Everything Everywhere Daily: History, Science, Geography & More - The Manhattan Project

Starting point is 00:00:00 During the Second World War, the United States embarked on one of the greatest science and engineering projects the world had ever seen. Over 125,000 people took part in the program, the vast majority of which had no clue what it was for, and the total cost of the program was over a billion dollars, at a time when a billion dollars was a lot of money. The end result was the most devastating weapon ever created, and it fundamentally changed the world. Learn more about the Manhattan Project and how the atomic bomb was created on this episode of Everything Everywhere Daily. What if your perceptions about the past were wrong? ThruLine is a podcast that takes you back in time to uncover the parts of the story that may have

Starting point is 00:00:54 gone unnoticed. It effectively turned day into night. And how it shaped the world now. Time travel with us every week on the ThruLine podcast from NPR. I've done a fair number of episodes detailing with the development and creation of the atomic bomb. I've discussed various nuclear tests, the Nazi atomic bomb program, the Trinity test, and a host of related subjects. However, I have not done a full episode on the central subject of the development of the atomic bomb,

Starting point is 00:01:28 the Manhattan Project. The Manhattan Project was one of, if not the most important, scientific and engineering programs ever undertaken, and the legacy of the program can still be felt today. The story of the Manhattan Project actually begins in 1938 in Germany of all places. It began with the discovery of nuclear fission by German scientists Otto Hahn and Fritz Strassman in December 1938, followed by the theoretical explanations by Lisa Metner and Otto Frisch. They found that it was possible to split the nucleus of a uranium atom and in the process release a tremendous amount of energy. This news shook the world of physics. It didn't take long for physicists to understand the ramifications of this discovery.

Starting point is 00:02:13 A controlled chain reaction of splitting uranium atoms could lead to an incredible amount of energy that could be harnessed by society. However, an uncontrolled chain reaction could lead to a tremendous explosion, the likes of which had never been seen in history. The fact that the discovery of fission had taken place in Nazi Germany terrified some of the leading physicists of the day. They feared what would happen if Hitler were to get his hands on such a weapon. Two of the physicists that were concerned were German-born Albert Einstein and Hungarian-born Leo Salard.

Starting point is 00:02:48 On August 2nd, 1939, just weeks before the German invasion of Poland, they wrote a letter to the American president Franklin Roosevelt, urging the United States to start its own atomic research program. Roosevelt appointed Linman Briggs of the National Bureau of Standards to head the Advisory Committee on Uranium. The committee reported back to the president in November of that year that, uranium, quote, would provide a possible source of bombs with a destructiveness vastly greater than anything now known. The United States was still not in the war, so limited funding was given to general research in an attempt to create an atomic reactor, or what at the time was called an atomic pile. In June of 1940, the Advisory Committee on Uranium was renamed the National

Starting point is 00:03:34 Defense Research Committee on Uranium. The next important date was a year later, on June 28, 1941. President Roosevelt signed an executive order that created the Office of Scientific Research and Development, or OSRD. Its director was Vannevar Bush, a man who was worthy of his own future episode. The OSRD took in the National Defense Research Committee on Uranium and renamed it the S-1 Committee, a purposely ambiguous name. They were given a budget to research uranium 235, the fissile isotope of uranium, as well as plutonium which had just been discovered in February. of that year. Over in the UK, a separate research project was underway. In 1940, they established the Maud Committee to investigate the uses of uranium and later plutonium. They made some advancements in determining the critical mass of uranium 235 required for a bomb, as well as developing

Starting point is 00:04:28 a plan for how to possibly separate uranium 235 from uranium 238. As early as July 1940, the British offered to share what they knew with the United States. Physicist Henry Tissard came to the U.S. to exchange information on radar and other technologies. What he discovered was that at the time, the U.S. atomic program was much smaller and further behind than the British. The British Maud Committee eventually became the tube alloys program, which was intended to be more than an investigation and an actual program to create an atomic weapon. However, the British didn't have the resources to actually create it during the war. And the Americans were not interested in sharing their information at that time. Everything up until this point was mostly theoretical investigations.

