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## Hotspot
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## Popup
### Body
htmlText_96986827_85DE_8345_41E0_9218F5B6D1C7.html = At the heart of the B Reactor is the pile or nuclear reactor. It was modeled after Enrico Fermi's CP-1 and later experimental piles. But the scale of the B Reactor dwarfed all aspects of its predecessors. This one tenth scale model shows the internal structure of the reactor core as well as piping and safety systems associated with the reactor.
Graphite Blocks:
Behind the visible front face are 75,000 graphite blocks precisely laid in place by bricklayers. These blocks are 36 feet wide (10.97 m), 36 feet tall (10.97 m), and 28 feet (8.53 m) front to rear. The graphite serves a valuable purpose in making the fission (splitting apart) happen. The graphite moderates (slows down or reduce the energy of) the fast (high energy) neutrons released by the fissioning of a uranium 235 nucleus. The slowed neutrons are then able to do two things: impact other U-235 atoms, causing another fission (a chain reaction), or be absorbed by the more plentiful U-238 atoms that might then undergo the transmutation process to plutonium 239. Don’t worry—uranium in the natural world would not just start a chain reaction, rather it’s the graphite that creates the artificial conditions for a controlled chain reaction.
Process Tubes:
On the front face of the reactor are the 2,004 aluminum process tubes, running from the front face to the rear face of the pile, that hold the uranium fuel and carry the cooling water. When fully loaded, the reactor contained up to 64,000 aluminum-clad fuel slugs. Each fuel slug was approximately 8 inches (20.3 cm) long and approximately 1.5 inches (3.81 cm) in diameter and weighed about 8 pounds (3.63 kg)—about the size of two regular snickers bars stacked end to end but much heavier. A full load of reactor fuel equaled approximately 250 tons (7.25 mt) of natural uranium. That is equivalent to the approximate weight of two average-sized blue whales, the largest mammals on earth.
Shielding:
The reactor has many different layers and types of shielding to protect the reactor operators. The levels of radioactivity and heat in the reactor are intense. The graphite pile sits on a thick concrete foundation (needed for the weight of the reactor) and is surrounded by a cast iron thermal shield designed to keep the heat in. Surrounding this is a biological shield that prevents neutrons and gamma radiation from escaping the pile and harming biological organisms, humans mostly, and is comprised of 50 inches (127 cm) of alternating steel and Masonite layers. Masonite, more commonly known as the stuff clipboards are made up of, has a high hydrogen component, and hydrogen is great at blocking and slowing down fast neutrons. The entire pile, seams and seals, was welded gas-tight—or completely sealed up so air and gas would not get in or out.
Image Credit: Photo courtesy of D. Marsh
Between the physicists of the Metallurgical Lab and the DuPont engineers and supervisors was a large workforce of skilled and unskilled workers. Recruitment of workers was paramount to the success of the Hanford Engineer Works (HEW) and was hampered by the fact that most able-bodied men, 38 years of age or younger, had been drafted into the military service. DuPont worked with 11 War Manpower Commission offices to staff the project in the spring of 1943. At Hanford, approximately 260,000 people were interviewed and around 120,000 were hired. Despite those massive numbers, the high point of the workforce was approximately 45,000 at any one time as there was a significant turnover in personnel, due both to the rough living conditions and the normal progression of crafts needed during construction.
Hanford workers came from all 48 states and over 700 communities. About 4,000 of the workers were women. Most of the women were in the Women’s Army Corp (WAC). Women worked as secretaries, drivers, nurses, payroll staff, waitresses, maids, researchers, glass blowers, and lab technicians to name a few.
African Americans numbered over 15,000 at Hanford. They came mostly from the southern states and worked in segregated work groups. African American men were generally hired for unskilled labor while women were hired for domestic roles such as maids and waitresses despite promises of clerical work by recruiters. Pay was the same between White and Black workers due to recently passed laws governing wages on defense contracts.
