Source: CCTV News Client
On March 11, 2011, an earthquake measuring 9.0 on the Richter scale struck northeastern Japan. The massive tsunami triggered by the strong earthquake flooded the Fukushima Daiichi Nuclear Power Plant site, causing power interruptions, paralyzing the cooling system, and core meltdowns in units 1, 3 and 4, and three nuclear reactors. In order to cool the reactor, the injection of seawater into the atomic furnace began on March 12. The resulting amount of contaminated water has accumulated to 1.3 million tons so far, and it continues to increase every day.
On June 12, 2023, Tokyo Electric Power Company, the operator of the Fukushima Daiichi Nuclear Power Plant, began trial operation of equipment related to the discharge of contaminated water. How to deal with the contaminated water generated by the Fukushima Daiichi nuclear power plant accident has always been the focus of international attention. On April 13, 2021, the Japanese government officially announced plans to discharge contaminated water from the Fukushima Daiichi Nuclear Power Plant into the ocean.
On 4 July 2023, IAEA Director General Grossi held a press conference in Japan to unveil the conclusions of his review of the Fukushima nuclear contaminated water discharge project, which concluded that Japan's plan to discharge the treated water into the sea in Fukushima meets international safety standards. On July 7, the Japan Atomic Energy Regulation Commission issued the acceptance certificate to the Fukushima Daiichi Nuclear Power Plant nuclear contaminated water discharge facility to Tokyo Electric Power Company on the same day.
What nuclides are contaminated with the water in the reactor? How harmful is it to humans and marine life? Can the nuclear material in the contaminated water be completely removed?
To find out, we interviewed several experts, university professors and members of the media, and we were interviewed by representatives of Japan's Nuclear Regulation Commission.
Yuaki Koide, 73, was an assistant professor at the Nuclear Reactor Laboratory at Kyoto University in Japan before his retirement.
Reporter: What is the difference between the wastewater discharged from the laboratory, the industrial wastewater from the operating nuclear power plant, and the nuclear-contaminated water treated by the multi-nuclide removal unit at the Fukushima Daiichi Nuclear Power Plant?
Hiroaki Koide: Nuclear fission products produced in a functioning nuclear power plant, which the Japanese call "death ashes", are enclosed inside fuel rods or fuel plates, and only a small part of them enter the water. But in the Fukushima accident, all radioactive material that should have been enclosed in fuel rods was exposed. The fuel rods themselves have melted, and the radioactive material produced has continuously seeped into the water, forming contaminated water.
Hikaru Amano, a researcher at the National Japan Nuclear Power Agency (NISA), is a well-known expert in environmental radiation.
Reporter: What is the difference between the nuclear pollution at the Fukushima Daiichi Nuclear Power Plant and the industrial wastewater discharged from ordinary nuclear power plants?
Hikaru Amano: In the case of ordinary nuclear power plants, the wastewater discharged mainly contains tritium, but after the Fukushima Daiichi nuclear power plant accident, the nuclear fuel melted down, resulting in nuclear fuel residue. Fuel residue contains more than 1,000 kinds of nuclides, and groundwater and rainwater come into contact with these thousands of nuclides to form nuclear-contaminated water, which is fundamentally different from the wastewater of general nuclear power plants.
Sean Bernie is a senior nuclear environmental expert in the UK. Since the mid-90s of the 20th century, he has worked in Fukushima and other places for nearly 30 years to monitor the environmental safety indicators of Japan's major nuclear power plants. After the Fukushima nuclear accident, he visited the Fukushima disaster area many times and continued to pay attention to the aftermath of the accident.
Reporter: TEPCO has been citing data on the discharge of nuclear wastewater by various countries to show that the way they discharge the sea is in line with international practice. Do you think that Fukushima nuclear contamination is the same as the wastewater of nuclear power plants in other countries?
Sean Bernie: It's fair to say no, it's completely different. This is because the contaminated water in Fukushima is water that has come into contact with the melted nuclear fuel, which is the nuclear fuel in the reactor. This is not normal nuclear power plant operation. The Japanese government's simple comparison between the two is dishonest and incorrect.
