A dramatic portrait-oriented movie poster featuring only the title at the top. The image shows a small, metallic plutonium sphere glowing with a blue light, set against a dark, ominous Los Alamos laboratory backdrop.

The demon core was a small, 6.2‐kilogram plutonium sphere measuring about 3.5 inches in diameter and was created during the Manhattan Project.

Demon core - Wikipedia

A large oval-shaped structure

Originally intended for a third atomic bomb that was never deployed after Japan surrendered, this core was retained at Los Alamos for criticality experiments.

Expanding explosion from an atomic bomb test, New Mexico

During its experiments, minor mishaps caused the core to go supercritical, releasing lethal blue flashes of neutron radiation and tragically claiming the lives of two scientists.

These fatal incidents led to the implementation of remote-handling techniques and strict safety protocols, forever changing nuclear experimentation.

M3000 Manipulator System

Most labs have dedicated waste containers for sharps, biohazardous waste, radioactive waste, and organic chemicals.

Student working with computer and other research technology

Illustration of pensive and distraught workers standing in a hallway

The Demon Core: A Deadly Slice of Nuclear History

The demon core was a small, 6.2‐kilogram plutonium sphere measuring about 3.5 inches in diameter and was created during the Manhattan Project.
Originally intended for a third atomic bomb that was never deployed after Japan surrendered, this core was retained at Los Alamos for criticality experiments.
During its experiments, minor mishaps caused the core to go supercritical, releasing lethal blue flashes of neutron radiation and tragically claiming the lives of two scientists.
These fatal incidents led to the implementation of remote-handling techniques and strict safety protocols, forever changing nuclear experimentation.

The Demon Core: A Deadly Slice of Nuclear History

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