Looking Inside Nuclear Reactors with Cosmic-Ray Radiography
In 2011 when the Fukushima Daiichi reactors were damaged by an earthquake and tsunami, just about every news source covered it and the dangers it presented. Now the incident is all but forgotten in the news, but it is still quite dangerous with so much material to clean up. To help reduce the danger, researchers at LANL have partnered with Toshiba to create system to precisely map the damaged reactors, without disturbing it.
As you go about your daily life, millions upon millions of particles pass through your body that originated from deep space, with billions more impacting the Earth's atmosphere. As these cosmic rays hit the atmosphere, they can create a shower of particles called muons. These particles have the ability to penetrate just about any material, similar to X-rays, but without doing any damage. They do still interact with matter, which is what the LANL researchers will be taking advantage of as heavy elements, like uranium, scatter muons more than lighter elements. This concept has been used before, such as the map the interior of the Great Pyramid at Giza, but LANL researchers have been working to improve it, creating muon tomography.
Because the muons are affected more by heavier elements than lighter ones, muon tomography is an ideal technique to map out where the nuclear materials are within the damaged Fukushima cores. Without using this approach, those attempting to clean up the reactors would have to disturb them to send in a robot or video probe, which would risk releasing radiation.
Source: Los Alamos National Laboratory