Japan's large-scale discharge of nuclear-contaminated water has caused controversy, experts: the most "economical", but harmful to others and harming themselves

Core Takeaways:

• 1 There is not enough research data on how much tritium can cause harm to the human body. In addition, cesium-90, cesium-137 and other nuclides that are easier to bind to biomass that do not appear in the conventional wastewater of ordinary nuclear power plants are also the focus of our attention.
• 2 Although the ocean has a strong dilution self-purification ability, due to the long half-life of radionuclides, even if the radionuclide concentration in the ocean is very low, it may accumulate through the food chain enrichment and affect the consumption of seafood.
• 3 Unlike food safety reviews, which have clear standards, many risks of skin care products and cosmetics are unknown, and there is a lack of relevant laws and regulations to review raw materials and origins, and we need to be vigilant about them.
• 4 Draining contaminated water into the sea is not the only option for Japan, and there are many other alternatives, including viable options such as formation injection, steam emissions, hydrogen emissions, and underground burials. Japan abandoned other, more reliable options and chose to discharge directly into the sea because it was "the most economical" and "most convenient".
• 5 By resorting to the International Court of Justice and the International Tribunal for the Law of the Sea, the long-term significance of achieving conviction and accountability for Japan's nuclear contaminated water discharge plan is far greater than the practical significance, which will help all parties clearly understand their environmental protection obligations and reach a broader consensus on marine environmental protection.

TEPCO's Fukushima Daiichi Nuclear Power Plant is about to be discharged into the sea, causing global concern. Since this was the first large-scale discharge of nuclear-contaminated water in human history, it was widely controversial.

On July 3, Japan's Chief Cabinet Secretary said that the time for discharging contaminated water from TEPCO's Fukushima Daiichi nuclear power plant into the sea would be around summer, a policy that has not changed.

On July 4, the International Atomic Energy Agency said Japan's plan to discharge contaminated water into the sea meets international safety standards.

Does nuclear-contaminated water directly affect the growth of marine life such as fish? Can the affected seafood be consumed by us? Is direct discharge of nuclear effluent the only option for the Japanese government? Do mainland coastal areas need to strengthen nuclear radiation detection for catering?

In this issue of Tencent News "Let's Talk Together", Ren Hui (general history author) talks with Dalian Zhang Yanyi (Dean of the Huang Bohai Research Institute of Dalian Maritime University and Professor of the Law School) and Zhang Zili (popular science author in the field of electrical engineering) to discuss the crisis, dilemma and breakthrough of Japan's nuclear contaminated water into the sea.

1. What exactly is the discharge of Fukushima's nuclear contaminated water into the sea?

Ren Hui: TEPCO's Fukushima Daiichi Nuclear Power Plant is about to discharge contaminated water into the sea, which has attracted global attention. Since this was the first large-scale discharge of nuclear-contaminated water in human history, it was widely controversial. The Japanese side said that a small amount of tritium in the nuclear-contaminated water does not affect human health, whether the contaminated water containing tritium nuclear pollution will not endanger human health, and what is tritium?

Zhang Zili: Tritium is a superweight isotope of hydrogen, and water containing tritium is commonly known as superheavy water. General radioactive substances exist in the form of dissolved substances, suspensions, metal ions, etc. in the solvents of water. But the difference is that tritium is "water" itself, so tritium is extremely difficult to separate from nuclear-contaminated water.

As a radioactive substance, tritium is necessarily harmful. According to the International Commission on Radiological Protection, there is no safe ionizing radiation threshold for any radioactive material, that is, there is no safety limit, the lower the better, preferably zero, tritium without exception exposure to a large amount of tritium will inevitably damage the human body.

Tritium may not produce the same nuclear pollution bioconcentration effect as cesium, strontium and other metal radioactive elements (editor's note: biological enrichment effect refers to some toxic substances in the environment, such as heavy metals, chemical pesticides through the food chain in the organism accumulation in large quantities, damage to health process), and tritium in the form of water into the body, is likely to be excreted with sweat or urine after the body's circulation.

However, there is not enough relevant research data on how much tritium harms the human body and how much residue it has.

Ren Hui: Some media said that the Japanese government and TEPCO used tritium to divert attention and cover up other harmful radioactive materials in the nuclear-contaminated water. What other nuclides in nuclear-contaminated water pose a threat to ecological security?

