World War II – October 2019

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NAZIS

CLOSER

THAN THEY

KNEW TO

NUCLEAR

REACTOR

DEEMING THE FOCUS of their discovery

“a failure worth celebrating,” two aca-

demic researchers learned that the Nazis

bungled their nuclear weapons program

and missed a chance to develop a reactor

during World War II.

A winding trail of evidence led to the

realization that the Germans had indeed

possessed enough uranium cubes to build

a working reactor—but failed to recognize

it because their scientists were divided

into three teams working separately and

in competition with each other.

The detective work started in the

summer of 2013 when a five-pound ura-

nium cube measuring two inches per side

found its way to physicist Timothy Koeth,

director of the University of Maryland’s

nuclear reactor and radiation facilities. It

came wrapped in brown paper towels and

accompanied by a mysterious note that

read: “Taken from the reactor that Hitler

tried to build. Gift of Ninninger.”

Koeth recognized the cube from grainy

photos in books on nuclear history. It was

one of 664 uranium cubes assembled by

renowned German physicist Werner

Heisenberg for a reactor hidden in a cave

beneath a castle in Haigerloch, Germany.

In an account of their research in Physics

Today in May, Koeth and doctoral student

Miriam Hiebert wrote that Heisenberg’s

team used aircraft cables to string the

cubes into an “ominous uranium chande-

lier” and submerged them in heavy water.

The “configuration was the best design the

German program had achieved thus far,

but it was not sufficient to achieve a self-

sustaining, critical reactor,” the two noted.

WWII TODAY

REPORTED AND WRITTEN BY PAUL WISEMAN

This 1940s German

uranium cube found

its way to an American

scientist in 2013.

10 WORLD WAR II