Starting point is 00:05:14 What changed everything was the American entry into the war in December 1941. Now that the United States was at war with Germany, the need to develop a bomb before Germany became paramount. In early 1942, the S-1 committee began planning for the actual development of a bomb. Ernest Lawrence of the Berkeley Radiation Laboratory proposed creating a nuclear chain reaction by July 1942 and an atomic bomb by January 1945. His timeline seemed very ambitious. In June of 1942, the project was transferred to the newly established Army Corps of Engineers Manhattan Division.

Starting point is 00:05:52 The Corps of Engineers named its districts after regions or major cities where the headquarters were located. When the project was first transferred to the Army, its first offices were located in Manhattan, and hence it was dubbed the Manhattan Project. The name stuck precisely because it wasn't descriptive and conveyed nothing about the project's purpose. The first order of business was selecting locations for the actual construction of the bomb. While over a dozen sites were used, there were three primary locations. The first was in Oak Ridge, Tennessee, just outside of Knoxville.

Starting point is 00:06:26 It was to be the primary facility for uranium enrichment. The second major facility was near the town of Hanford and central Washington State on the banks of the Columbia River. This was to be the processing center for the creation of plutonium. On September 23rd, Brigadier General Leslie Groves was appointed to lead the Manhattan Project, and on October 19th, Robert Oppenheimer was appointed as the scientific director of the Los Alamos Laboratory. Los Alamos was to be the third major facility. This location was originally known as Project Y, the primary scientific laboratory where the bomb's design and testing was to be conducted.

Starting point is 00:07:02 It was decided that Project Y should be located in a remote area, and the area selected in New Mexico was one near where Oppenheimer owned a ranch. In December 1942, Enrico Fermi and his team at the University of Chicago developed the world's first human-made self-sustaining nuclear chain reactor, just six months after Lawrence's prediction. Construction began in the facilities in Oak Ridge and Hanford in January, 1943, and the Los Alamo Center opened in March. In April, Oak Ridge received its first shipment of uranium, and by August, its first nuclear reactor, the X-10 graphite reactor, began operation. Here I should note that when this story of the Manhattan Project is often depicted in movies and television, it almost always revolves around Los Alamos. This is understandable, as this is where all of the celebrity scientists were assembled. For perhaps the only time in history, a collection of some of the world's greatest minds all lived and worked in close. proximity to each other. Although vitally important, the Los Alamos facility was just a small

Starting point is 00:08:09 part of the overall program. The vast majority of money and staff were all employed at Oak Ridge and Hanford. While the team at Los Alamos was busy working on the designs of the bomb, no matter what design they used, the raw components of the bomb were going to be some combination of uranium 235 and plutonium 239. Creating these raw, materials was the single most challenging part of the entire Manhattan project. This is what many physicists thought was going to be the thing that prevented the bomb from being built. Uranium comes in two naturally occurring isotopes, uranium 238, which makes up 99.3% of all natural uranium, and uranium 235, which makes up 0.7%. The problem is that both U-238 and U-235 are the same element,

Starting point is 00:09:01 and behave exactly the same chemically. There is no chemical process that you can use to separate one from the other. There were several different methods that were proposed for how to separate the different isotopes of uranium. The first was electromagnetic separation. This was a highly inefficient method that used the property that a magnetic field would deflect charge particles according to their mass. As the two isotopes had slightly different masses, you could separate one from the other. However, this was painfully slow as you had to almost do it atom by atom. I remember a professor who ran the mass spectrometry lab when I was in school,

Starting point is 00:09:42 explaining how he could theoretically enrich uranium with his mass spectrometer using this technique, but it would take decades to get an amount that you could even begin to manipulate. This was the first method pursued, not because it was the best method, but because it was known that it would at least work. Another method was gas diffusion. This method was much more promising but had bigger technical challenges. For starters, you had to make uranium hexafluoride, a highly corrosive gas. You use the property that when gases pass through a semi-permeable membrane,

