An Operational Ocean Current Forecast Model System in Predicting the Discharge of Tritiated Water from Fukushima

Following the 2011 Fukushima nuclear accident, treated tritiated water began being discharged into the ocean in 2023. To monitor its dispersion, Taiwan established a forecasting system based on a three dimensional hydrodynamic model to predict the dispersion of the contaminated water. The model domain reaches longitude 180E to capture Kuroshio effects, with high-resolution unstructured grids near the outfall. A particle tracking and diffusion module estimates concentration changes, using data published by TEPCO. Model validation uses tide gauge, drifter, altimetry, and satellite SST data. The system supports daily forecasting of tritiated water transport in the Western North Pacific.