by Brian Merchant, Brooklyn, New York on 01.27.10

eats radioactive waste

Photo via Science Daily

// Nuclear waste is probably the most dreaded substances in existence, in part because it’s proved so difficult to effectively clean up and store. But a stunning new breakthrough has just surfaced that may make cleaning up radioactive waste easier and much more efficient–and the solution takes its inspiration from one of everyone’s favorite creepy plants. Researchers have developed a material that opens its pores to let in its intended prey–the radioactive ion cesium–then “snaps shut” to entrap it, according to Science Daily. It’s a Venus Flytrap that eats radioactive waste instead of flies.

The flytrap-like material is evidently a snythetic material made from “layers of a gallium, sulfur and antimony compound,” and was developed by researchers at Northwestern University.

The radioactive ion cesium, found in nuclear waste, is very difficult to clean up. And that’s because the ratio of harmless sodium ions to dangerous radioactive cesium ions is 1,000 to 1. There’s tons more sodium than cesium–one scientist on the project even said that looking for the radioactive material in nuclear waste is “like looking for a needle in a haystack.” But the material the scientists developed turned out to be extremely adept at removing the cesium from a sodium-heavy solution–thanks to its Venus flytrap-like qualities.

SD explains:

It is, in fact, cesium itself that triggers a structural change in the material, causing it to snap shut its pores, or windows, and trap the cesium ions within. The material sequesters 100 percent of the cesium ions from the solution while at the same time ignoring all the sodium ions.

Which is pretty amazing–a material that can selectively snag and confine only the radioactive ions in nuclear waste could be instrumental in nuclear waste cleanup. Especially since there are over a hundred nuclear power plants across the US keeping their radioactive waste in storage onsite.

excessive radioactivity

One of the most fascinating things about the discovery is how it can trap literally every single radioactive cesium ion without bothering to absorb any sodium ions–sort of like how a Venus Flytrap doesn’t bother with drops of rain or debris that falls into its ‘mouth’ and attacks only the flies. Again, SD explains how this works:

The snap-shut Venus flytrap mechanism occurs because ‘soft’ materials like to interact with each other. A cesium ion is big and soft, and the metal-sulfide material is soft, too. The cesium ions are attracted to the material, specifically the sulfur atoms, and together form a weak bond. This interaction causes the material to change shape, close its windows and trap the cesium — like a juicy insect in a flytrap. Sodium, which is clothed in water molecules, can’t trigger the response.

It will certainly be interesting to see how this develops, and if this can successfully be transformed into a major new way to cleanup nuclear waste.


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