This article was taken from the June 2014 issue of Wired magazine. Be the first to read Wired's articles in print before they're posted online, and get your hands on loads of additional content by <span class="s1">subscribing online.
These rocky crevices are a warning sign of metals corroding within a nuclear reactor, because of exposure to a destructive stew of water, heat and oxidation. "Typically, one part corrodes first, and it changes the direction of the cracks," says Stephen Bruemmer, a materials scientist at the Pacific Northwest National Laboratory (PNNL) in Washington. Researchers are working to predict how cracks develop, and how metals might withstand pressure for longer.
Bruemmer's group simulates corrosions by placing iron- and nickel-based stainless steel samples in water heated to 360°C, triggering fractures. "We attempt to mimic the [reactor] conditions so that we can see how they affect the rate of cracking," says PNNL material scientist Matthew Olszta, who creates high-resolution images to pinpoint how the metal breaks. "Understanding the rate at which microscopic cracks initiate, propagate and blossom into macroscopic failures allows the nuclear industry to predict how to extend the lifetime of nuclear plants," says Olszta.
This article was originally published by WIRED UK
