Wednesday, September 19, 2007

New Lasers Make Radioactive Waste Safe


Radioactive waste is only a problem when it remains radioactive for vast amounts of time. Unfortunately, many of the byproducts of nuclear fission have half-lives of millions of years. Right now, we have no idea what to do with this stuff. It's hard to imagine next century, let alone 15 million years from now. Do we really want to leave this stuff lying around? It will almost certainly escape from anywhere we put it.

Luckily, scientists are working on ways to avoid these long-term problems. British scientists have "transmuted" iodine-129 into iodine-128 with a high-powered laser. Now, dropping one neutron might not seem like a big deal, but the half-life of iodine-129 is 15 million years while the half-life of iodine 128 is 25 minutes.

They've done it by focusing a high-powered laser on a pellet of gold for an extremely brief amount of time. The gold ionizes, becomes plasma, and emits gamma rays. The gamma rays then smash into the iodine, forcing out a neutron and making the material safe.

Now, scientists just have to figure out how to scale the process up to levels necessary in disposing of nuclear wastes, while keeping costs lower than the planned facility at Yucca Mountain. I wish them luck.


No comments: