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Profiles In Badassery: Harry K. Daghlian Jr.

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After doing the preview on Iowa earlier this week and mentioning that we can build The Bomb I started thinking more about nuclear engineering. We have several nuclear engineers as regular readers in Boiler_nuke, BoilerPaulie, and PurdueEnginerd. These are the guys that can make the atoms dance and will likely discover wonderful things like cold fusion while I am busy typing away here. This passing interest in nuclear engineering got me looking at our past alumni, and that led me to today's subject for a Profile in Badassery.

It takes a man with balls of steel to physically stop a nuclear pile from going supercritical. Sure, it cost this dude his life, but he prevented an even bigger accident from costing even more lives. I am referring to a martyred Boiler by the name of Harry K. Daghlian, Jr., who was working to make the world safe for democracy against those evil Commie Bastards when he was forced to give his life to save others from certain death.


Daghlian was a young man fresh out of Purdue when he died. He was born May 4, 1921 in Waterbury, CT and was the son of an X-ray technician. He soon moved to New London, CT where he would complete his elementary and secondary education. His uncle had a large influence on him, as Dr. Garabed K. Daghlian was a professor of physics and astronomy at Connecticut College in New London.

In 1938 the younger Daghlian graduated first in his class of mathematics from Bulkeley High School and at age 17 he was able to begin undergraduate studies at MIT. He would eventually transfer to Purdue because he was fascinated with physics, especially particle physics. Particle physics wasn't exactly that popular in 1940, so Daghlian was able to be on the leading edge of a field that would have a high demand in the very near future.

Daghlian graduated from Purdue in 1942 and began graduate studies in West Lafayette. He also became a physics instructor while he worked on his graduate studies.

The Manhattan Project

Daghlian was at Purdue during the height of World War II. As the war progressed particle physics became an area of interest within the government, specifically because it could yield a potential weapon to use against the Nazis or Japanese. The Nazis had their own nuclear program going, and each was top secret in their respective countries. Our program was named The Manhattan Project and headed by Dr. Robert Oppenheimer, who was in a race to create an atomic bomb before the Germans. From Daghlian's online biography:

1943 would prove to be a pivotal year for five Purdue physicists and their families. In the spring of that year, Oppenheimer was busily recruiting scientific personnel for Los Alamos and the majority of early recruits consisted of scientists with whom he had previous or ongoing collaborations. It was in this context that Marshall Holloway was invited to give a lecture at Los Alamos in the spring of 1943, and Oppenheimer used that occasion to recruit Holloway's group from Purdue. On returning, Holloway announced his intentions to transfer to Los Alamos after completion of cross-section studies of tritium and deuterium (T-D cross-sections). In addition to Holloway, his group consisted of three senior-level investigators - Charles "Charlie" P. Baker, Lionel Daniel Percival "Perc" King and Raemer E. Schreiber. A young graduate student, Harry K. Daghlian Jr., would help in finalizing the Purdue studies, and would join them in Los Alamos at a later date.

Working on the Manhattan Project was perhaps the most top secret work in the history of the country. These scientists were tasked with racing against time in an already heightened wartime environment. Only the brightest and most trustworthy minds were asked to work on it. Daghlian contributed what he could from Purdue while he was finishing up his graduate studies. He specifically worked with Purdue's cyclotron, rebuilding it to produce 10-MeV deuterons. I have no idea what that means, but it sounds pretty cool.

Daghlian headed to Los Alamos in the spring of 1944 where he worked as part of the "Water Boiler" group at the Omega Site; he later joined the Critical Assembly Group or "crew" that was headed by Otto Frisch, also located at Omega. These studies included the well-known "tickling the dragon's tail" experiments. Daghlian's last major assignment was as an assistant in preparing the plutonium core at the MacDonald Ranch House for the Trinity test in Alamogordo, NM.

Trinity site:

The Trinity site is the famous place in New Mexico where on July 16, 1945 the U.S. successfully tested the world's first nuclear weapon. No one really knew what would happen. Some thought there was a small chance the explosion would set the earth's atmosphere on fire and kill all life on the planet. I don't know about you, but if there is even a small chance of incinerating the entire planet I want to make sure I have a Purdue nuclear engineer on site to make sure that doesn't happen. I don't want to burn up the earth. I keep all my stuff there.