On the Hanford site, there were eight mess halls that served meals 24 hours a day. Meals cost workers 67 cents a day and were all-you-could-eat…and workers ate a lot. Each day 200 pounds (91 kg) of butter was used for sandwiches, 120 tons (181 mt) of potatoes were served, and 32,000 glasses of milk were drunk. Workers consumed 250,000 pounds (113,398 kg) of meat and drank 13 car loads of beer each week. A lot of calories were needed to power the Hanford workforce.
Image Credit: US Department of Energy
Does this panel remind you of an old-fashioned telephone operator switchboard? That’s because it is! This is a great example of the creativity and ingenuity required to build something that had never been built before.
Operators were able to monitor plutonium production within the individual process tubes in part by monitoring the temperature of the water that exited the rear face. Operators would record the temperature of this water every day. It took two men three hours to complete this task.
In the early 1950s, an automated method for collecting this information was created, using this Flexo-writer. Thermocouples at the discharge end of each process tube that were connected to the Flexo-writer and it took only ten minutes for this machine to collect the data. Information was displayed in real time and recorded on to paper tape. This information, along with inlet water temperature and water pressure was then used in a series of calculations that estimated how much plutonium was produced and which process tubes were ready to be discharged.
Image Credit: US Department of Energy
Due to the incredible amount of water rushing through the pipes in the valve pit, it was nearly impossible to have a conversation here. Sound absorbing materials were added to this telephone booth, and once modified, it was christened a “Hear Here.” This booth provided a quiet place for workers to communicate to other parts of the reactor building. The noise level in the valve pit was significant enough to warrant hearing protection.
Image Credit: NPS/Burghart
From Dr. Strangelove to the Teenage Mutant Ninja Turtles, the nuclear age has and continues to influence popular culture. This Atomic Culture exhibit highlights just a few examples in cinema, literature, and music of how we collectively grapple with the profundity of the nuclear age.
Image Credit: NPS/Burghart
Fuel spent a varying amount of time in the reactor, depending on where it was located within the core. Fuel in the center of the reactor received the greatest amount of neutron radiation and it might spend as little as four to six weeks, while fuel around the outer edges might spend six to nine months.
Every four to six weeks of operation, workers would shut down the reactor and go through a charge-discharge process replacing 10-20 percent of the fuel in the reactor. Fresh fuel would be pushed into the front of the reactor, which would cause the now highly radioactive discharged fuel to come out the rear of the reactor. The fuel would fall into the fuel storage basin, a 20-foot (6.10 m) deep water-filled pool. The water protected the workers from the dangerous levels of radiation given off by the irradiated fuel.
Workers leaned over railings above the basin and used long tongs to place fuel into baskets. Once the baskets were loaded, they would be moved via the monorail system to the storage area of the basin where the irradiated fuel would be held for approximately 90 days to thermally and radiologically cool off. Thermocouples at the inlet and outlet of the storage basin measured water temperature, which was used as an indicator of radiation levels.
Once sufficiently cooled, the fuel was moved to the transfer area. There, a large overhead crane transferred the fuel baskets into water filled casks. These casks were then put into lead lined tanks on a flatbed rail car. Once loaded, the fuel was transported by rail to the T Plant to chemically separate the plutonium from the uranium and other radioactive byproducts produced during irradiation.
Image Credit: US Department of Energy
If you have ever stood near a thundering waterfall, you know it is hard to have a conversation with anyone nearby. The deafening sound of rushing water filled the reactor and most acutely in the valve pit. This is where the water for cooling the reactor entered the building. Initial water flow was approximately 27,000 gallons (100,000 l) per minute of water pumped from the Columbia River. When the reactor power level was increased to 2,000 megawatts in the 1950s, the water flow increased to approximately 70,000 gallons (264,978 l) per minute. This is a comparable water supply for a city with a population of 60,000 people.
Large diameter pipes delivered the much-needed cooling water to the valve pit. From there the water was divided into two sets of pipes that ran under the floor of the front race room. One set of pipes fed the right side of the reactor and the other fed the left side. If the flow of water to the reactor was ever interrupted, the reactor could overheat and melt down or irreparably damage the reactor core. DuPont understood this danger and developed backup systems to prevent such a disaster.
