The problem of nuclear waste, particularly from nuclear reactors, is a big one, given that it is the one stalling point that prevents environmentalists from wholly supporting nuclear power over dirtier power sources such as oil and coal. The opposition to building a nuclear waste site in Arizona in the last decade was significant, not least of which because of the lethal health risks of those near the waste site, and those near the rails that carried the nuclear waste to the site. The quandary of reducing and destroying it so that it is more manageable remained elusive. But now, scientists and engineers in England discovered a method of turning nuclear waste to glass, destroying and stabilizing the material so that it can be managed properly. The method? Blast furnace slag, a polluting form of metal.
Blast furnace slag is a byproduct of smelting metal ore, which is used to purify iron and create steel. In the case of blast furnace slag, it is often used to make concrete, especially more durable and lighter-colored concrete made with Portland cement. However, while the slag itself is not toxic or polluting, the process of smelting the ore can result in the creation of fly ash, a known pollutant.
The researchers at the University of Sheffield's Faculty of Engineering spearheaded the effort, which they are doing as part of their efforts to investigate nuclear waste. Using the less radioactive but similarly functioning cerium as a replacement for plutonium, scientists mixed the substitute waste and blast furnace slag together, then heated them under pressure to form glass, a process called vitrification.
When they material turned into glass, the researchers discovered that the glassed waste lost approximately 85-95% of its overall volume. Furthermore, the resulting material was stable, and thus far more resistant to corrosion. This makes the material far safer and less expensive to store overall. That the process requires only one common item makes it even cheaper.
The University of Sheffield team, led by Professor Neil Hyatt, would like to optimize the project, so as to make it a viable venture and prove it works on real plutonium. It will likely be used to clean up accidents such as those in Fukushima, which remains in a precarious situation following clean up attempt, as well as shutting down old nuclear power plants.