Japan Starts First Discharge of Contaminated Water... 7,800 Tons to Be Released Over Next 17 Days (Comprehensive)

Release into the ocean begins at 1:03 PM... Tritium concentration below standard
First discharge in 12 years since the Great East Japan Earthquake... Concerns remain

Japan began releasing contaminated water from the Fukushima Daiichi Nuclear Power Plant into the ocean on the 24th. This marks the start of discharge 12 years after the Great East Japan Earthquake in March 2011. The initial release will continue for 17 days, with approximately 7,800 tons of contaminated water expected to be discharged into the ocean.

NHK reported that Tokyo Electric Power Company (TEPCO) started releasing contaminated water into the ocean at 1:03 p.m. that day. TEPCO declared the start of discharge after determining that the tritium concentration in the contaminated water was below the standard level and that weather conditions were suitable for deploying monitoring vessels.

[Image source=Yonhap News]

7,800 Tons to be Released Over 17 Days... Tritium Concentration Below Standard

On the 22nd, TEPCO sent about 1 ton of contaminated water to a dilution facility for the discharge process, mixed it with seawater, and collected it in a large tank to check the tritium concentration.

TEPCO announced that the analysis showed a concentration of 43 to 63 becquerels (Bq) per liter (ℓ), which is significantly below the national standard of 60,000 Bq. It also falls below the discharge standard of 1,500 Bq, leading TEPCO to state that "the contaminated water is being diluted without issues."

The discharge will continue for 17 days, with TEPCO diluting about 460 tons of contaminated water daily with seawater before releasing it into the ocean. The initial amount of contaminated water to be discharged is approximately 7,800 tons.

TEPCO plans to repeat this process four more times, with the total discharge volume for this year expected to reach 31,200 tons, equivalent to 30 contaminated water tanks.

Currently, contaminated water is stored in about 1,000 tanks on the Fukushima Daiichi Nuclear Power Plant site, with 1.34 million tons filling 98% of the tank capacity.

[Image source=Yonhap News]

How the Discharge Process Works... Mixing with Seawater and Releasing via Undersea Tunnel

The contaminated water stored in tanks has first undergone treatment by the Advanced Liquid Processing System (ALPS). ALPS removes 62 types of radioactive materials, including cesium. However, tritium and trace amounts of carbon-14 remain untreated.

TEPCO plans to dilute this water with seawater to reduce the concentration to below 1,500 Bq, which is one-fortieth of Japan’s regulatory standard, before releasing it into the ocean. They emphasize that this level corresponds to one-seventh of the World Health Organization (WHO) drinking water standard.

The discharge process begins with operators in the plant’s central monitoring room activating pumps. The pumps mix ALPS-treated contaminated water with seawater and continuously flow it into a large tank. Overflow from this tank flows through an undersea tunnel leading to a discharge outlet located 1 km offshore, releasing the water into the ocean.

The sea in front of Fukushima Prefecture where the discharge has begun. (Photo by ANN News)

Discharge to Continue for 30 Years... Concerns Remain

Although the initial discharge has started, concerns persist both inside and outside Japan. The Japanese government plans to continue releasing contaminated water for 30 years before moving to decommissioning, but melted nuclear fuel remains inside the accident site, with rainwater and seawater flowing in. NHK reported that "the inability to eliminate the cause of increasing contaminated water and the impossibility of releasing large volumes at once are problematic," adding that "ensuring safety over the long term will be a critical challenge."

China, Hong Kong, and South Korea have imposed import restrictions on Japanese food products, posing new concerns for Japan. Above all, the blockage of export routes to China due to this discharge is expected to deal a blow to the Japanese economy. NHK stated, "Japan’s exports of agricultural, forestry, fishery products, and food to China reached 278.3 billion yen last year. Since China was Japan’s largest export market, the impact is expected to expand."

[Image source=AFP Yonhap News]

The International Atomic Energy Agency (IAEA), which verified the Fukushima contaminated water discharge process, reiterated the importance of transparent monitoring. In a statement issued under the name of Director General Rafael Grossi, the IAEA announced, "IAEA experts have confirmed that TEPCO has started discharging ALPS-treated water."

They added, "IAEA experts are on-site to oversee the discharge process on behalf of the international community, ensuring it proceeds as planned. Our presence on-site contributes to the discharge being conducted safely and transparently."

This content was produced with the assistance of AI translation services.