DuPont developed multiple backup systems in case the electricity powering the pumps was ever interrupted. The engineers were always driven by the question—what if? What if the plant lost electric power? What if one set of the valves for the water supply failed or a water supply pipe failed? Therefore, they designed backup systems that did two things: protected the reactor and workers and minimized down time. A coal-fired plant was on site with a six-month supply of coal. It maintained constant steam pressure of up to 80 percent. Should the electricity fail, the pumping system would kick over to steam engines in 20 seconds.
If the steam powered pumps failed, there were two water towers that stored enough gravity- fed water to keep water flowing for a few hours giving operators ample time to shut down the reactor. If all else failed, water could be drawn from other reactors through underground water pipes.
Image Credit: US Department of Energy
Lise Meitner (pictured) was the first woman to become a full professor of physics in Germany. She lost her position due to the anti-Jewish laws in Nazi Germany and fled to Sweden in 1938. Despite this, Meitner continued working with her German colleagues, Fritz Strassman and Otto Hahn, by correspondence. In Berlin, Hahn achieved nuclear fission during an experiment but did not realize it. Hahn asked Meitner for help in explaining his puzzling results. Meitner, aided by her nephew Otto Frisch, correctly interpreted that Hahn had split the atom. Meitner was the first person to articulate the process of nuclear fission. Prior to this discovery, it was though the atom could not be split. The term atom comes from Ancient Greek for “impossible to cut,” or in other words, atoms could never be divided into anything smaller. The discovery of fission was a true revelation, one that would alter the human experience with the dawning of the nuclear age in less than a decade.
Learn more about fission in the above audio file.
Image Credit: Photo courtesy of Archiv der Max-Planck-Gesellschaft, Berlin-Dahlem
One operator sat in front of the main control panel in the control room (pictured) where he could watch the instruments that displayed the pile's power level and control rod positions. This position would be occupied 24 hours a day whether the reactor was operating or shut down.
An annunciator displayed 28 conditions, any one of which would automatically scram the pile or sound an alarm for operator intervention. The operator could adjust the control rods to maintain the pile's reactivity at the specified level and could also push a button to scram the pile when it was deemed necessary.
The word scram has been in use in the English language since the late 1920s, meaning "to go away at once," especially if you weren't wanted. The term was adopted early in the new field of nuclear reactors to denote a fast shutdown of the pile, especially in potentially dangerous situations.
Four other instrument panels in the control room monitored thousands of different conditions in the pile, including:
• Water pressure at the inlet of each of the 2,004 process tubes
• Water temperature at the outlet of each process tube
• Water flow through the pile
• Water supply pressure
• The state of the helium gas system
• Radiation in various parts of the building
Several other operators would monitor these instruments. They would rotate their jobs among the different gauges during their shift to maintain their alertness and accuracy.
Image Credit: US Department of Energy
Our collective fascination and fear of nuclear technology is expressed in popular culture in many ways, from the atomic awakening of mutant creatures to a comically inept nuclear safety operator.
We have used poetry to express ourselves for centuries. One popular form of poetry is a Japanese haiku. A traditional haiku consists of three short lines that do not rhyme in a pattern of five syllables, seven syllables, and five syllables. The modern form of a haiku does not follow this set pattern but still uses short lines and colorful descriptions to illuminate a brief moment in time.
What does the nuclear age mean to you? Share your answer by writing a haiku.
For detailed pictures, exhibit text, and image descriptions visit A Haiku for You.
Image Credit: See exhibit panel for specific image credits
Scientists are often driven by curiosity and the desire to learn, make discoveries, and find answers. Chadwick, Meitner, Fermi, McMillan, and Seaborg experimented over and over until they discovered answers to big questions that made the nuclear age possible.
What inspires your curiosity and motivates you to learn and experiment?
For detailed pictures, exhibit text, and image descriptions visit the Scientific Curiosity exhibit panel.
