Nuclear power is often offered as a climate friendly energy source, albeit not without some security risks. One of those risks – the half-life of spent nuclear fuel, or the amount of time until the waste is no longer radioactive, is of particular concern.  Spent nuclear fuel includes lots of radioactive elements that take a long, long time to become safe. Here’s a quick look at how long is long:

The half-life of Iodine-129 is 15.7 million years. To put this in context, fifteen million years ago was a full ten million years before the predecessor to humans, Australopithecus afarensis, appears in the archaeological record (read 10 million years before the opening scene of “2001 A Space Odyssey”). (more…)