The “Demon Core” was a sphere of plutonium-gallium alloy about the size of a softball, but its unassuming appearance belied its lethal potential. Designed for use in nuclear weapons during World War II, this core inadvertently became the centerpiece of two critical accidents in 1945 and 1946, which led to the deaths of two scientists. Here, we delve into the history, the accidents, and the profound implications of the Demon Core on nuclear safety standards.
The Birth of the Demon Core
The Demon Core was initially intended for use in a third nuclear bomb during World War II. However, with Japan’s surrender following the bombings of Hiroshima and Nagasaki, the core remained unused. It was repurposed for experimentation at Los Alamos National Laboratory, where scientists were eager to understand the parameters of nuclear fission—specifically, how much material was needed to achieve a self-sustaining nuclear chain reaction, known as criticality.
Tragic Miscalculations: The Accidents
The Demon Core’s notorious history is primarily marked by two criticality accidents involving physicists Harry Daghlian and Louis Slotin, which highlighted the dangers of handling radioactive materials.
- The Daghlian Accident (August 1945): While working alone one night, Harry Daghlian was constructing a neutron reflector experiment around the core. He accidentally dropped a tungsten carbide brick onto the assembly, causing the core to reach a supercritical state. Despite his quick reaction to disassemble the setup, he was severely irradiated and succumbed to acute radiation poisoning within a month.
- The Slotin Incident (May 1946): Less than a year after Daghlian’s death, another physicist, Louis Slotin, was demonstrating a criticality experiment known as “tickling the dragon’s tail.” Using a screwdriver to keep the two halves of a beryllium sphere separated, the tool slipped. The sphere closed around the core, initiating a prompt critical reaction and exposing Slotin and others in the room to a burst of neutron radiation. Slotin died nine days later from the effects.
Lessons Learned and Legacy
These tragic accidents served as a grim reminder of the risks associated with nuclear research. In response, safety protocols were drastically overhauled. Remote handling techniques, stringent safety regulations, and proper training became standard practice to prevent similar incidents.
The Demon Core itself was later melted down and reintegrated into the nuclear stockpile, but its legacy endures as a cautionary tale about the balance between scientific inquiry and the necessary respect for the forces it seeks to harness.
The story of the Demon Core is not just about the perils of nuclear physics but also about human fallibility in the face of potent and poorly understood technologies. It reminds us that with great power comes great responsibility, and safety must never be compromised in the quest for knowledge.