A tale of lost WW2 uranium cubes shows why Germany’s nuclear program failed

Enlarge / This is one of the 664 uranium cubes from the failed nuclear reactor that German scientists tried to build in Haigerloch during World War II. (credit: John T. Consoli/University of Maryland)

When University of Maryland physicist Timothy Koeth received a mysterious heavy metal cube from a friend as a birthday gift several years ago, he instantly recognized it as one of the uranium cubes used by German scientists during World War II in their unsuccessful attempt to build a working nuclear reactor. Had there been any doubt, there was an accompanying note on a piece of paper wrapped around the cube: "Taken from Germany, from the nuclear reactor Hitler tried to build. Gift of Ninninger."

Thus began Koeth's six-year quest to track down the cube's origins, as well as several other similar cubes that had somehow found their way across the Atlantic. Koeth and his partner in the quest, graduate student Miriam "Mimi" Hiebert, reported on their progress to date in the May issue of Physics Today. It's quite the tale, replete with top-secret scientific intrigue, a secret Allied mission, and even black market dealers keen to hold the US hostage over uranium cubes in their possession. Small wonder Hollywood has expressed interest in adapting the story for the screen.

Until quite recently, Koeth ran the nuclear reactor program at UMD, which is how he met his co-author. Hiebert is completing a PhD in materials science and engineering, specializing in the study of historical materials in museum collections (glass in particular) and the methods used to preserve them, using the reactor facility for neutron imaging of a few samples. Koeth told her about his research into his cube's origins, and she started collaborating with him as a side project.