Last year, Tokyo Electric Power Co. released 60,000 tons of treated water from its damaged Fukushima 1 nuclear power plant.

And despite the presence of small amounts of radioactive tritium, it was said, no anomalies were detected in fish stocks in the Pacific Ocean.

August 24 marked the first anniversary of a 30-year program to release about one million tons of treated water into the sea.

The nuclear power plant experienced a triple meltdown following the earthquake and tsunami disaster in 2011.‘s cooling system.

The water used to cool the melted “fuel residue” mixes with rain and groundwater, which continues to penetrate the destroyed reactor buildings.

The amount of water contaminated with highly radioactive material continues to rise by about 80 tons per day.

With the exception of tritium, radioactive substances are filtered out using a process called Advanced Liquid Processing System (ALPS) and stored in large tanks on site.

In April 2021, when the number of tanks exceeded 1,000 and approached the plant‘Due to limited storage capacity on site, the government concluded that it had no choice but to discharge the treated water into the sea.

In August 2023, non-removable tritium-containing water diluted with seawater was released into the sea for the first time.

A total of about 60,000 tons have been unloaded since then.

But on August 1 of this year, about 1,312,000 tons remained.

The tanks that can now be dismantled due to the release only make up two percent of the total. TEPCO has stated that the site will be used to store leftover fuel after the tanks are dismantled.

TEPCO only discharges water that meets the national standard by diluting it with seawater to keep the tritium concentration below 1,500 becquerels per liter (1/40 of the national discharge standard).

The central government, together with TEPCO and other parties, has been closely monitoring the concentration of radioactive substances in seawater and fish around the power plant since emissions began. However, no abnormalities have been confirmed so far, TEPCO said.

According to the plans, all fuel elements are to be disposed of by 2051. This is the target year for the complete decommissioning of the power plant.

However, removing the fuel residues that have contaminated the contaminated water has proved extremely difficult. The first attempt to begin a test cleanup on August 22 was aborted due to a procedural error.

In addition to the release of the treated water, numerous other problems still need to be solved.

The amount of highly radioactive sludge produced during the treatment of contaminated water continues to increase, but there is still no effective treatment method.

The increasing amounts of sludge are stored in tanks, but since there is a risk of leakage even in liquid state, the plan is to dewater the sludge to reduce its volume and then process the substance into a solid.

In 2021, TEPCO submitted an application to build a plant for this purpose. However, the nuclear regulator pointed out the risk of radiation exposure to workers and asked TEPCO to review the design.

As a result, the start of the dehydration process was postponed from fiscal year 2022 to fiscal year 2026.

Furthermore, no concrete method for solidifying the dewatered slurry has yet been established.

TEPCO aims to determine the consolidation method by the end of fiscal year 2025 and start consolidation around fiscal year 2035.