In March 2012, one year after the Fukushima Daiichi nuclear accident, TEPCO measured for the first time the composition and concentration of radioactive materials contained in contaminated water. The results showed that there were as many as 64 nuclides with excessive concentrations.
Yuaki Koide: Of all the radioactive substances, I think the most harmful to humans is a radioactive substance called cesium-137. The radioactive energy released by tritium is 18.6 kiloelectronvolts. In other words, it is a thousand or ten thousand times more energetic than the molecular bonds of living organisms. Of course, other radioactive materials are even more energetic. Carbon 14 should be 850 kiloelectron volts, while cesium 137, which emits gamma rays, has 661 kiloelectron volts. So I think it's fair to say that carbon-14 is more dangerous than tritium and cesium-137.
When people's attention is attracted by the large number of "cesium" and the "tritium" that cannot be removed, some experts keenly point out that there are some potential nuclides that have not been detected, and their harm is not to be underestimated.
Sean Bernie: We saw some data from TEPCO, which is known to have been 62 different types of radioactive material in the contaminated water at the time of the accident, in addition to carbon-14 and tritium. But they still did not make a complete description of all the radioactive material in the tanks. In fact, only about 20% of the jugs have been substantially inspected.
Hikaru Amano: The source of the contaminated water is from nuclear fuel residue, which contains more than 1,000 nuclides. It is obvious that many of these nuclear fuel residues dissolve in water when they come into contact with water.
Reporter: Do you think there are any problems in TEPCO's current technology and method of detecting the composition of "treated water"?
Hikaru Amano: There is a problem. Of course, simple nuclides that can be measured will be published, but there are many more nuclides that are difficult to measure. For example, radiocarbon, iodine-129, there are some nuclides that should be measured, and I hope that these nuclides will also be detected correctly.
Reporter: It is said that the polluted water contains actinides, what do you think?
Hikaru Amano: I think that's completely true. Originally, the No. 3 reactor at the Fukushima Daiichi Nuclear Power Plant used so-called MOX fuel. In addition to uranium, plutonium was used as fuel.
Wang is a professor at the School of Radiation Medicine and Protection at Soochow University and a Ph.D. in the Center for Actinide Elements at the University of Notre Dame. He led the State Key Laboratory to analyze and study the principles and properties of multinuclide removal devices from the perspective of materials science.
Reporter: Can it be understood that there are some ingredients that are difficult to detect in terms of current science and technology?
Wang Yanwo: Because there are some nuclides, although its amount is very small, its specific activity and radioactive activity are low, its detection is difficult, and it will be interfered by coexisting nuclides. A nuclide like neptunium 237, its half-life is 2.17 million years, its radioactivity is very low, but such a very low amount, its toxicity is very high.
Hikaru Amano: There is also the element tellurium, which is comparable in toxicity to potassium cyanide, but TEPCO does not mention tellurium at all, nor does the Nuclear Regulation Commission mention it. There are tens of kilograms of tellurium in the nuclear fuel residue, which I think is very dangerous.
Reporter: Are these toxic elements not included in the 64 nuclides?
Hikaru Amano: Yes, not included.
Reporter: Why are obviously dangerous elements not included?
Hikaru Amano: Telluium is a stable element in a sense, but the Tokyo Electric Power Company and the Nuclear Regulation Commission are only focusing on radioactive elements right now, and I think that's why it's not included.
Whether it is 64 nuclides or many more that have not been tested, it is indeed an indisputable fact that the nuclear contaminated water in Fukushima has been seriously contaminated with a variety of radioactive substances. Therefore, the Japanese government and Tokyo Electric Power Company decided to use a multinuclide removal device called "ALPS" to filter and purify nuclear-contaminated water.
So, what exactly is the performance and effectiveness of multinuclide removal devices? To what extent can such a high level of radioactive contamination be removed?
Jun Takeuchi is a member of Japan's Nuclear Regulation Commission, where he is responsible for the aftermath of the Fukushima Daiichi nuclear power plant accident.
Jun Takeuchi: The water we call polluted water has a high concentration of radioactive substances and must not be discharged. With treatment equipment such as the Multinuclide Removal Unit (ALPS), the radiation level of the water is reduced to a low enough level that it will be diluted and released into the ocean in the future.
