❷ Measurement/Confirmation Facility Conditions

Measurement/Confirmation Facility Conditions

The measurement/confirmation facility is split into three groups of 10 tanks (Total capacity of 10 tanks: Approximately 10,000m3) with each of the groups used on a rotating basis as receiving tanks, measurement/confirmation tanks, and discharge tanks.

  • GroupAMeasuring/confirming

  • GroupBDischarge completed

  • GroupCMeasuring/confirming

ALPS treated water measurement results (June 26, 2024) 
⇒Confirmed that discharge criteria have been met.

The concentration of radioactive substances excluding tritium.

The sum of the ratios of the concentration of each radionuclide to the regulatory concentration: 

Regulatory standards
1

Analysis
results

The sum of the ratios of the concentration of each radionuclide to the regulatory concentration:
0.18

The concentration of radioactive substances excluding tritium.

The sum of the ratios of the concentration of each radionuclide to the regulatory concentration: 

Regulatory standards
1

*Nuclides that are voluntarily checked to ensure that they are not significantly present were confirmed not to be significantly present for all target nuclides.

Tritium concentration:17×104 Bq/L

Confirmed to be less than 1 million Bq/L

  • ※ALPS treated water with high tritium concentration is to be discharged at a later stage of the discharge period by considering the natural decay of radioactivity over time. This is indicated as the upper limit of 1 million Bq/L in the implementation plan (to be discharged starting from the water with lower tritium concentration)
  • ※Pre-dilution ratio of tritium concentration to the regulatory concentration limit(60,000Bq/L) is 2.83 , but the regulatory standard is met by diluting the tritium with large amount of seawater when discharging into the sea. (When diluted 740 times with seawater, ratio of tritium concentration to the regulatory concentration limit drops to 0.0038)

Measurement results from external agency designated by TEPCO (Kaken)

▶Tritium concentration: One hundred and seventy thousand Bq/L

▶The sum of the ratios of the concentration of each radionuclide to the regulatory concentration excluding tritium: 0.16