https://motherboard.vice.com/en_us/article/ywkd9x/two-government-employees-had-weapons-grade-plutonium-stolen-from-their-rental-car

An unknown amount of weapons-grade plutonium, a critical ingredient in the manufacture of nuclear warheads, was stolen from the backseat of a car rented by a US Department of Energy employee—and more than a year later, we’re only finding out about it.

On March 21, 2017, two security experts from the Department of Energy’s Idaho National Laboratory drove to San Antonio, Texas, to retrieve radioactive materials from a nonprofit research lab. The recovery mission was part of the National Nuclear Security Agency’s Off-Site Source Recovery Program, which hunts down small samples of fissile material that have been distributed to various public and private research facilities prior to the late 90s. It is harder to keep track of fissile material when it is distributed at hundreds of different sites, so the recovery program aims to reduce the risk of the material falling into the wrong hands by consolidating it at national laboratories.