Image Credit: See exhibit panel for specific image credits
The Columbia River with its ample supply of cool clean water was the primary reason Lieutenant Colonel Franklin Matthias recommended the Hanford Site to General Leslie Groves, head of the Manhattan Project. Groves directed Matthias to search the United States for the perfect location to produce plutonium. In addition to a large source of water, Matthias also needed to find a vast area of land that had access to plentiful amounts of electricity, accessible rail service, and no large cities or major highways nearby. When Mattias flew over what would become the Hanford site in December 1942, he knew he found the perfect location for plutonium production. The Hanford area is 586 square miles (1,517 sq km) in size, only three small communities—Richland, White Bluffs, and Hanford (the namesake of the Hanford site)—were nearby, and the newly built Grand Coulee Dam and other dams on the Columbia River provided the needed electricity. Groves approved the acquisition of the Hanford site in January 1943, and construction began that summer.
During initial operation, the B reactor was designed to operate at 250 megawatts and used approximately 27,000 gallons (100,000 l) per minute of Columbia River water to cool the reactor core. Water was pumped from the river to a filter plant. Once the water was filtered, it came into the reactor in large diameter pipes. Every second 400 gallons (1514.16 l) of water passed through the reactor. In that one second of time those 400 gallons (1514.16 l) would go from ambient Columbia River temperature with a seasonal average of about 53.6 °F (12 °C) to nearly boiling at 190 °F (88 °C). Once the water left the reactor it flowed to a retention basin where it stayed on average three to four hours for short-lived radionuclides to decay before the relatively thermally hot water was discharged into the Columbia River. While it may sound alarming that hot water was discharged into the river, during operation the discharge amount was a very small fraction of the river water, and the hot water was quickly diluted.
Image Credit: US Department of Energy
The Manhattan Project is one of the most transformative events in human history. It is a story of humans learning to control the power of the atom, which is akin to when humans learned to control fire. The Manhattan Project dawned the nuclear age, and the B Reactor (pictured in 1944) played a key role in ushering in this new age.
The B Reactor on the Hanford Site in south-eastern Washington state is the first full-scale nuclear production reactor in the world. At the height of the Manhattan Project’s over 45,000 people from all walks of life and all 48 states worked at the Hanford Site. While many of the workers did not know their mission, their combined efforts proved that plutonium could be produced on an industrial scale. Plutonium, only discovered three years prior in 1940 by chemist Glenn Seaborg and colleagues, was a viable fuel for the Manhattan Project and America’s Cold War nuclear arsenal.
Under a contract with the federal government the DuPont Corporation began construction on the reactor in October 1943, achieving criticality on September 26, 1944. The B Reactor’s sole purpose during the Manhattan Project was to produce plutonium to fuel for the Gadget, the world’s first atomic test device, and Fat Man, the atomic bomb the US dropped on Nagasaki, Japan, on August 9, 1945. The B Reactor continued operation until it was shut down in 1968. It remained in “cold standby” until 1978 when it was permanently shut down.
This virtual tour will take you on a walkthrough of the decommissioned B Reactor as it looks today. The granite marker at the entrance to the reactor includes plaques associated with the American Nuclear Society, the American Society of Mechanical Engineers, and the American Society of Civil Engineers signifying the completed milestones for designating the B Reactor a National Historic Landmark in 2008 and its inclusion in Manhattan Project National Historical Park in 2015.
Image Credit: US Department of Energy
The Manhattan Project launched the nuclear age and paved the way for future generations to live in a nuclear world. The reactor building where you are standing opened the door to this new age by industrializing the science that unleashed the energy held within the atom and made large-scale production of plutonium possible.
The decision to use the atomic weapon is one of the most consequential decisions of the 20th century. Imagine the outcomes and consequences that President Truman reflected on when he debated the decision to use the atomic bombs on Japan.
What do you consider when you make hard decisions? Do you rely mainly on the facts, your feelings, or a combination of the two? Write or draw your response to this question.
For detailed pictures, exhibit text, and image descriptions visit the Hard Decisions exhibit panel.
Image Credit: See exhibit panel for specific image credits
The discovery of the neutron set in motion a series of scientific discoveries that ultimately led to the launching of the nuclear age.