Zhang Zili: The core composition, initial raw materials, power density and operating time are different, and the composition of radioactive materials in the reactor is also different and difficult to measure. Cesium-137, cesium-134 and strontium-90 are the three most common and most damaging heavy metal radioactive elements to the human body. However, there are many possibilities for radioactive elements discharged from Fukushima's contaminated water, such as transuranic elements, ruthenium, rhodium and other extremely rare elements, and their situation is complex and difficult to judge.

The degree of harm to the human body and the half-life of radioactive elements (Editor's note: the time it takes for radionuclides to decay in half)

Relate. Nuclides with a half-life of up to millions of years, extremely low radioactive activity, and little harm to the human body; Nuclides with a half-life of only a few days, high radioactivity, good isolation and protection can effectively reduce the hazard. But nuclides with half-lives of several decades are the most harmful to the human body and are the primary indicator for us to measure radioactive elements.

The main migration and diffusion paths of artificial radionuclides after nuclear accidents (Source: Research Progress on Enrichment, Distribution and Radiation Damage of Artificial Radionuclides in Marine Fish)

Ren Hui: You have just mentioned the biological enrichment of nuclear pollution, how high will radioactive elements be enriched in the biological chain with the continuous discharge of nuclear contaminated water?

Zhang Zili: The mechanism of this problem is quite complicated. Assuming that Japan's nuclear contaminated water discharge does meet the reported standards, then the naturally enriched content of heavy metal elements is acceptable. However, whether the results of Japan's nuclear contaminated water treatment meet the standards and whether the discharged nuclear contaminated water has really been standardized needs to be verified.

According to media reports, fish caught off the coast of Fukushima detected 180 times more uranium-137, caused by the explosion of the Fukushima nuclear power plant in 2011. After more than ten years, the enrichment effect of radioactive elements in fish is very significant.

Standards for radioactive materials vary around the world. The so-called "detection 180 times more than the standard" is actually "18 times more than the standard" compared to the international standard, but this dose is also quite dangerous, and it will produce a similar enrichment effect in other marine organisms such as shrimp and crabs.

We need to note that many of the more than 60 radionuclides in Japan's nuclear-contaminated water do not yet have effective treatment techniques. For example, most heavy metal elements such as strontium-90 are not easy to be excreted, and a large amount of residue will lead to an enrichment effect.

Although the content of tritium in nuclear-contaminated water is the highest and the ability to spread in the ocean is very strong, the ability to combine with biomass and enrich in the food chain is weak. There are no caesium-90 and cesium-137 nuclides that are easier to combine with biomass in the conventional wastewater of ordinary nuclear power plants, and they should be the focus of our attention.

Ren Hui: As Zhang Zili said, different radionuclides have different effects on organisms, tritium in Fukushima nuclear wastewater, although it has the strongest transmission and diffusion ability, but the ability to enrich in organisms is the lowest, while radionuclides such as carbon 14 can reach 9,000 times that of tritium in organisms, radioactive iodine can be enriched in seaweed and thyroid, the dose conversion factor is 4 orders of magnitude higher than tritium, and radioactive strontium can enter the bone with calcium. The conversion factor is only slightly lower than iodine, but also much higher than tritium. Since Fukushima nuclear wastewater contains a large number of radionuclides, if the multi-radionuclide treatment system cannot clean them, it will inevitably affect marine life.

Of course, the ocean has a strong dilution self-purification capacity, but because of the long half-life of radionuclides, even low concentrations of radionuclides in the ocean may accumulate through food chain enrichment. In particular, offshore fisheries near Fukushima have detected excessive levels of radionuclides in Xu's Pingsong. In addition, the offshore is also a breeding ground for many pelagic fish, and radioactive materials will be pushed into the deep sea by ocean currents to be continuously diluted, but the high concentrations of radioactive materials enriched in aquatic organisms in offshore areas will also spread farther with the migration or food chain of young fish hatched in offshore waters, so even if the seawater has a strong dilution and absorption capacity, excessive radioactivity in offshore areas can also affect fisheries.

In response to this situation, the mainland has strengthened the control of aquatic products and agricultural products in and around Fukushima as early as after the Fukushima accident, and has also continued to detect aquatic products in other marine areas that may be affected.

