The Dangers of Radiation Exposure

Radiation poisoning is one of the most devastating and horrific forms of death.

The Demon Core: Origins and Specifications

The Demon Core was a subcritical spherical mass weighing 6.2 kilograms, created during World War II as part of a third atomic bomb intended for Japan, stemming from the Manhattan Project. After Japan’s surrender, it was retained for further examination at the Los Alamos Laboratory.

The Experimentation Process

Physicists studied the core's criticality limits through a method that many referred to as “tickling the dragon’s tail.”

When handling a mass of plutonium situated just below the criticality threshold, meticulous care was paramount. Plutonium periodically emits neutrons, and if the surrounding environment becomes sufficiently enclosed, an increasing number of neutrons can be reflected back to the plutonium. This interaction can destabilize the nuclei of the plutonium atoms, leading to a chain reaction that releases energy and additional neutrons—essentially a nuclear fission reaction.

When the environment around the core is enclosed enough to reflect neutrons, it can trigger a sustainable fission reaction, resulting in a criticality accident. This occurrence signals that the core has crossed the criticality threshold, transitioning from stability to fission. The consequences include the sudden release of lethal neutron and gamma radiation.

To test the limits, physicists constructed a brick wall around the core, partially covering it with a lid. Both the wall and lid acted as neutron reflectors, with a common screwdriver being the only barrier between the lid and the core.

Tragic Outcomes

The first casualty was Harry Daghlian, who was conducting the experiment alone while a security guard observed from a distance. As he built the brick wall, one of the bricks fell onto the core, instantly triggering a supercritical state. A blue light, indicative of Cherenkov radiation, illuminated the room, signaling that the situation had spiraled out of control. Daghlian quickly removed the brick and halted the chain reaction, but his fate was already sealed. He succumbed to acute radiation poisoning 25 days later. The security guard, Robert Hemmerly, would later die from leukemia 33 years afterward.

The second incident involved Louis Slotin, who was also working with the same plutonium core.

Slotin was set to leave Los Alamos and was demonstrating the experiment for his successor, Alvin Graves. Although safety shims were supposed to be used, Slotin opted to rely solely on the screwdriver to keep the lid from closing completely. Unfortunately, he lost grip of the screwdriver, allowing the lid to close fully for a brief moment. The dreaded blue light appeared immediately, and Slotin was exposed to a massive dose of neutron and gamma radiation as the core became supercritical. He swiftly removed the lid but was acutely aware of his grim fate, uttering, “Well, that does it.” He passed away nine days later from acute radiation poisoning. Graves, positioned behind Slotin, received a high radiation dose as well, but Slotin’s body shielded him from the worst effects, allowing him to survive.

In the aftermath, the infamous Demon Core was ultimately melted down and repurposed to create other cores. While these tragic deaths were horrific, they contributed to heightened awareness and stricter security measures in handling radioactive materials. The ionizing radiation produced by such materials poses a severe threat to human health, often leading to excruciating and protracted deaths.