The test was successful, and three weeks later we dropped the first wartime atomic bomb on Hiroshima. A second bomb was dropped on Nagasaki a few days later and World War II was brought to an end on August 15, 1945. It is estimated that the use of the atomic weapons saved millions of casualties on both sides had an invasion of Japan occurred.

Daghlian's accident:

Daghlian did not have long to enjoy America's victory over Japan. He continued to do research at the Los Alamos site for future nuclear weapons when he was involved in a deadly criticality accident on August 21, 1945. Here are the details of the accident:

On 21 August, 1945, Daghlian was involved with a series of experiments at Omega Site concerning the critical masses of a 6.2 kg sphere of plutonium (Pu-239 or "49 metal") in various tungsten carbide (WC) tamper arrangements. On the morning of August 21, 1945, he constructed a hollow cube on a square base (14-7/8 inches per side) from WC bricks (2-1/8 x 2-1/8 x 4-1/4 inches) surrounding the 49 metal sphere. This assembly was found to be critical when five layers were completed and two additional bricks were placed in the middle of the sixth layer.

That afternoon, Daghlian constructed another cube on a 12-3/4 inch square base of WC bricks for enclosing the same 49 metal sphere. This time, the assembly became critical when five layers were completed, and the task of designing an appropriate assembly configuration, i.e., the 49 metal sphere enclosed in a completed cube, remained to be determined. As he disassembled the afternoon experiment and returned the Pu-239 sphere to the vault, Daghlian began planning the next criticality test and, after making some final remarks in his notebook, he decided to construct the next assembly on a 10-5/8 inch square base.

After dinner, Daghlian attended a scientific lecture at theatre #2, and began thinking about returning to Omega Site that evening to test the third assembly, rather than the following morning as originally planned. He was well aware that this was against "official" safety regulations on two counts, i.e., performing a potentially hazardous experiment alone after-hours. By the end of the lecture at 9:10 PM, his mind was made up, for reasons that are even today unknown, and he proceeded directly to Omega, arriving there at 9:30 PM.

Entering the laboratory, he found Private Robert J. Hemmerly, a Special Engineer Detachment (SED) guard, seated at a desk and reading a newspaper. Hemmerly looked up apprehensively at a somewhat anxious Daghlian, who tried to mask his nervousness by walking directly to the assembly bench. SED guards were stationed at Omega whenever fissionable material was onsite, in case of fire and, especially, as a deterrent to theft. Hemmerly's responsibilities did not extend to policing conduct or enforcing laboratory regulations, and his apprehension quickly faded with a return to his newspaper and a "Hi, Harry" in the direction of the moving figure.

Daghlian immediately set about removing the 49 metal sphere from the vault and constructing the planned assembly. Using the audible "clicks" of the monitoring instruments as a guide, he quickly completed four layers. His pace slowed as he started the fifth layer and he finished half of it. As he attempted to place another brick over the center of the assembly with his left hand, the "clicks" alerted him to the possibility that this addition would be supercritical, and he immediately started withdrawing his left hand when the brick fell from his grasp into the center of the assembly. Reacting instinctively, he pushed the brick from the assembly with his right hand, which developed a tingling sensation as it became enveloped in the blue glow surrounding the sphere. The time was 9:55 PM.

The moving of the brick was not enough to stop the pile from going supercritical and Daghlian was forced to disassemble the pile by hand in order to stop the reaction. Naturally, being around that much radiation is not necessarily a positive thing for a human being. He received a dose of 510 rems of neutron radiation as the result of a yield of 1016 fissions.

Daghlian was rushed to the hospital, where he immediately began showing symptoms of acute radiation poisoning. There would be no time for a 90 day review, nor would any amount of exercise help him out here. An extreme body workout would not help him expunge the radiation, and he would not be able to earn a beach body. His hand that was holding the brick began to swell and he developed overwhelming nausea. Over the next 25 days his symptoms became worse and worse as he was slowly and painfully dying. On September 15, 1945 he passed away from acute radiation poisoning. There wasn't really anything that could be done to save him because of the large amount of radiation he absorbed.

Daghlian's accident helped lead to improved safety practices in nuclear research. It is unfortunate that it took his death to change things, but some things can only be learned painfully. While he was the cause of the accident, Daghlian earned his stripes in Badassery by sacrificing himself to prevent an even larger accident.

This is a guest post provided by Fitness Alliance