dangerous radionuclides, such as strontium-90, cobalt-60, iodine-129, have not been transparently reported by Japanese authorities but would remain in the water released to the Pacific. While ALPS has reduced the concentrations of these radionuclides through its treatment processes, remember that 72% of the water would need to flow through a second round of treatment. Regarding Japan’s 2022 plan for releasing filtered contaminated water, “There are major questions as to whether it will work as planned,” says Shaun Burnie of Greenpeace. If those chemicals are not removed before disposal, they would harm the marine life and the fish eventually consumed by humans.

“Japan needs to prove that they have efficiently filtered the water, slowly released it into the sea, and actively monitored the damage its causing”, says Buesseler.

This would be a tall order.


Soon after I read about Fukushima Daiichi’s plans to dump its filtered water, protests erupted in Japan and elsewhere, and Japanese officials decided to postpone the plan of releasing radioactive water off the eastern coast of Japan. So, the issue remains: What will Japan do with its one million cubic tons of nuclear wastewater sitting in tanks which will fill to capacity by 2022? It is not easy to make a decision on what to do with the contaminated water in Fukushima. Releasing the water into the Pacific Ocean remains a potential route if scientists can ensure that no dangerous isotopes remain in the treated water, and if the Japan authorities can prove transparency in sharing their plan with its citizens and the world. I remain skeptical that ocean dumping is the best path. The long-term environmental impact from contaminated water is unknown and could cause higher risks than expected. How would filtered contaminated water affect human and marine life? If Japan makes a Type 2 error by falsely releasing still dangerous radioactive water into the Pacific, the price to pay would be catastrophic for current and future generations. As a concerned citizen and resident of China, I hope Japan shows the world its comprehensive safety data before releasing any filtered contaminated water into the ocean.

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