Researchers use cosmic rays to assess damaged reactor cores

In a paper in Physical Review Letters, researchers compared two methods for using cosmic-ray radiography to gather images of nuclear material within the core of a reactor similar to Fukushima Daiichi Reactor No. 1.

The team reportedly found that Los Alamos’s scattering method for cosmic-ray radiography was better than the traditional transmission method for capturing high-resolution image data of potentially damaged nuclear material.

‘Within weeks of the disastrous 2011 tsunami, Los Alamos’s Muon Radiography Team began investigating the use of Los Alamos’s muon scattering method to determine whether it could be used to image the location of nuclear materials within the damaged reactors,’ said Konstantin Borozdin of Los Alamos’s Subatomic Physics Group and lead author of the paper. ‘As people may recall from previous nuclear reactor accidents, being able to effectively locate damaged portions of a reactor core is a key to effective, efficient clean-up.’

According to LANL, muon radiography (also known as cosmic-ray radiography) uses secondary particles generated when cosmic rays collide with upper regions of Earth’s atmosphere to create images of the objects that the particles — muons — penetrate. The process is said to be analogous to an X-ray image, except muons are produced naturally and do not damage the materials they contact.