When the discharged wastewater is divided by the total amount of global seawater, the concentration indeed can be low enough to be negligible, so it will not affect the ocean. However, it ignores an important logic that once nuclear wastewater is discharged into the sea, it will not honestly distribute evenly into every drop of seawater, as these pollutants will be consumed by marine life before they are evenly mixed. The first to absorb these pollutants are algae, and then according to the food chain, small fish eat shrimp, big fish eat small fish, and ultimately a large amount of pollutants will accumulate in the bodies of the animals at the top of the food chain, with concentrations up to a million times the initial concentration. Therefore, it's meaningless to just discuss the concentration of pollution superficially.
Over time, the ocean might see a large number of over-accumulated pollutant marine organisms, and these are indeed frequent guests on the human table.