Starting point is 00:10:16 lighter mass gas particles tend to go through before heavier ones. You could separate the uranium hexafluoride gas that contained U-238 this way. However, you had to iterate it over and over. and over. In November 1942, a gas diffusion plant was approved and was given the code name K-25. When the plant was finished in 1944, the K-25 facility was the world's largest building. It had over 5.2 million square feet, or 489,000 square meters of floor space, and a volume of 97.5 million cubic feet or 2.7 million cubic meters. Finally, a liquid thermal diffusion plant was built.

Starting point is 00:11:02 Thermal diffusion takes advantage of the property of fluids that, over a temperature gradient, lighter molecules move towards the hotter side, with heavier ones tending to go to the cold side. Over in Hanford, they were working on creating plutonium 239, an element that is not found in nature. To do this, they created three nuclear reactors, where they bombarded uranium 238 with neutrons.

Starting point is 00:11:24 some of these uranium atoms would then decay after a series of steps into plutonium 239. As plutonium wasn't natural, scientists initially had no idea how plutonium behaved chemically, so they had to figure out how to separate uranium from plutonium, which required plutonium that could be used for experimental research. To put the relative sizes of each facility into perspective, the Los Alamos facility in New Mexico only had about 8,000 people, working there, including the families of the scientists. Oak Ridge had a workforce of about 75,000 people, and Hanford had about 50,000. This was on top of building some of the biggest

Starting point is 00:12:07 industrial facilities on the planet. One of the big problems they had was keeping operational secrecy with so many people working there. The vast majority of the over 125,000 people who worked in some way on the Manhattan Project had no idea what they were working. on. They just knew it was something scientific for the war effort. About 85,000 of those people were construction workers, with another 40,000 who worked at the plants. Most people only knew their small role and didn't know what anybody else was doing. The total cost of the Manhattan Project was $1.8 billion by the end of the war. While that was an enormous amount of money for the 1940s, it actually only represented about nine days worth of spending during the war.

Starting point is 00:12:57 Inflation adjusted, it would be about $25 billion today. Despite the large budget, almost no one in Congress was aware of the program. Near the end of the war in Europe, in March of 1945, there were only seven members of Congress who had been briefed on the Manhattan Project. The end result of the work of tens of thousands of people, almost $2 billion in spending, and some of the largest buildings on the planet was shockingly small. Oak Ridge managed to create a whopping 50 kilograms or 110 pounds of uranium 235, which, it should be noted, is a very dense metal. Hanford managed to produce just 6 kilograms or 13.2 pounds

Starting point is 00:13:41 of plutonium 239. Despite these seemingly small amounts, the U-235 was enough to create the little boy bomb that was dropped on Hiroshima on August 6, 1945. The plutonium 239 from Hanford was enough for two bombs, the one used at the Trinity Test explosion in New Mexico, and the Fat Man bomb dropped on Nagasaki. There was actually a great deal of doubt as to if they should conduct the Trinity test explosion because of the high cost of the plutonium involved. The Manhattan Project was one of the largest single science and engineering programs that the world had ever seen, and the biggest until the Apollo program. It changed the world. Not only

Starting point is 00:14:25 did it end the Second World War, but it ushered the world into an era of nuclear weapons. The executive producer of Everything Everywhere Daily is Charles Daniel. The associate producers are Benji Long and Cameron Kiever. I want to give a big shout out to everyone who supports the show over on Patreon, including the show's producers. Your support helps me put out a show every single day. And also, Patreon is currently the only place where Everything Everywhere Daily merchandise is available to the top tier of supporters. If you'd like to talk to other listeners of the show and members of the Completionist Club, you can join the Everything Everywhere Daily Facebook group or Discord server. Links to everything are in the show notes.

Everything Everywhere Daily: History, Science, Geography & More - The Manhattan Project

There aren't comments yet for this episode. Click on any sentence in the transcript to leave a comment.