Ryota Koyama, a professor at Fukushima University, is a member of the Japanese government's Subcommittee on Multinuclide Removal Device (ALPS) Processing.
Reporter: How was it actually decided to use a multinuclide removal device (ALPS) in the first place?
Ryota Koyama: I started thinking about the Multinuclide Removal Device (ALPS) from a very early stage, in 2012 and 2013, and the initial stage after the accident in 2011. But it takes time to scrap a reactor, so we were thinking about how to introduce machines to stabilize the cooling water.
Jun Takeuchi: The most important thing is to make sure that the radiation level of the treated water does not affect people and the environment outside the nuclear power plant. During the inspection, we confirmed that the radiation level was low enough, so it was approved.
Ryota Koyama: However, during periods when there was too much contaminated water, the filter could not be replaced, and as a result, the performance of the Multinuclide Removal Unit (ALPS) deteriorated significantly, and 70% of the 1,000 water storage tanks now contain nuclides other than tritium.
Unfortunately, however, the multinuclide removal device has encountered many problems from the very beginning. The first to discover and announce that the treatment effect of the multi-nuclide removal device did not meet the standard was some media people. Hebei Shinbun, one of the major local newspapers in eastern Japan, published a series of articles focusing on the treatment of nuclear-contaminated water.
Kino Longyi: Hebei Xinbao said that more than 60 times the required value was exceeded, and I re-investigated it myself. It turned out that the number of exceeded standards was a little more than reported.
Reporter: How did the specific situation and conclusions of these radioactive materials come about?
Tatsuyoshi Kino: There are a lot of data disclosed by TEPCO, so I searched for documents one by one, and there were still a large number of figures in the documents, and I searched one by one to confirm the necessary data, and it took about half a year.
Tatsuyoshi Kino is a journalist. Since the 311 earthquake, he has focused on tracking the Fukushima nuclear accident, attending every press conference held by TEPCO for six consecutive years, and using this experience to write three books to expose the truth behind the contaminated water of the Japanese government and TEPCO.
Reporter: How do you view TEPCO's way of disclosing data?
Ryuyoshi Kino: I think the problem is that the data is very difficult to understand. There is nothing wrong with making all the data public, but it does not mean that it is okay to make it public, but it is honest to make it easier for people who see the data to understand what kind of data is there, and make it easy for everyone to judge the data.
Reporter: Is it possible that this method of disclosure conceals any information?
Tatsuyoshi Kino: I don't know if there is a cover-up, but disclosing a large amount of data at the same time makes important data unobvious, so even if this disclosure method is considered to cover up information, there is no way. Of course, TEPCO's on-site employees know about the excess, and it is impossible not to know because they themselves look at the data.
Under the pressure of public opinion, in 2018, TEPCO disclosed the results of the multi-nuclide removal device for the first time as of August of that year.
Ryota Koyama: Before 2018, the situation was really unclear, but after that, it was announced that 70% of the concentration in 1,000 tanks exceeded the standard, and seventy percent of them contained other nuclides other than tritium, which was made public, which is different from before.
Reporter: Is it true that after the contaminated water at the Fukushima nuclear power plant is treated once by a multinuclide removal device (ALPS), 70% of the "treated water" does not meet safety standards?
Jun Takeuchi: Yes, TEPCO announced this, and we announced it. However, in daily operation, we will check whether the nuclides have been adequately removed, measure the radioactive substances contained in the treated water, and continue to check the performance of the multinuclide removal device (ALPS).
Koide: The introduction of the Multinuclide Removal Device (ALPS) was too hasty and not rigorous, so unfortunately, it cannot effectively remove radioactive material. For example, strontium 90, a radioactive substance, is 100 times higher than the national standard and is still highly polluting.
Reporter: After the first round of treatment by the Multinuclide Removal Device (ALPS), about 70% of the contaminated water still cannot meet the standard. Why is that?
Sean Bernie: It's a technical problem, to treat such a large amount of water, if you do it too fast, the filter that filters the radioactive material is likely to be blocked, resulting in less efficient removal of radioactive material.
Since this so-called "70% incident," TEPCO has changed the name of water from the original "tritium water" to "treated water" on its website.
Reporter: What is the difference between these two names?
