Press Releases
Publication of the Results for the IAEA’s Interlaboratory Comparison on the Determination of Radionuclides in ALPS Treated Water
On October 5, 2026, the IAEA published a report of the results of 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, France, the Republic of Korea, and Switzerland selected by the IAEA on ALPS treated water taken from measurement/confirmation tanks in July 2025 and released its results.
- This is the fourth publication of the report since the first ILC report on ALPS treated water was published in May 2023.
- 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 Fukushima Daiichi Nuclear Power Station (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 forth Interlaboratory Comparison on the Determination of Radionuclides in ALPS Treated Water (PDF)
- Publication of the Results for the IAEA’s Interlaboratory Comparison on the Determination of Radionuclides in the Marine Environment
- 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 that contained radioactive substances from inside the buildings of TEPCO’s FDNPS, and has been purified and treated through multiple treatment facilities, including ALPS (Advanced Liquid Processing System), until the concentrations of all radioactive substances besides tritium ensure to satisfy the safety regulatory standards. As for tritium, the water is significantly diluted with seawater before the discharge into the sea so that it fully satisfies safety regulatory standards.
(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.