An X-Ray Machine for Nukes

The government is upgrading the X-ray technology that detects flaws in its nuclear weapons stockpile.

The new machine, called the Confined Large Optical Scintillator Screen and Imaging System, or CoLOSSIS, uses thousands of 2D X-ray images to produce one 3D image depicting the inside of a nuclear weapon — the same way CT scanners generate 3D images of the inside of a human body. Developers say the new system will pick up more defects in the nuclear stockpile than the current 2D sensors and will eliminate the need to disassemble weapons to search for problems, which is a process that can be destructive.

The Energy Department’s National Nuclear Security Administration teamed up with scientists from the Lawrence Livermore National Laboratory, in Livermore, Calif., and the Pantex Plant, near Amarillo, Texas, to build the system. “Anything that’s changing, we’ll detect that change in the weapon’s density structure,” says Randall Hodges, a department manager in Pantex’s non-destructive evaluation and manufacturing division. “You couldn’t gather this data before without cutting things and destroying things.”

The machine is an 11.5-foot-long box that is packed with cameras, lenses and lead shielding to protect the equipment from the radiation used to produce the images. It can take up to 72 hours to scan a single weapon, and officials then have to send the data to laboratories in Los Alamos, N.M., or Livermore, where scientists compile the information into 3D images, Hodges says.

At that point, scientists examine the images for defects, which in most cases would not affect the performance of the weapon, Hodges adds. The NNSA has already started testing weapons using the new tool.

It allows officials “to pick out the most pristine weapons to remain in the nuclear stockpile,”