Safety review by the IAEA

Safety review by the International Atomic Energy Agency (IAEA)

  • In light of request from Government of Japan following the Basic Policy announced in April 2021, the IAEA conducted technical reviews of the safety of all related aspects of the handling ALPS treated water to assess consistency with relevant international safety standards. The Task Force* included experts from the IAEA Secretariat and internationally recognized independent experts.
  • A comprehensive report that summarized the results of the review was released in July 2023.
  • The IAEA is committed to being involved before, during, and after the discharge of ALPS treated water into the sea. *International experts from Argentina, Australia, Canada, China, France, the Marshall Islands, the Republic of Korea, the Russian Federation, the United Kingdom, the United States and Viet Nam.

About IAEA (International Atomic Energy Agency)

  • The IAEA was established as a United Nations related organization in 1957 and is the international organization promoting for cooperation on nuclear power through out the world.
  • IAEA sends reviewers to countries all over the world to confirm that nuclear power is being used for peaceful purposes. Furthermore, IAEA establishs international standards for the safe use of nuclear power, and provides their expert knowledge to nations looking to engage in nuclear power generation.

Director General
Rafael Mariano Grossi

Main gist of the comprehensive report

  • The approach to the discharge of ALPS treated water into the sea, and the associated activities by TEPCO, NRA, and the Government of Japan, are consistent with relevant international safety standards.
  • The discharge of ALPS treated water, as currently planned by TEPCO, will have a negligible radiological impact on people and the environment.

IAEA comprehensive report
on the safety review
of the ALPS treated water

Main items assessed during the IAEA review

❶ Assessment of Protection and Safety Aspects of Handling of ALPS Treated Water

Safety aspects such as the charactaristics of ALPS treated water and the safety of the discharge process have been assessed.

  • Site visit by the IAEA

  • Review meeting

❷ Regulatory Activities and Processes

Nuclear Regulation Authority's (NRA) handling of this issue as the independent regulatory body responsible for nuclear safety has been assessed.

❸ Independent Sampling, Data Corroboration and Analysis

In order to corroborate the analysis results, the samples of ALPS treated water taken in the presence of the IAEA were analyzed by the IAEA in its laboratories and in third-party laboratories in Switzerland, France, the United States, and the Republic of Korea, and interlaboratory comparison was conducted.

Participating Laboratories


・IAEA Marine Environment Laboratories, Radiometrics Laboratory (RML), Monaco

・Terrestrial Environmental Radiochemistry Laboratory (TERC), Seibersdorf, Austria

・Isotope Hydrology Laboratory (IHL), Vienna, Austria

■ The Third-Party Laboratories

・Spiez Laboratory (LS – Labor Spiez), Switzerland

・Institut de Radioprotection et de Sûreté Nucléaire (IRSN), France

・Los Alamos National Laboratory (LANL), United States of America

・Korea Institute of Nuclear Safety (KINS), Republic of Korea

  • Sampling of ALPS treated water

  • Sampling and pretreatment process




Release of the report on the first safety review mission (after the discharge)



First safety review mission (after the discharge)


Release of the IAEA comprehensive report


Comprehensive review mission on the discharge of ALPS treated water

Release of the report on the first interlaboratory comparison result

Release of the report on the second regulatory review mission


Release of the report on the second safety review mission


Second regulatory review mission



Release of the Report on IAEA’s Independent Sampling, Data Corroboration, and Analysis Activities


Second safety review mission


Release of the report on the first regulatory review mission


Release of the report on the first safety review mission


First regulatory review mission


First safety review mission



IAEA and the Government of Japan sign terms of reference governing the IAEA review


The Government of Japan announces its Basic Policy on the handling of ALPS treated water