FAQ

(2) Is ALPS treated water really safe?

　ALPS treated water is significantly diluted with seawater before discharge. The tritium concentration after dilution is less than 1/40 of the safety standard (or 1/7 of the WHO drinking water standard).

　Because the water satisfies safety standards before it is discharged and the total amount discharged is also controlled, there is no concern about effects on human health or the environment. Specifically, the impact on humans is about one-thousandth of the radiation dose received from a single dental x-ray. In addition, we take every precaution to ensure safety by carefully checking whether any significant changes in the concentration of radioactive materials in the sea have occurred before and after the discharge. (Source: METI)

　The International Atomic Energy Agency (IAEA) has concluded, in its Comprehensive Report published on July 4th, that “the discharge of the ALPS treated water into the sea, as currently planned by TEPCO, will have a negligible radiological impact on people and the environment”.(Source: IAEA)

→For more information, please watch this video

(3) Is there a difference between “ALPS treated water” and “contaminated water”?

　“ALPS treated water” is not the same as “contaminated water”. There are two different types of water on the Fukushima Daiichi site. One is “contaminated water” generated on the site, and the other is “ALPS treated water” which has almost all radioactive materials removed except tritium. “Contaminated water” will never be discharged into the sea. To avoid public confusion, it is important to have an understanding of the terminology. The IAEA has also pointed out the distinction between these terms.

(4) Is ALPS treated water drinkable?

　Through ALPS treatment, radioactive materials other than tritium are purified below regulatory standards, and tritium is diluted with seawater to a concentration level below 1/7 of the WHO standard. Therefore, even if you drank the water, there would be no health effects from radiation. Meanwhile, it is not the practice of any country to drink the water discharged from nuclear facilities.

(5) What is the “contaminated water” being generated at the Fukushima Daiichi Nuclear Power Station?

　“Contaminated water” refers to water that contains highly concentrated radioactive substances that has been generated as a result of the Fukushima Daiichi Nuclear Power Station accident. Inside the reactors of Fukushima Daiichi Nuclear Power Station Units 1~3, there is fuel that melted and solidified during the accident (fuel debris). This fuel debris is being kept cool by continuously spraying it with water, but when this water comes in contact with the fuel debris it is exposed to the highly concentrated radioactive substances and becomes “contaminated water.” This “contaminated water” that contains highly concentrated radioactive substances accumulates inside the reactor buildings, and when it mixes with groundwater or rainwater flowing into the buildings, even more “contaminated water” is produced.

　The “contaminated water” is being treated/purified to reduce the concentrations of radioactive substances using multiple types of equipment such as ALPS. After risks have been sufficiently reduced in this manner, it is stored in tanks on site as ALPS treated water, etc.. (Source: TEPCO)

→For more information, please watch this video

(6) Why must ALPS treated water be discharged?

　The number of giant tanks where ALPS treated water is stored in the area of the Tokyo Electric Power Company’s Fukushima Daiichi Nuclear Power Station is increasing and already exceeds a thousand. In order to safely proceed with the decommissioning work at the Fukushima Daiichi Site, which is about to begin picking up speed, the space is needed for the construction of new facilities. It will be necessary to discharge ALPS treated water and reduce the number of tanks. Some people have expressed concerns that the tanks may collapse in the event of a disaster, and that the existence of the giant tanks itself may be a cause of reputational damage. For these reasons, discharging the ALPS treated water and reducing the number of giant tanks is essential work in order to proceed with safe decommissioning and reconstruction of Fukushima. (Source: METI)

(7) Is it possible to store or discharge ALPS treated water outside of the Fukushima Daiichi Nuclear Power Plant site?

　The decommissioning of the Fukushima Daiichi Nuclear Power Plant is essential for the reconstruction of Fukushima. Every day, decommissioning measures are taken to reduce risks on site, while preventing increase in risks at the surrounding areas. Both transferring the treated water and storing it in tanks outside the site are the activities which increase risks. In addition, it is necessary to obtain understanding from related local governments and local residents, which takes a considerable amount of time. (Source: METI)

(8) What is the difference between the water discharged from Fukushima Daiichi and from other nuclear facilities?

　The water present in the buildings of the Fukushima Daiichi Nuclear Power Station contains radioactive materials (e.g., cesium and strontium) that are not normally contained in wastewater from ordinary nuclear power plants, but these radioactive materials will be removed by ALPS until the concentration level is below the regulatory standards. In addition, these radioactive materials are also contained in wastewater from reprocessing plants in various countries and regions, and are similarly discharged in compliance with the regulatory standards of each country.

　Regulatory standards are set based on established international standards and are determined by the sum of the radiological impacts of all radioactive materials contained, regardless of the type of radioactive materials and whether nuclear power plants have experienced an accident or not. (Source: METI)

(2) Does tritium not bioaccumulate?

　Bioaccumulation is a phenomenon in which a substance is taken into the body of an organism, accumulated without being discharged, and then taken up by higher organisms in the food chain, and this process is repeated, resulting in further concentration. However, no research to date has confirmed that tritium in the water state causes bioaccumulation. This is because tritium, like water, is mostly discharged from the bodies of living organisms and does not accumulate in the body. (Source: METI)

(3) Even if tritium by itself has no health effects, can tritium be organically bound to become a dangerous substance?

