
Over the next few days, after the Kuroshio Current passes near the coast of Fukushima, Japan, it will continue to move northeastward and split into two branches, entering the waters east of Honshu, Japan, at 35.3°N and 38.3°N respectively. The maximum current speed in this area is approximately 1.2 m/s, and the current flows roughly northeastward, joining the extended Kuroshio Current, where the maximum current speed is approximately 1.8 m/s. This current then flows southeast and merges into the North Pacific Current. Along the Fukushima coast, it will move slowly northward, largely influenced by the north-south tidal movement and the Kuroshio Current.
In the seven-day forecast simulation, the discharged tritium-containing wastewater will be influenced by the Kuroshio Current and the North Pacific Current, spreading eastward. The primary affected area is the eastern waters of Honshu, Japan, where the maximum concentration reaches 1 x 10⁻⁴ Bq/L. The secondary affected area is the eastern part of the Kuroshio Current, where the maximum concentration reaches 1 x 10⁻⁵ Bq/L. Furthermore, the 10⁻⁷ Bq/L concentration line extends eastward to approximately 157.75 degrees west longitude and southward to approximately 21.0 ˚N latitude.
With emissions ceased, the recently discharged tritium-containing wastewater is primarily affected by the north-south tidal currents along the Fukushima coast, slowly spreading northward. The maximum concentration at a radius of 50 km from the discharge point reaches 5 x 10⁻⁴ Bq/L. Overall, based on the 10⁻⁷ Bq/L concentration threshold, the affected area covers approximately 5277 km east of the discharge point and approximately 3273 km north-south.
The 10-7 Bq/L concentration line is 1,302 km away from Taiwan Island and will have no impact on the waters surrounding Taiwan in the next 7 days.