Jun Takeuchi: It was Tokyo Electric Power Company that named it "tritium water," and we didn't use the word "tritium" because it was misleading. Of course, water contains elements other than tritium, so our government also uses the term "treated water".
Kino Ryuyoshi: I think it's playing with words. It is not wrong to say that it is treated water, but to say "treated water" is like saying that it does not contain any pollutants.
Hiroako Koide: The government and TEPCO are trying to deceive us with words like "treated water," and this is a joke. It's downright radioactive contaminated water. If it is not radioactive water, then why does TEPCO say that the water stored in the water tank should be diluted with seawater and discharged? If it is treated water, there is no need to dilute it.
The first round of filtration of the multinuclide removal device can be said to have failed. As a result, TEPCO purchased two more treatment plants that were said to be more accurate, and prepared to retreat the remaining 70% of the substandard nuclear-contaminated water. So what about the effect of the second treatment?
Jun Takeuchi: The remaining 70% is removed by secondary treatment with a multinuclide removal device (ALPS). Whether it is really removed, all nuclides will be carefully confirmed before being discharged into the sea. The presence of nuclides in the water will be measured to check whether there are any exceedences.
Reporter: Some experts said that even if secondary treatment is carried out, all radioactive materials cannot be removed.
Jun Takeuchi: As far as I know, 70% of the reasons [of non-compliance] are not that the multi-nuclide removal device (ALPS) is not performing, but that there is a failure or a priority problem, and as long as you make sure that you use it correctly, you can guarantee its performance. In a trouble-free state, adequate processing is possible.
Reporter: Can secondary treatment, that is, the second treatment through the multinuclide removal device (ALPS), solve the problem?
Yuaki Koide: The amount of radiation is too large, and in order to deal with polluted water, there have been many problems such as machine failures, repairs, workers exposed to radiation, and so on. So I think it will be difficult.
In September 2020, Tokyo Electric Power Company began a test to retreat 70% of the substandard contaminated water in the water storage tank. The sample size selected for this test was 2 out of 1,000 tanks, totaling 2,000 tons of nuclear-contaminated water.
Koide: People are worried about whether 2,000 tons is too little. I think that's really a problem. If all 1,000 water storage tanks were retreated, it would probably be more acceptable to most people. But in that case, it is difficult to achieve in terms of technology, cost and time.
After a month of purification, in October 2020, TEPCO announced the results of the secondary treatment of the 2,000 tons of nuclear-contaminated water, claiming that it basically met drinking water standards. Since then, these 2,000 tons of water have become a model water for various monitoring agencies.
Sean Bernie: There were 2,000 cubic meters of secondary treatment, and they said it worked. But that's less than 0.21 percent of the total amount of water that needs to be treated, and it may take more than once, but many times it can be treated repeatedly, but they don't explain, and no one from the Japanese government or the International Atomic Energy Agency explains the process.
Sean Bernie: So the fact that emissions will be below regulatory standards doesn't mean the environment will be protected. It simply means falling below regulatory standards, which are themselves the problem, allowing radioactive material to be released into the environment.
Hikaru Amano: Japanese law is called concentration regulation. So if it is diluted to a lower than standard discharge, there will be no problem, so many pollutant emissions in Japan are based on this concentration standard, and there is no total limit.
Reporter: There is information that the test results of the water treated by the Multinuclide Removal Device (ALPS) do not contain carbon 14.
Jun Takeuchi: We asked TEPCO if it included carbon 14. The determination of radioactive material has a "reduction value", which means that a certain amount must be reached before it can be detected. As a result, no value above the "reduction value" was detected, so carbon 14 was not removed as a removal object.
Experts pointed out that TEPCO's detection of the results of nuclear contaminated water treatment only contains radionuclides, while other elements that are chemically toxic to the human body are not within the scope of detection. This makes the test results of "treated water" even more untrustworthy.
Wang Yanwu: I particularly want to mention actinide nuclides, and we have done a comparative and systematic study of actinide nuclides. First, its toxicity is very high, not only its radiotoxicity, but also its chemical toxicity, once discharged into the ocean, its impact on the entire marine ecological security, it may be even greater than those just a few nuclides.