　In some organic compounds made of carbon and hydrogen, hydrogen atoms are replaced with tritium (organic bond). Such substances are called "organically bound tritium (OBT)". Even if OBT is temporarily taken into the body, most of it is eliminated from the body in about 40 days, and even if it remains for a long time, it is reduced by half in about one year. Due to the difference in the period of time that OBT remains in the body, the health effects of OBT are 2 to 5 times higher than those of tritiated water. However, the health effects of tritiated water are originally extremely small at 0.000000019 mSvper Bq, so the health effects are not particularly significant even if the dose is 2 to 5 times higher. Compared to the health effects of cesium, for example, the health effects of tritiated water are about 1/300th of those of cesium. (Source: METI)

(4) How is the regulatory standard for tritium (60,000 Bq per L in water) established?

　The national regulatory standard for environmental discharge of water containing tritium (60,000 Bq per L) is set based on a concentration level that would result in an annual exposure of 1 mSv if approximately 2 liters of water from a nuclear facility's discharge outlet were drunk at that concentration level every day for 70 years.

[Reference]

　The annual average exposure dose from natural radiation (Japan) is about 2.1 mSv per year. The WHO standard (10,000 Bq per L) is used to determine whether radiation protection measures are necessary for drinking water.

(Source: TEPCO)

(2) Who conducts the IAEA safety review?

　The IAEA has established a task force that includes members of the IAEA Secretariat and international experts from 11 countries(note), and the safety review has been conducted by this task force.

　(note) 11 countries: Argentina, Australia, Canada, China, France, Marshall Islands, Republic of Korea, Russian Federation, United Kingdom, United States, and Vietnam.

(Source: IAEA)

(2) What efforts is Japan making for food safety?

　After the accident at TEPCO's Fukushima Daiichi Nuclear Power Plant, in areas where the effects of radioactive materials have been confirmed, farmland decontamination, measures to reduce the transfer and absorption of radioactive materials into agricultural and livestock products, and management of fertilizers, soil improvement materials and culture media are being implemented. In addition, any food that exceeds the standard values for radioactive materials in Japan, as determined by pre-shipment inspections, etc., will not be distributed in Japan or overseas. Furthermore, "shipment restrictions" are imposed when foods exceeding the standard values are considered to have a regional spread, and "intake restrictions" are ordered when extremely high concentrations of radioactive materials are detected. These measures ensure the safety of Japanese food products.

　The International Commission on Food Standards (Codex Committee), established by the Food and Agriculture Organization of the United Nations (FAO) and WHO, sets guideline levels for radioactive materials in foods as international standards, while other countries including the United States and the EU set national standards. These standards are set to keep the deposited effective dose (so-called internal exposure) from ingestion of food below a certain level, which is 1 mSv/year in the case of the Codex Committee, Japan, the EU, etc. This is a value that the International Commission on Radiological Protection (ICRP) has determined that no significant dose reduction can be achieved even if further radiation protection measures are taken. Based on this, the standard values for radioactive materials are finally set after assuming the contamination rate of food products distributed in each country and region.

(3) How do international organizations evaluate the safety of Japanese food products?

　The safety of Japanese food products has been evaluated by international organizations for the appropriate inspection and control measures that Japan has implemented. A joint team from the FAO and the IAEA reported in July 2019, that "the Joint FAO/IAEA Division understands that measures to monitor and respond to issues regarding radionuclide contamination of food are appropriate, and that the food supply chain is controlled effectively by the relevant authorities." The report is available on the IAEA website（link).

(2) Had there ever been any consideration on disposal of ALPS treated water by methods other than discharge into the sea, such as "geologic injection" or "concrete solidification"?

　The national task force examined the issue and found that "there are many challenges from regulatory, technical, and time perspectives as realistic options.”

　In December 2013, an IAEA expert team advised that "all options should be examined" for handling of the ALPS treated water. In response to this advice, the government established a task force to examine various options, including "geological injection" and "underground burial" as technically feasible disposal methods. In response, the government established a task force to examine various technically feasible disposal options, including "geological injection" and "underground burial.

　In the "geological injection" method, ALPS treated water is to be injected into a crevice in the geological formation and there sealed in. This requires a suitable geological formation (reservoir) for injection. It has not known if there is a suitable geological formation under or near the Fukushima Daiichi Nuclear Power Station. Without suitable formation, geological injection cannot be performed. The national task force also stated that it is difficult to confirm the safety of injected water because there is no established method for long-term monitoring, and that new regulations and standards will need to be established depending on the disposal concentration.

In the "underground burial" method, ALPS treated water is to be mixed with cementitious solidification material. Later, it will be poured into a concrete pit, solidified, and buried underground. According to the report of the ALPS subcommittee of the Government of Japan, the following are the problems with underground burial by concrete solidification: (1) water containing tritium evaporates due to heat generated by solidification, (2) new regulations may be required, and securing a disposal site will be an issue. (Source: TEPCO)