Q1: What is “treated water”?

A: “Contaminated water” and “treated water” are different. “Contaminated water” contains a large amount of radioactive materials, and has been generated in buildings every day since the accident. “Treated water” is water in which most of radionuclides are removed by purification. However, radioactive material “Tritium” cannot be removed by purification, and remains in the treated water.

Q2: What is “contaminated water”?

A: The water for cooling fuel debris gets contaminated and stagnates in the buildings. The level of groundwater outside is controlled to be higher than that of water inside the buildings, to prevent the contaminated water from flowing out. As a result, groundwater keeps flowing into the buildings and contaminated water keeps generating in the buildings every day.

Q3: Why is disposal of ALPS treated water needed?

A: At FDNPS, water used for cooling fuel debris (contaminated water) has been treated, and the treated water is stored in tanks on site. Storage tanks are predicted to reach full capacity around summer of 2022. Decommissioning of FDNPS is essential for Reconstruction of Fukushima. Until the end of decommissioning, tanks are needed to be removed. Therefore, the issue on disposal of treated water cannot be left forever. 

Q4: Why are two options suggested by the expert committee feasible?

A: “1) Vapor release” and “2) discharge into the sea” are suggested by the committee.
Both option 1) and 2) are recommended to be realistic, because of the precedents and track records for them. “2) Discharge into the sea” can be implemented more reliably, considering the ease of discharge facilities operation and proper monitoring methods.
 The International Atomic Energy Agency (IAEA) acknowledged that the options suggested by expert committee is “based on a sound scientific and technical basis of analysis”.


Q5: Is it possible to store or discharge treated water outside of Fukushima Daiichi NPS (FDNPS)?

A: Decommissioning of FDNPS is essential for reconstruction of Fukushima. Every day, decommissioning measures are taken to reduce risks on the site, while preventing increase in risks at the surrounding areas. Both to transfer the treated water to outside the site and to store the treated water in tanks outside the site are the activities which will increase risks outside the site. In addition, it is necessary to obtain understanding from related local governments and local residents, which takes a considerable amount of time. Regarding offshore release, to carry the treated water and discharge it from the marine vessel is prohibited by international treaty (London Convention).

Q6: Is it possible to store in intermediate storage facilities?

A: The land for the intermediate storage facilities were provided by the landowners for the facilities’ use only. Therefore, it is difficult to use for other purposes.
 (Ref.)  Intermediate storage facilities are the facilities located at areas adjacent to the FDNPS, in order to temporarily store soil and others which have been collected by decontamination work in Fukushima, and which contain radioactive materials released from the FDNPS at the time of accident.

Q7: What are the steps toward handling of ALPS treated water?

A: Considering the report from expert committee, the GOJ will decide its basic policy including measures against possible reputational damage, after hearing the opinions of a wide range of the parties concerned including local communities. Based on the governmental basic policy, TEPCO will determine the specific method and will obtain an approval from the Nuclear Regulatory Commission, and then will start disposal.

Q8: What is tritium?

A: Tritium is a relative of hydrogen that emits weak radiation. Tritium exists naturally and is found in rain water, sea water, tap water, and inside of human body as a form of tritiated water. Tritium is ingested into the human body via drinking water and excreted from the body, and then circulates in nature as the water does. It has not been confirmed to be accumulated in humans or specific organisms.

 * Tritium concentration for tap water: 1 Becquerel/L
 * Amount of Tritium in human body: tens of Becquerel

Q9: Can tritium be removed?

A: It is very difficult to remove tritiated water from water, as it has the same properties as water. Experts have concluded that there is no tritium separation technology that is immediately applicable to treated water with low concentration and large volume.
IAEA (International Atomic Energy Agency) is “not aware of a solution currently available for the separation of tritium commensurate with the concentration and the volume of treated water”.

Q10: Does the treated water contain radioactive materials other than tritium?

A:  About 70 % of the treated water stored in tanks contains radionuclides other than tritium at the concentration exceeds regulatory standards.

  * In early years, the ALPS treatment has been carried out by prioritizing the volume of water treatment to quickly reduce the radiation impact to outside the site. There were also cross filter permeate troubles and other troubles. 

Since FY2020, re-purification of the treated water will be commenced to meet the regulatory standards other than tritium. In the case of releasing to the environment, the treated water will be sufficiently diluted also to meet the regulatory standard for tritium.

Q11: How much is the radiation impact of treated water release?

A: The impact of the radiation to human health as a result of the discharge is considerably small. Even if the entire amount of the ALPS treated water containing tritium and other radioactive material were to be disposed of in one year, the impact would be no more than 1/1000 of the exposure impact of natural radiation in Japan.

Q12: What regulatory standards are applicable to the discharge from Fukushima Daiichi NPS (FDNPS)?

A: Japan’s regulatory standards for discharge is set in compliance with the international standards known as publications of International Commission for Radiological Protection (ICRP), keeping additional public radiation dose not exceeding 1mSv/year. The regulatory standards for Tritium discharge stipulated in the ordinance of the Reactor Regulation Act is:

 *Less than 60,00 Bq/L-water for Tritium discharge into the sea; and
 *Less than 5Bq/L-air for Tritium release to the atmosphere.

Q13: What kind of countermeasures for possible reputational damage will be taken?     

A: The safety of foods produced in Fukushima is confirmed before market distribution by inspection. As the GOJ reaches out and as the fact is known by overseas government, import regulations have been eased and lifted. When the GOJ decides its policy on treated water, countermeasures for reputational damage will be strengthened in such areas as explaining scientific safety and developing sales channels.

Last updated:2020-09-10