Дэлхийн хоёрдугаар дайны төгсгөлд бүтээгдэж, туршилтын явцад хоёр ч удаагийн ослоор хүний аминд хүрсэн “Demon Core” буюу плутони голтын түүх цөмийн зэвсгийн аюул ослын томоохон сануулга болж үлджээ.
Манхаттэний төслийн хүрээнд Японд хаях зорилгоор бэлтгэсэн боловч дайн дууссаны улмаас ашиглагдаагүй үлдсэн уг плутони-галлийн голтыг Нью-Мексик муж дахь Лос-Аламосын лабораторид шинжлэх ухааны туршилтад ашиглаж эхэлсэн байна. Тус голтыг турших явцад критикийн байдалд шилжүүлсэн хоёр тусдаа ослын улмаас цацрагийн аюултай туяа ялгарч, АНУ-ын эрдэмтэд болон цэргийн алба хаагчид амь насаараа хохиржээ.
Анхны аюултай ослыг 1945 оны наймдугаар сарын 21-нд туршилт хийх үед доктор Харотун Даглиан гишүүн вольфрамын карбид тоосгоор голтыг хүрээлж байх явцад үүсгэжээ. Эцсийн тоосгыг байрлуулах үед хэмжигч хэт критикийн байдалд орсныг мэдсэн эрдэмтэн гараа татан авах зуураа уг тоосгыг туршилтын төв хэсэгт унагаж, гинжин урвал явагдан үхлийн аюултай цацрагийн туяанд өртсөн байна. Уг ослын улмаас доктор Даглиан 25 хоногийн дараа нас барсан бол ойр хавьд үүрэг гүйцэтгэж байсан байлдагч Роберт Хеммерли цацрагт өртөж, олон жилийн дараа цусны хорт хавдраар таалал төгсчээ.
Хоёр дахь ослыг 1946 оны тавдугаар сарын 21-нд доктор Луи Слотин болон бусад судлаачид бериллийн хагас бөмбөрцөг бүрхүүлийг угсрах явцад гар утасны халив мултарснаар плутони голт дахин критикийн байдалд орж хэт их хэмжээний цацраг ялгаруулжээ. Доктор Слотин биеэрээ хамгаалалт хийж хамтран зүтгэгчдээ аварсан хэдий ч өөрөө хурц цацрагийн хам шинж өвчнөөр хоёр долоо хоногийн дотор амь үрэгдсэн байна. Тус туршилтын өрөөнд байсан бусад найман хүн харилцан адилгүй хэмжээний цацрагийн хордлого авчээ.
Эдгээр цуврал эмгэнэлт ослын дараа “Demon Core” хэмээх нэр зүүсэн уг голтыг 1946 онд хайлуулж, дараа үеийн цөмийн зэвсгийн түлшинд ашиглахаар болсон юм. Хэдийгээр эдгээр туршилт нь хүний амь эрсэдсэн хүнд гарз хохирол авчирсан ч цацраг идэвхт бодис хүний биед хэрхэн нөлөөлдөг тухай шинжлэх ухааны мэдлэгийг тэлэхэд чухал хувь нэмэр оруулсан түүхтэй.
Дэлгэрэнгүйг эх сурвалжаас харах
Эх сурвалжийг нээх ↓
From jet engines to radar, World War II saw the development of all kinds of new technologies, but none were as impactful or as notorious as the atomic bomb. The Manhattan Project, headed by Dr. J. Robert Oppenheimer, produced the first nuclear bombs in 1945. The first used in combat was dropped on August 6, 1945, on Hiroshima, Japan. Three days later, a second bomb fell on Nagasaki, Japan, and on the following day, the Empire of Japan surrendered, though victory over Japan didn’t come until the United States officially accepted its unconditional surrender on September 2, 1945.
Had Japan not surrendered, the U.S. was prepared to drop a third bomb, which would have used a plutonium-gallium subcritical core developed by the Manhattan Project. With Japan’s surrender, that core was instead kept for testing, as it was no longer needed to end the conflict. During two tests at the Los Alamos Laboratory in New Mexico, two incidents occurred where the core was placed in a critical condition, resulting in a deadly wave of radiation that took two lives.
These two incidents are what earned the U.S.’ third core the name “Demon Core.”Because of these incidents, the Demon Core became something of a scientific cautionary tale, as it showed how some science experiments could have terrifying consequenceseven in a controlled setting. The Demon Core was melted down in 1946, but it remains a constant reminder of the dangers of the early Atomic Age.
Two people were exposed in the first incident
The first deadly incident involving the Demon Core occurred on August 21, 1945. During the experiment, a critical assembly was developed using tungsten carbide bricks. Weighing 9.7 lbs. each, these bricks were placed around the core. Just as the final brick was being put into place by Dr. Harotune”Harry” Krikor Daghlian Jr., he noticed by looking at a neutron counter that adding the final brick would place the core into a supercritical state. Upon seeing it, he withdrew his hand.
The brick he was holding slipped and dropped right on the center of the experiment, making it prompt critical.This is a dangerous increase in power resulting from a chain reaction resulting from prompt neutrons alone, which are emitted immediately during fission. A blast of energy occurred as he quickly pushed away the final brick and began tearing down the others. Unfortunately by this time, he’d already been exposed to 510 rem from a fission yield of 10^16. To put it in plain English: He received a fatal dose of radiation.
A dose of between 400 and 500 rem results in a 50% mortality rate, but anything above 500 is considered to be a lethal dose. Dr. Daghlian died 25 days after exposure, but he wasn’t the only one affected. A nearby guardassigned to the building,Army Pvt. Robert J. Hemmerly, alsoreceived a dose of around 50 rem, which is enough to cause injury. Hemmerly died from Leukemia 33 years after his exposure.
Eight people were exposed in the second incident
The second incident of accidental lethal exposure from the Demon Core occurred on May 21, 1946, when a larger group of people observed the creation of a metal critical assembly. Instead of tungsten carbide, the core was placed into two hemispherical beryllium shells. As the top hemisphere was lowered into place to cover the Demon Core, one edge made contact with the bottom beryllium hemisphere, while the edge on the other side was resting atop the end of a screwdriver, which slipped.
The contact led to another onset of fission, resulting in 3 x 10^15. There were eight people in the room, and they all received varying degrees of radiation. These amounts were measured to be 2,100, 360, 250, 160, 110, 65, 47, and 35 rem. The man who was lowering the top hemisphere into place, Dr. Louis Alexander Slotin, received the 2,100 rem dose, as he used his body to shield his colleagues from as much radiation as possible while he dismantled the assembly.
He died less than two weeks after the incident of acute radiation syndrome, while the other people gathered in the room received injuries of varying degrees of severity. After the second incident resulted in yet another death, the Demon Core earned its name. It was later melted down so it could be used to fuel future nuclear weapons. While these two incidents were horrific, resulting in the deaths and overexposure of numerous people, subsequent medical studies on the exposures aided scientific knowledge of how radiation affects the human body.
