August 27, 2023

The Japanese Government announced that it had made a decision in regards to the commencement period of the discharge of water treated with multi-nuclide removal equipment (ALPS treated water) into the sea and asked that TEPCO begin preparations for the commencement of discharge. As the entity responsible for the safe and steady decommissioning of the Fukushima Daiichi Nuclear Power Station, TEPCO is strictly abiding by the Government’s decision and request, and shall quickly make preparations to commence discharge with the utmost vigilance in accordance with the implementation plan.
Since the accident, over 1.3 million tons of nuclear wastewater have been collected, treated, and stored in a tank farm at the plant. That storage space is about to run out, the Japanese government says, leaving no choice other than to begin dispensing the wastewater into the Pacific.
During the initial stages of sea discharge, a very small amount will be carefully discharged using a two-step process.
There’s a radioactive isotope that Tepco cannot filter out: tritium. Tritium is an isotope of hydrogen, and hydrogen is part of the water itself (H20). So it is impossible to create a filter that could remove the tritium.
Firstly, as Stage 1 of the initial discharge of ALPS treated water, a very small amount of ALPS treated water will be diluted with seawater and stored in the vertical discharge shaft (upstream water tank) in order to verify that ALPS treated water is being diluted as planned. After this stored water has been sampled and tritium concentrations measured, Tepco will move on to Stage 2, continuous discharge into the sea on and after August 24.
Japan’s discharge plan involves incrementally releasing it over the next three decades, although some experts say it could take longer, given the amount still being produced.
(Source: TEPCO – Image: Fukushima contaminated water storage tanks/American Nuclear Society)