California scientists are warning that still-radioactive wreckage from the destroyed nuclear plant at Fukushima, Japan, could wash up on their state's shores. There are four things to understand here.
First, the physical debris from the nuclear disaster at Fukushima was radiated with iodine 131, which has a half-life of eight days and will be gone within about three months; and with cesium 137, which has a half-life of 30 years and is thought to increase rates of cancer.
Second, much of the radiated debris from Fukushima washed into the Pacific Ocean.
Third, there is an entire field of scientific research that focuses entirely on how debris moves, over months and years and centuries, within ocean currents. It's an esoteric field, but also a complicated one, taking into account all sorts of meteorological and geological systems we still don't quite understand.
And, fourth, ocean currents have slowly gathered decades of small and large trash from across the Pacific rim -- which includes many of the world's most populous nations -- into something called the "Great Pacific Garbage Patch," which also collects many of the thousands of shipping containers that fall into the ocean every year. Despite years of research, we still have an imperfect understanding of how the garbage patch works, how things get there, and what makes them leave.
So it's not guaranteed that radioactive Fukushima waste will show up at, say, Port Angeles. But when Seattle-based oceanographer Curt Ebbesmeyer told the northern California Times-Standard that debris was likely to hit the coast within two the three years -- when it will still be radioactive -- he wasn't just guessing. After half a century of studying the paths of Pacific flotsam, and the Great Pacific Garbage Patch, he knows what he's talking about. But, he added, weather is unpredictable, and "We know very little about the ocean."
The chance that Oregon beachcombers could one day stumble upon a radioactive girder or piece of concrete, however remote, underscores the risks inherent in nuclear energy. At this point, however, there's not much to do except buy stronger sunscreen.