The Demon Core

Following the bombing of Hiroshima and Nagasaki, there was no guarantee of a Japanese surrender. In the case that the Japanese refused to surrender to the Americans, the US planned for more nuclear weapons to be dropped. One part of one of these bombs that could have been dropped in this event, was a plutonium core, initially named Rufus. However, only two bombs were dropped and the core was never utilized. The core was, however, not simply thrown away and was still used in research. This would result, however, in the death of two Manhattan Project physicists, Louis Slotin and Harry Daghlian on two separate occasions, leading to it's name change, now called the demon core.

In the first tragic incident occured on August 21, 1945. Daghlian when attempting to build a neutron reflector around the core he accidentally dropped a brick on the core leading to a criticality accident, or an uncontrolled nuclear fission reaction. Despite the extensive treatment he was given after the incident, his exposure which caused severe radiation poisoning would ultimately kill him 25 days after the accident. 

The second incident would occur on May 21, 1946. While Slotin was showing his colleagues how to bring an exposed nuclear core to the point just before criticality. In this process he used a screwdriver as a wedge to slowly lower the tamper, a half-shell of beryllium that would reflect the neutrons shooting off the plutonium. This process would jump start a very small and weak nuclear reaction that scientists could collect data on. Unfortunately, the screwdriver slipped, the tamper dropping fully over the core. As a result, a significant burst of radiation fired into the room of scientists, leading to the eventual death of Louis Slotin. The hand touching the core reportedly developed a waxy blue appearance and developed large blisters. He developed further symptoms of nausea and abdominal pain, internal radiation burns, his lips turned blue, and eventually, he fell into a coma. Nine days following the experiment he would die.

These incredibly morbid instances of tragedy during the creation and development of atomic weapons highlights how dangerous they are. Not only were they dangerous for the potential enemy or enemies, but also for the producers of the weapons as well. Fortunately, the aftermath of accidents such as this and the end of the Second World War would lead to better safety regulations and steadier pacing for development of such technologies to keep such tragedies from happening again.

Source:
https://www.newyorker.com/tech/annals-of-technology/demon-core-the-strange-death-of-louis-slotin
https://www.atomicheritage.org/profile/harry-daghlian