In Radiation Safety History
On August 23, 1991 workers at the Nuclear Research Centre, Karlsruhe,
discovered that an entire nuclear fuel assembly consisting of 37 fuel
rods had somehow been switched with a dummy (training) assembly.
During the course of finding the workers actually discovered instead
a further 48 kilograms of uranium is missing.
Although the plant has always passed regular fuel inventories made by
the IAEA, the loss was not detected because for 10 years inspectors
mistook a ‘dummy’ assembly made of 37 lead rods for a ‘live’ assembly
containing the missing uranium.