Is discharging nuclear-contaminated water into the sea the only option? How credible is the IAEA?

Ren Hui: What are the treatment steps of Fukushima's contaminated water discharged into the sea? Is the contaminated water discharged into the sea different from the nuclear wastewater produced by normal operating nuclear facilities?

Zhang Zili: Nuclear contaminated water is different from nuclear wastewater. Any wastewater discharged from a nuclear power plant is called nuclear wastewater, in which the radioactive content is very small and the composition is simple. However, the contaminated water discharged from the Fukushima nuclear power plant passes directly through the core and comes into contact with a large amount of radioactive material, which is extremely high, complex in composition, and difficult to predict and detect.

In general, the condensate in the first circuit in contact with the reactor is forbidden to flow out, and needs to be treated by special methods, and even need to be stored for 50 years and slowly wait for most of the radioactive material with high radioactive activity to pass 10 half-lives, that is, decay to less than one thousandth of the initial amount.

According to Japan's Tokyo Electric Power Company, they treated the nuclear-contaminated water through ALPS (Multinuclide Removal Equipment), eliminating most of the nuclear elements except tritium, which were diluted and discharged. However, ALPS has high long-term operating costs, and some experts point out that more than 70% of the nuclear contaminated water treated by ALPS does not meet the discharge standards and needs to be treated twice, so it is difficult to determine whether its treatment is standardized, whether the results meet the standards, and whether it is reasonably supervised.

Fukushima Nuclear Power Plant (Source: Visual China)

Ren Hui: At the end of 2021, the International Maritime Organization and others proposed a regulatory motion, but the Japanese side rejected it, claiming that the ALPS scheme is relatively mature and does not require third-party participation. Is there a trend in Japan to circumvent third-party supervision? On July 4, the International Atomic Energy Agency announced on its official website on the 4th, believing that Japan's plan to discharge nuclear contaminated water into the sea meets international safety standards. What does the IAEA generally review when it conducts such assessments? How credible is it?

Zhang Yanyi: At present, Japan has not completely circumvented third-party supervision, but is backed by the International Atomic Energy Agency.

In accordance with the consensus reached by the Government of Japan and the IAEA in July 2021, expert missions from the IAEA will conduct several on-site visits to Japan to provide reliable assessments.

When conducting assessments, the IAEA will focus on three main aspects: first, the state of the nuclear-contaminated water that will be discharged after treatment; The second is to assess the safety of nuclear-contaminated water during the discharge process; Third, the radiation effects that nuclear contaminated water may cause to the human body and the environment.

Judging from the relevant statements made by the International Atomic Energy Agency before Japan's nuclear sewage was discharged into the sea, it basically maintained a neutral and technical attitude towards major countries, which has a certain credibility. However, Japan's statements and actions in the case of the discharge of contaminated water into the sea have caused public distrust and greatly reduced its credibility.

Ren Hui: From May 29 to June 2, the IAEA Task Force visited Japan again to conduct a comprehensive safety review of the Fukushima Daiichi Nuclear Power Plant Advanced Liquid Processing System (ALPS) treatment water discharge plan. Does this indicate a problem with the previous assessment?

Zhang: Previous assessments are likely to be problematic, but the Japan Atomic Energy Regulation Commission recently determined through a review that there is sufficient evidence that the monitoring sources for treated water include all radionuclides with radiation effects, and that any radionuclides that may pose significant radiation doses to the public or animals and plants have not been excluded from its assessment. The previously released evaluation report also did not have specific test data, and the number of samples collected was also questionable, so its previous evaluation report could not prove its effectiveness.

International Atomic Energy Agency (Source: Visual China)

Ren Hui: Is direct discharge of contaminated water the only option for the Japanese government? What alternatives are there?

Zhang: Draining contaminated water into the sea is not the only option for Japan, there are many other alternatives, including formation injection, steam emissions, hydrogen emissions and underground burial. Formation injection and underground burial are disposed of within the territory of Japan, which has no impact on other countries, but has a high economic cost; Steam emissions and hydrogen emissions generate solid waste, which requires further treatment and disposal, which is economically costly, and secondary waste affects Japan's own environment. Therefore, the reason why Japan abandons other, more reliable options and chooses to discharge directly into the sea is because it is "the most economical" and "most convenient".

