Within days of the 2011 Fukushima nuclear plant disaster, radiation could be detected in the atmosphere all the way from the America’s West Coast. But the plume of radionuclides, including Cesium-137, that was released into the Pacific Ocean is still spreading and dispersing, and will likely reach Hawaii and the northwestern American coastline next year.
The good news—the silver lining to the plume—is that even though there will be a “measurable increase in radioactive materials,” the concentration of those materials will be well below World Health Organization safety levels by that point.
That's according to a study from the Centre of Excellence for Climate System Science, a mostly Australian research organization, which mapped the radioactive plume’s path through the world’s ocean for the next ten years. According to the report, “two energetic currents off the Japanese coast—the Kuroshio Current and the Kurushio Extension—are primarily responsible for accelerating the dilution of the radioactive material, taking it well below WHO safety levels within four months [of the incident].” Other eddies and whirlpools will continue the dilution process and direct the radioactive particles disparately westward, the study states.
For the rest of the story: http://motherboard.vice.com/blog/expect-fukushimas-radioactive-ocean-plume-to-hit-the-us-next-year