Reporter: What do you think of the statement that a small amount can be discharged?
Hikaru Amano: I don't agree with that because emissions will last for 30, 40, 50 years. No matter how small the amount of discharge, radioactive material accumulates on the seabed and on the seabed, because there are various organisms in the ocean, and they accumulate on these organisms.
The multinuclide removal device is a large and complex system, in addition to its own technical performance, there is another unavoidable problem, that is, the operation and operation of the multinuclide removal device. Because in the eyes of many people, including TEPCO itself, most of the problems that occurred in the first round of multi-nuclide removal were related to operation and operation.
So, in the next 30 or 40 years, will TEPCO's operation and management be reassuring to the public?
Kino Ryuyi: No matter how good the performance is, it will also cause problems if it is used improperly. I am more worried about the technical level of TEPCO itself, which uses the Multinuclide Removal Device (ALPS), than the Multinuclide Removal Device (ALPS) itself.
Reporter: Do you have any questions about TEPCO's inspection and maintenance capabilities?
Tatsuyoshi Kino: Yes, I'm skeptical of TEPCO's capabilities.
Interviewer: Why?
Tatsuyi Kino: There are many parts in a multinuclide removal device (ALPS) that need to be maintained and inspected, and one of them is the filter. At that time, the maintenance cycle of the filter was not determined, and after a few years, once TEPCO inspected the equipment, not one or two, but almost all the filters were broken. I asked TEPCO what was going on? TEPCO explained that if it breaks, it will be replaced. The periodic maintenance cycle should have been decided before it broke down and replaced before it broke. If you find a bad one, you will fix it - they say there is no problem with this way of repairing.
Reporter: If there are problems in the multi-nuclide removal device (ALPS), such as filter failure or other problems, can they be detected immediately?
Hikaru Amano: I don't think I can find out right away, because the treated water is stored in a water storage tank, and the radioactivity indicators in the storage tank must be tested to determine whether it has been treated. It's hard to spot the problem right away.
Ryota Koyama: After the accident at TEPCO, various problems arose, so people's trust in them was quite low. The people in the surrounding area are also worried about this, so I think the most important thing in the future is whether they can guarantee this.
Jun Takeuchi: Our committee does not allow them to emit like that. Emissions can only be discharged after it is confirmed that it is below the concentration standard, and we highlighted these standards in our review, and TEPCO follows these to handle it.
Hikaru Amano: Actually, there is another problem with the Multinuclide Removal Device (ALPS), which is the filtration device just mentioned. Of course, it is good that the filter unit can remove radioactive material, but now the problem is that there is almost no space to store the used filter device.
In order to gain the trust of the public, TEPCO has established a "Treated Water Portal". The website provides a simple explanation of the multinuclide removal device and other information related to the treatment of contaminated water, but does not disclose the real problems and difficulties to the outside world.
Reporter: How will TEPCO explain the information of the Multinuclide Removal Device (ALPS) in the future?
Tatsuyoshi Kino: I think the most important thing is to allow not only Tokyo Electric Power Company but also third-party organizations to enter the Fukushima Daiichi Nuclear Power Plant so that different people can verify it from different angles and different perspectives. It is necessary to establish such a system.
Wang: But on the issue of Japan's nuclear-contaminated water, its regulation is now open and opaque. So once this nuclear-contaminated water is discharged into the sea, how many non-tritium radioactive isotopes are discharged into the ocean, we do not have such information.
Hikaru Amano: Some nuclides have a very long half-life, so I think there will be accumulation in the future, of course, it may not have an immediate impact, and this discharge of contaminated water will not have an immediate impact, but the pollution will accumulate in the future.
Sean Burney: I'm really worried about Fukushima Daiichi, he's on the Pacific coast. In the 2011 accident, a large amount of radioactive material was released due to the melting down of nuclear fuel. There is currently no solution, radioactive material is still in contact with the environment, and perhaps they will start draining into the sea this year, but it is still far from truly solving the problems related to the Fukushima nuclear accident.
The Pacific Ocean is magnificent, but it has never been as peaceful as its name. Disasters, wars, and pollution have been eroding this large and silent body. How will the Pacific Ocean withstand and change, and what will happen to the people and ecosystems that live with it?