Atomic fervor swept in at the end of World War II. While dreams of atomic-powered cities, cars, and airplanes remain unrealized, many critical technological advancements were achieved. Developments in nuclear medicine brought new and effective treatments for cancer. Nuclear power plants powered cities without the release of greenhouse gases typical of fossil fuel power generation. Starting in the 1960s, as U.S. and Soviet leaders grappled with the gravity of nuclear war, they began a dialogue and negotiated international treaties to limit growth and development of the large nuclear arsenals stockpiled by both countries.
Today, the nuclear legacy of the Manhattan Project continues to influence global politics, science, and military power. It affects every person on the planet now and will continue to do so for many generations to come. How can we apply the knowledge of this history to responsibly manage the opportunities, as well as the dangers, of nuclear technologies? Write or draw your response to this question.
For detailed pictures, exhibit text, and image descriptions visit the Nuclear Age exhibit panel.
Image credit: See exhibit panel for specific image credits
The first "official" batch of irradiated fuel slugs from the B Reactor was processed at the T Plant beginning on December 26, 1944. On February 5, 1945, the first small batch of plutonium nitrate was ready for shipment to Los Alamos. This was Hanford's first product, and it was up to Col. Matthias to get it to Los Angeles, where he would transfer the material to a representative from Los Alamos. No armored cars were involved, nor any snaking convoys of military vehicles. Instead, Matthias hand-carried the plutonium, which was secured within the box in a small test-tube, surrounded by lead. He and an aide drove from Hanford to Portland, Oregon, where they caught a train to Los Angeles. There they met an officer from Los Alamos who would take the shipment by train the rest of the way.
Matthias later recounted the experience between him and the Los Alamos representative at the train station:
At the railroad station this officer came up and I said "Well, have you got a locked room to go back to New Mexico?" and he said "No, I had trouble getting it so I have a berth, an upper berth." So I said "Well, you know what you're gonna be carrying?" And he didn't know, so I said "Well, it cost $350,000,000." That was the cost of our project [Hanford] up to that point. So he kind of got a little bit shaky and went back to the station and came back with a locked room that he could use to get back.
After that, shipments were eventually made by Army ambulance-type panel trucks in a caravan of three trucks, with a car leading and following. This was believed to be a sufficiently safe method, because so many army vehicles were on the road at that time.
In Los Alamos, workers designed and built a device, known as the Gadget, to test an implosion-design plutonium-fueled atomic bomb. The Gadget used Hanford’s plutonium and was successfully detonated during Trinity test in New Mexico on July 16, 1945. The Trinity test was the first human-caused nuclear explosion in history and ushered in the nuclear age. A few weeks later on August 6, the Little Boy atomic bomb, fueled by enriched uranium from Oak Ridge, was detonated over Hiroshima, Japan, the first atomic weapon used in war. And then on August 9, 1945, the US dropped the Hanford plutonium-fueled Fat Man bomb over Nagasaki, Japan. This was the second atomic bomb used on a human population and, so far, the last.
Learn more about the Manhattan Project and its many legacies.
Image Credit: United States Marine Corps/Public Domain
The operators at B Reactor had more than 5,000 instruments to monitor. Some instruments displayed their readings, others recorded them, sounded an alarm, or controlled the reactor. Just about all of them were in the control room. It was here that personnel controlled the power level of the pile and monitored the reactivity of the pile, the temperature of the graphite and shields, the temperature, pressure, and flow rate of the cooling water, and much more. A minimum crew of three people would be stationed in this room 24 hours a day, 7 days a week.
Image Credit: US Department of Energy
The outer dress/undress corridor would have been stocked with respiratory protection (masks) and other clothing workers would don (dress) or doff (undress) while on a shift. Examples of masks used in the B Reactor during the operating years from 1944 to 1968 are on display in this room. Many of these masks bear the name MSA, which is an abbreviation for Mine Safety Appliances. As a new industry in the 1940s, the nuclear industry adopted safety standards from other industries as appropriate.
