Press Release

August 27, 2023
  • Water & Soil

Results of ALPS Treated Water Marine Monitoring (Sampling on August 25, 2023)

1. The Ministry of the Environment (MOE), Japan has been conducting marine monitoring related to ALPS treated water that started to be discharged in the afternoon of August 24, 2023.
2. The analysis results of seawater, sampled in the morning of August 25 showed that the tritium concentrations were below the lower limit of detection (below 7~8 Bq/L) at all 11 sampling points and would have no adverse impact on human health and the environment.
3. In this analysis, the concentrations of Gamma (γ) ray nuclides were also measured and found to be below the lower limit of detection for all of the samples.

■ Outline of the monitoring

MOE Japan is to conduct weekly analysis of tritium concentrations for the purpose of rapid analysis, together with γ ray nuclides (Cesium-137 and other nuclides), for the time being, to strengthen and expand monitoring after discharge of ALPS treated water. This press release announces the first monitoring results.

■ Details of the monitoring results

Details of the monitoring results are available in the Attachment below and on the website of “ALPS Treated Water Marine Monitoring Information” (
The results of the subsequent monitoring will be uploaded on the same website.

■ Sampling of seawater


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