The hazards of Japan's discharge of nuclear contaminated water

On the morning of August 24, local time, Tokyo Electric Power Company held an impromptu press conference. Tepco announced that the discharge of contaminated water from the Fukushima Daiichi nuclear power plant will start at 1 p.m. local time today.

Today’s discharge of contaminated water is expected to be 200 to 210 tons, and the daily discharge will be announced the following day. The first discharge will discharge about 460 tons per day for 17 days, totaling about 7,800 cubic meters of nuclear-contaminated water. According to Tepco’s calculations, the contaminated water diluted with seawater will slowly flow through about 1 kilometer of tunnels and reach the sea in about 1,000 seconds.

Fukushima Daiichi nuclear power plant nuclear contaminated water storage facility

1.What’s in Japan’s nuclear-contaminated water?

Radioactive nuclides such as tritium, strontium-90, cesium-137, cobalt-60 and carbon-14 were found in the contaminated water in Japan.

Tritium

A very small amount of tritium has little effect on the human body, but the oxide of tritium can be absorbed by lung tissue and undamaged skin to the greatest extent, resulting in internal irradiation, which will cause serious damage to genetics, reproduction and growth and development.

Cesium

Cesium-137 has strong radioactivity, volatility and activity, and cesium-137 in the environment is easy to stay in the body’s soft tissues after entering the human body, especially in muscles, and excessive intake will increase the risk of cancer.

Iodine

131 iodine in radioactive iodine pollution is a highly toxic nuclide, which is easy to accumulate in the thyroid after entering the human body and damage thyroid cells. When the damage continues, the human body will suffer from hypothyroinemia, which may even lead to cancer. In addition, due to the vigorous thyroid metabolism of minors, the damage is relatively serious.

Strontium

Strontium is highly toxic, and when a large dose of radioactive strontium enters the body, it will cause acute or chronic damage to the body, because the chemical properties of strontium and calcium are similar, as a typical osteophilitic element, it is easy to affect the calcification process of bones and teeth, resulting in distortion, cancer, etc., which endangers bone health.

Japan claims that the water discharged by Japan is not “nuclear contaminated water”, but treated water purified by ALPS “multi-nuclide removal equipment”. However, according to the US magazine Science, ALPS sometimes miss longer-lived and more dangerous isotopes such as ruthenium, cobalt, strontium and plutonium during the purification process. The half-life is tens of thousands of years.

The radioactive tritium in the nuclear-contaminated water will be absorbed by seaweed, forming stable organic tritium, which will be eaten by fish and shrimp and go to the human table. In addition, the half-life of cobalt-60 in nuclear contaminated water is about 5.27 years, and it will release gamma rays in the process of decay, and if people are exposed to gamma rays for a long time, it will cause diseases of the blood system. Radioactive elements in nuclear contaminated water have a short half-life of more than ten years, and the longest can reach more than 5,000 years.

2.Why does Japan insist on polluting despite opposition?

After the 2011 Fukushima disaster in Japan, the Tokyo Electric Power Company injected massive amounts of cooling water into the reactors to control their temperature. As cooling water from the reactors and rain and groundwater pour in day after day, more and more radioactive water is being produced inside the plant.

In fact, the treatment of nuclear contaminated water is not the only option. In the report issued by the Japanese government expert group, five options have been proposed, including injection into the formation, discharge into the ocean, steam discharge, electrolytic release, and solidification landfill.

Of the five options, discharging contaminated water into the sea is the least costly, with an estimated cost of 1.7 billion to 3.4 billion yen, or about 102 million to 203 million yuan. The most expensive way is to freeze it and bury it underground, which is estimated to cost tens or even hundreds of times as much as discharging it into the sea.

In February 2020, the relevant committee of the Japanese government responsible for dealing with the problem of nuclear contaminated water issued an assessment report, listing two options for discharging into the sea and releasing steam, and saying that combining operational, technical, economic and time factors, discharging into the sea is “more practical”. Japan said that the tritium discharge into the sea has a “relatively small” impact on human health.

Experts believe that the international community has so far been unprecedented in the release of nuclear-contaminated water into the ocean. According to the United Nations Convention on the Law of the Sea, this act of the Japanese government will constitute a typical act of Marine environmental pollution and should bear the corresponding responsibility under international law.

In the end, however, Japan chose the “shortest time and least cost” option of discharging into the sea, intending to pass on the risk to the world.

Fukushima Daiichi nuclear power plant

3.Is imported seafood still edible?

Since the Fukushima nuclear accident in 2011, China has introduced relatively strict testing standards for imported food from Japan. The import of food and feed from some parts of Japan shall provide the certificate of qualified radioactive substances and the certificate of origin issued by the Japanese government; Local inspection and quarantine agencies shall test imported food for radioactive substances and import it only after passing the test. Since 2012, the monitoring of radioactive substances in food has been included in the scope of national food safety risk monitoring. Therefore, we should both be vigilant, but also do not have to worry too much, we buy seafood through regular channels, basically meet the national testing standards, you can rest assured to eat.

The nuclear contaminated water has little impact on China’s offshore fisheries, because according to the North Pacific Ocean current chart, the nuclear contaminated water will drift northwest with the Japan Warm Current, and will first reach the waters of Canada with the North Atlantic Warm Current, then spread to the waters of the West coast of the United States under the push of the California Current, and finally reach the waters of Taiwan, China, and further spread to the waters of the East China Sea through the North Equatorial Warm Current. This process takes a long time, and water from inland rivers is injected offshore, further reducing the impact.

However, for the pelagic fisheries, the impact of nuclear contaminated water is relatively large, and China’s pelagic fisheries are mainly concentrated in the Pacific Rim waters, among which the northwest Pacific waters are also the first sea areas affected by the pollution diffusion after the discharge of nuclear contaminated water.

Therefore, when choosing and eating seafood, we should pay attention to its origin and type, and make judgments according to relevant labels and information.

4. Did Japan’s actions violate international law?

Opposition is mounting in Japan as the government moves ahead with plans to release nuclear-contaminated water from the Fukushima Daiichi nuclear power plant into the sea. Japanese lawyers say the discharge of nuclear-contaminated water into the ocean is a breach of international law.

Etsuro Tozuka, a Japanese lawyer who has litigated pollution-related cases for decades, pointed out that Japan is a party to international conventions such as the United Nations Convention on the Law of the Sea and is obliged to abide by them, and that pushing ahead with the plan violates its obligations under the convention.

Etsuro Tozuka, Japanese lawyer: Article 192 of the United Nations Convention on the Law of the Sea stipulates that all States parties have the obligation to protect and preserve the Marine environment. Article 194, paragraph 3, stipulates that the discharge of toxic and harmful substances from land and the discharge of nuclear-contaminated water containing radioactive substances into the sea shall be prevented in violation of the provisions of these articles.