3. Does Japan's discharge of nuclear-contaminated water into the sea violate international law? Is there room for manoeuvre?

Ren Hui: There is no precedent in the world for discharging water polluted by nuclear accidents into the ocean, so is Japan really taking measures to drain the sea out of "money-saving considerations"? Does Japan's discharge of nuclear-contaminated water violate relevant international law? Does the relevant law have a strong effect on it?

Zhang Yanyi: Japan's discharge of nuclear-contaminated water is a serious violation of international law. According to the United Nations Convention on the Law of the Sea, the discharge of nuclear-contaminated water into the sea seriously violates the basic principles of marine ecological environmental protection embodied in international law. This requires countries to join forces, actively study, collect evidence, and file lawsuits to protect rights.

At present, however, we cannot balance Japan through international law litigation. The law is laggy, i.e. legal proceedings can only be initiated after the actual damage has occurred and there is a positive strong causal relationship between the actual damage and the cause of the cause. Since Japan has not yet discharged nuclear-contaminated water, we cannot sue.

This time the discharge of nuclear-contaminated water has built a meticulous firewall. By building a detoxification pipeline, the Japanese side cleverly circumvented the London Dumping Convention by diverting water to a distance of 1 km from the coast. The Convention provides for dumping by means of ships or artificial platforms, and the use of submarine pipelines precludes the applicability of the Convention. This well-planned, step-by-step planning is chilling.

(Source: Asia Today)

Ren Hui: At present, can the international community resort to law to stop Japan's discharge of nuclear-contaminated water into the sea? If not, what else can be done to stop Japan's nuclear-contaminated water from being discharged into the sea? How should the international community act?

Zhang Yanyi: First of all, Japan's Fukushima nuclear wastewater discharge into the sea and the impact and harm caused by it involve a series of principles, procedures and issues of international law, which can be applied. This requires countries to unite to actively study, collect evidence, and file lawsuits to protect rights.

Through recourse to the International Court of Justice and the International Tribunal for the Law of the Sea, the long-term significance of achieving conviction and accountability for Japan's nuclear contaminated water discharge plan is far greater than the practical significance, which will help all parties clearly understand their environmental protection obligations and reach a broader consensus on marine environmental protection.

At the same time, due to the difficulty of collecting evidence in international litigation, the long litigation time and many obstacles, the international community can also adopt other means, such as diplomatic means and public opinion means, combined with legal means to protect its own rights and interests.

4. What is the impact of the discharge of nuclear contaminated water into the sea on all walks of life? How can ordinary people respond?

Ren Hui: According to media reports, the price of sea salt in South Korea has skyrocketed due to the people's frantic rush to buy salt due to the impact of nuclear sewage. Apart from fishing, what other industries may be affected by this discharge of nuclear wastewater?

Zhang Yanyi: From the perspective of people's livelihood, we may also encounter the rush to buy salt in South Korea. At the same time, seafood prices will soar in the short term before the nuclear-contaminated water is officially discharged.

From the perspective of national industry, Japan, as the world's second largest country in distant-water fishing, will inevitably suffer from its own advantageous industries. The mainland's distant-water fishing volume has long ranked first, and it is bound to be greatly affected in the field of marine fishing.

In addition, fisheries, seafood industries, sea salt industries and other industries involving marine food will be affected, and even the general food industry, medicine and health products industry, cosmetics industry and other industries involving agriculture, industry and commerce, tourism and other industries will be affected. Its impact is so wide and far-reaching that it is foreseeable that it will cause immeasurable economic losses.

Ren Hui: Recently, many netizens have used nuclear radiation detectors to detect the radiation index of cosmetics. How much radiation hazard are cosmetics? Will the discharge of Fukushima nuclear sewage affect Japanese cosmetics?

Zhang Zili: After cosmetics and skin care products are absorbed by the skin, only a small dose is required to cause obvious harm to the human body. Especially for facial skin care products, once radioactive substances pass through the blood-brain barrier, the radiation to the brain is unimaginable.

Unlike food safety reviews, many of the risks of cosmetics are unknown, and there is a lack of relevant laws and regulations to review raw materials and origins. Many of the world's cosmetics come from Japan, and the discharge of nuclear sewage into the sea will also have a great impact on the beauty industry.

