TEPCO to Launch 6th Phase of Discharging ALPS Treated Water from FDNPS on May 17

Tokyo Electric Power Company (TEPCO) is set to begin the sixth phase of discharging the ALPS treated water from the Fukushima Daiichi Nuclear Power Station (FDNPS) on May 17. 

This initiative is part of the ongoing efforts to address the aftermath of the Great East Japan Earthquake that occurred in March 2011. The discharge process is expected to take 19 days to complete.

According to a statement recently issued by the Embassy of Japan in Cairo, a pre-discharge analysis made public on May 15 confirmed that the ALPS treated water to be discharged in the sixth batch had met the regulatory standards for discharge. 

Prior to that, TEPCO released the ALPS treated water for five times from August 2023. Monitoring has been conducted before, during, and after the timing of each discharge. From a scientific standpoint, all of these discharges have been safely conducted.

These discharges have been also reviewed and monitored by the International Atomic Energy Agency (IAEA). The Task Force – comprised of the IAEA and international experts – visited facilities used for discharging the ALPS treated water at the FDNPS. On April 26, the IAEA announced that the Task Force confirmed the discharges were safely progressing in accordance with the Implementation Plan approved by Japan’s Nuclear Regulation Authority (NRA).

The fifth batch of discharge

TEPCO conducted the fifth batch of discharge from April 19 to May 7, 2024. Throughout the fifth batch, the concentration of nuclides, including tritium in the seawater, measured before, during, and after the discharge was far below the relevant standards, which indicates that the discharge was safe as planned.

The discharge of ALPS treated water into the sea was conducted after dilution with seawater. As a result of this dilution process, each tritium concentration detected during the fifth batch of discharge was less than 266 Bq/L, far below the safety standard (1,500 Bq/L) set by the Government of Japan, let alone, much lower than the WHO Standards for Drinking Water (10,000 Bq/L).

Furthermore, each tritium concentration detected during and after the discharge off the coast of Fukushima prefecture has been less than 29 Bq/L, far below the safety standard (700 Bq/L) set by the Government of Japan.

Additionally, regarding radionuclides other than tritium, "the sum of the ratios of the concentration of each radionuclide to the regulatory concentration" was 0.31, well below the regulatory standard of 1, before the discharge into the seawater.

Confirmation by the IAEA Task Force of the safety of discharge

During the mission from April 23 to 26, the Task Force – comprised of the IAEA and international experts – visited facilities used for discharging the ALPS-treated water at the FDNPS. 

On April 26, the IAEA announced that the Task Force confirmed the discharges were safely progressing in accordance with the Implementation Plan approved by Japan’s Nuclear Regulation Authority (NRA).

Sampling surveys on marine products

Japan has voluntarily conducted sampling surveys on marine products and has conducted a component analysis of fish caught off the coast of Fukushima prefecture (regardless of whether it is for export or domestic consumption) after the discharge of ALPS-treated water into the sea, and no tritium exceeding the detection limit has been detected.

ALPS (Advanced Liquid Processing System) removes most of radionuclides in the water to meet the regulatory standards for discharge, with the exception of tritium. Tritium cannot be removed by purification and remains in the treated water, so the ALPS treated water is diluted by seawater by 100 times or more so that the tritium concentration at the discharge outlet becomes less than 1,500 Bq/L.

The first batch was conducted from August 24 to September 11, the second batch was conducted from October 15 to October 23, and the third batch was conducted from November 2 to November 20, all in 2023. The fourth batch was conducted from February 28 to March 17, the fifth batch was conducted from April 19 to May 7, all in 2024.