TEPCO announces discharge of ALPS treated water into sea.

Tokyo Electric Power Company Holdings (TEPCO) has initiated the release of multi-nuclide removal equipment treated water into the sea as part of the Fukushima Daiichi Nuclear Power Plant decommissioning process.

The Fukushima Daiichi Nuclear Power Plant in Japan is set to release 5 trillion Bq over the 2023 fiscal year. The water contains tritium, a radioactive isotope of hydrogen, and will be diluted to 740 times the legal limit before being discharged. The release has been met with opposition from local fishermen and environmental groups, who argue that it will harm marine life and damage the reputation of the region’s seafood industry.

TEPCO has released a report detailing the decommissioning process, within which they disclose that the discharge facility is comprised of three sets of tank groups, each with the role of receiving, measurement/confirmation, and discharge.

The Advanced Liquid Processing System (ALPS) treated water, following re-purification, is discharged through a discharge tunnel. The concentrations of each radioactive substance are measured and confirmed to ensure that only water with legally required concentrations of radioactive substances is discharged, and emergency isolation valves will automatically close in case of abnormal radiation levels or equipment malfunction at the Fukushima Daiichi Nuclear Power Plant.

The report outlines that TEPCO plans to discharge ALPS treated water into the sea in two stages. The first stage involves verifying the tritium concentration in a small amount of water, while the second stage involves continuous discharge to verify facility integrity and operational procedures.

During the initial stage of discharge, stored water that does not require secondary treatment will be discharged.

TEPCO asserts that they plan to disclose real-time data on the discharge of ALPS treated water on their website, the data will include the status of facilities related to the discharge, analysis results for treated water, and real-time data on seawater and treated water flow. The data will be updated every hour, with data for the intake/vertical shaft monitor updated every 10 minutes. The disclosure is planned to coincide with the commencement of the second stage.

TEPCO plans to continue providing tours to residents of Fukushima prefecture to see the decommissioning site and address concerns. They have also established a new observation platform on site at the Fukushima Daiichi nuclear power station to enhance understanding of their opertaions.

TEPCO’s report indicates that they have been using different media platforms to ensure transparent communication about the decommissioning process. These include newspaper ads, radio broadcasts, a dedicated treated water portal site, pamphlets, and YouTube videos educating viewers on the properties and management of ALPS treated water.

To demonstrate that ALPS treated water is safe, marine organisms are being reared in two different seawater environments:  with and without ALPS treated water. Results so far have shown that tritium concentration in the creatures’ bodies does not exceed that of the rearing environment, and concentrations decrease when returned to normal seawater.

Following two years of research by an International Atomic Energy Agency (IAEA) Task Force, the Agency released a report on July 4, 2023 confirming that the discharge of ALPS treated water will have a negligible radiological impact and is consistent with international safety standards.

“Based on its comprehensive assessment, the IAEA has concluded that the approach and activities to the discharge of ALPS treated water taken by Japan are consistent with relevant international safety standards,” IAEA Director General Rafael Mariano Grossi said in a foreword of the report.

Closing words in TEPCO’s report assert that it will continue to review and disseminate information objectively and transparently.