On March 24, 2025, the IAEA published a report of its results for the interlaboratory comparison (ILC) on the determination of radionuclides in ALPS treated water.
The IAEA compared analysis results among TEPCO, laboratories of the IAEA and those from China, Republic of Korea, Switzerland, and United States of America selected by the IAEA on ALPS treated water taken from measurement/confirmation tanks in June 2024 and released its result.
This is the third report following the results of the first interlaboratory comparison on ALPS treated water, published on May 31, 2023, and the second one published on January 30, 2024.
In the published report, the IAEA notes that TEPCO has the capability for conducting reliable and high-quality monitoring related to the discharge of ALPS treated water and concluded that TEPCO has demonstrated that they have a sustainable and robust analytical system in place to support the ongoing technical needs at FDNPS during the discharge of ALPS treated water.
The Government of Japan will continue to maintain close coordination with the IAEA in sharing information with the international community in a highly transparent manner and fostering better understanding of the safety of the discharge of ALPS treated water within both the domestic and international communities.
(Reference1) Related links
The IAEA Press Release
The report on the results for the IAEA's Third Interlaboratory Comparison on the Determination of Radionuclides in ALPS Treated Water (PDF)
Publication of the Results for the IAEA's Second Interlaboratory Comparison on the Determination of Radionuclides in ALPS Treated Water
Publication of the Results for the IAEA's First Interlaboratory Comparison on the Determination of Radionuclides in ALPS Treated Water
(Reference2) ALPS treated water
ALPS treated water is water which is processed by devices such as ALPS (Advanced Liquid Processing System) to ensure that the concentration of radioactive materials other than tritium surely meets the regulatory standards for safety. In addition, the ALPS treated water is sufficiently diluted before the discharge into the sea so that the concentration of radioactive materials, including tritium, is far below the regulatory standards for safety.
(Reference3) Interlaboratory Comparison (ILC)
In the ILC, the IAEA, third country analytical laboratories selected by the IAEA, and Japanese laboratories analyze the same samples collected individually, and the IAEA compares their analysis results to confirm that the laboratories’ analytical methods and analysis results for radionuclides are appropriate.
(Reference4) Measurement/confirmation tanks
The tanks used to receive ALPS treated water from the storage tanks etc. on the premises of TEPCO’s FDNPS, and to circulate and stir ALPS treated water to collect representative samples for the analysis prior to the dilution and discharge.