So many people ask me if Japanese seafood can be eaten after the discharge of Japan's nuclear contaminated water, and I think it is okay, because the country has relevant standards that will provide gatekeeping. But if I ask if Japanese skincare products and cosmetics can be used, I think we should be vigilant.

Ren Hui: In addition to cosmetics, what other aspects do we need to be vigilant and pay attention to? For example, the Seoul Municipal Education Agency in South Korea decided that when Japan's plan to discharge nuclear-contaminated water is actually implemented, it will conduct comprehensive radiation testing of school meals in Seoul to ensure the safety of food ingredients. Do mainland coastal areas also need to strengthen nuclear radiation detection for catering?

Zhang Yanyi: In addition to food, medicine, and cosmetics, products produced in Japan that have direct contact with the human body, such as cups, feeding bottles, clothing, etc., all carry the risk of carrying nuclear radiation, and long-term contact with the human body may cause adverse effects, which need to be noted.

At present, the incident of discharging nuclear contaminated water in Japan has aroused widespread concern in China, and scientific detection of nuclear radiation content is very beneficial to food security, which can effectively protect the health and safety of mainland people, and can also reduce the actual panic of mainland citizens about the discharge of Japanese nuclear contaminated water into the sea.

Ren Hui: If Japan starts discharging nuclear-contaminated water into the sea, what countermeasures do you propose the mainland take? What are the relevant measures taken by the local residents of Japan?

Zhang Yanyi: The mainland should join hands with other countries and regions, such as South Korea, Russia, Pacific island countries and other interested countries that will be the first to be affected by the discharge of Japan's nuclear-contaminated water into the sea, actively carry out communication and exchanges, strengthen contacts, exchange information on whether there is a problem, jointly file motions for advisory opinions in relevant UN bodies, and be prepared to resort to international judicial institutions to claim accountability for Japan. During this period, the collection of scientific evidence will be intensified, basic information such as fishery statistics, catch assessment and improved or intensive monitoring of nuclear-related data in coastal areas will be intensified in order to compare before and after and cross-compare with foreign data, calculate the amount of claims and submit them as evidence. Drawing on South Korea's practice and experience, we should urgently introduce or revise nuclear-related laws and regulations, increase the scope and frequency of domestic monitoring of radioactive materials, and provide a domestic legal basis for coping with Japan's discharge of nuclear-contaminated water.

Local residents and environmental protection organizations in Japan strongly oppose the discharge of Japan's nuclear-contaminated water into the sea, and many Japanese non-governmental organizations have jointly launched many rallies and marches against the discharge of the sea, and carried out joint signing activities. In addition, local local governments and aquaculture households in Japan will also participate in monitoring the concentration of tritium before and after wastewater discharge, and effectively grasp the data of nuclear contaminated water discharge, and Japanese residents and organizations will also file related lawsuits against the Japanese government or Tokyo Electric Power Company.

On May 16, 2023, in Tokyo, Japan, people demanded an end to plans to discharge nuclear-contaminated water into the sea. (Source: Xinhua News Agency)

Ren Hui: According to Japanese officials, after two weeks of testing, it is expected that the contaminated water will be released in early July. How should we ordinary people respond to this situation?

Zhang Yanyi: To correctly understand Japan's nuclear contaminated water discharged into the sea, we must pay attention to and oppose it, but there is no need to panic. To believe that our government can maximize the safety of the lives of mainland people, our country has abundant resources, taking the recent South Korean "hoarding of salt" caused by salt shortage as an example, on the contrary, the mainland has abundant salt resources, salt production scale is large, can meet the domestic market demand. And most of China's table salt is mineral salt, mainly from salt lakes and salt mines, which is less affected by nuclear contaminated water. Therefore, we do not need to panic too much, we must believe that the country can guarantee our normal life and reduce the impact of nuclear contaminated water on our daily life.

Zhang Zili: As a community with a shared future for mankind, no one can stay out of it. We need to strengthen coastal monitoring and do a good job in marine ecological security supervision, so as to maintain a calm and cautious attitude to closely monitor the situation.

Guest Introduction:

Organizer: Wang Zirui

This article is an exclusive contribution of Tencent News "Let's Talk Together", unauthorized media reproduction is prohibited, but welcome to forward to personal circle of friends.