Opening Fukushima floodgates: Modelling 137Cs impact in marine biota

A numerical model was applied to simulate the transport of 137Cs released with the waters which were used to cool Fukushima reactors. These stored waters will be released to the Pacific Ocean according to Japanese government plans. The radionuclide transport model is Lagrangian and includes radionuclide interactions with sediments and an integrated dynamic foodweb model for biota uptake. Calculations made from a conservative approach indicate that expected concentrations in sediments and marine fish would be orders of magnitude below those detected after Fukushima accident and also lower than those resulting from global fallout background. •Model applied to simulate 137Cs transport in the Pacific Ocean from planned Fukushima releases.•The Lagrangian model includes interactions between water and sediments.•Dynamic foodweb model for radionuclide biota uptake integrated within the transport model.•Resulting concentrations in sediment and biota are below background levels.