In an oral history, Jack Rhoades, a second-generation Hanford Worker whose career was quality assurance and safety said about Hanford safety standards:
“Because when they built the nuclear industry, they did not have safety standards for the nuclear industry, because it was a brand new industry. So, if you looked at the operation of the uranium side, then they used the safety standards of a steel mill and a blast furnace to do the safety standards for Fernald and these other uranium enrichment places. And if you look at the chemical processing in the canyons, they looked to the petroleum fracking industry for safety standards. And if you look at the waste disposal, which was the operation of the tank farms and the burial grounds, it had the same basic safety standards and the interest as a commercial landfill.”
Image Credit: US Department of Energy
The pile needed clean cooling water to prevent corrosion and buildup of scaling deposits on the aluminum fuel jackets and process tubes. The slightest impediment to water flow in the cooling tubes could make a substantial difference in the pile's plutonium output and its safety.
The TURCO pit is where solutions were prepared to clean the inside of the process tubes should any corrosion or contamination develop within the process tubes. TURCO is a brand name for industrial cleaning compounds. In the case of B Reactor, the chemical most used was a product containing diatomaceous earth. This material was mixed in the tanks in this pit and pumped through the existing water supply system to remove corrosion and other buildups that hindered water flow through the process tubes.
Image Credit: US Department of Energy
The purpose of the B Reactor was to make plutonium. The scientific discoveries of how to slow down neutrons and synthesize plutonium happened less than 10 years prior to the construction and operation of the B Reactor, which came online on September 26, 1944.
Enrico Fermi (pictured), a brilliant Italian physicist and professor teaching in Rome, received the 1938 Nobel Prize in physics partly for his discovery of the effects of slow neutrons on the fission process. After receiving the Nobel Prize, Fermi and his family fled to New York to protect his Jewish wife from rising anti-Semitism in Italy. Fermi continued experimental work with slow neutrons and soon theorized that a self-sustaining chain reaction was possible.
In 1941, Edwin McMillan and Glenn Seaborg led a team of scientists that synthesized plutonium for the first time in a laboratory at the University of California by using a cyclotron to irradiate uranium. These experiments laid the groundwork for future efforts to create plutonium on a large scale by means of a nuclear reactor.
In nature, the uranium atom has three isotopes: U-234, U-235, and U-238. Isotopes are like cousins—similar but different. Manhattan Project scientists were interested in U-235 because it is fissile, which means it can split and release neutrons. Scientists were also interested in U-238 because it can absorb neutrons released by U-235 and change into a whole new element. This change is called transmutation.
Through careful reactor design, scientists and engineers at Hanford achieved a sustained nuclear chain reaction in which U-235 continuously fissioned or split and thereby provided a continual source of fast neutrons. These neutrons were slowed using graphite as a moderator. The slowed neutrons hit U-238 atoms. When an atom of U-238 absorbed a neutron, it was transmuted, or changed into, neptunium, which then transmuted once again into plutonium 239, the product of interest.
Image Credit: Photo courtesy of Smithsonian Institution/Public Domain
The second floor of the accumulator room offers a bird’s-eye view of the accumulators, which are large tanks filled with river rock. Their purpose is to provide an automatic means to shut down the reactor should there be a loss of electrical power. Seven of the nine horizontal control rods were designated as shim rods, or rods that control the radioactivity of the reactor (the neutron flux) and have a poison, or neutron absorber, in them. Shim rods provide a baseline of control while the two remaining regulating rods performed minute-to-minute adjustments. The shim rods were operated by a hydraulic drive mechanism and the regulating rods were electrically driven.
These tanks provided a weighted hydraulic accumulator that stored oil under high pressure, like the hydraulic lift used to elevate a car in an auto repair shop. To safely shut down the reactor in the event of a power outage or other emergency, the electric clutch holding the tanks suspended above the floor would release and the weight of the accumulator would fall to the floor. This downward motion would pump the hydraulic oil in the horizontal control rod system to insert the shim rods into the reactor at the relatively fast rate of 30 inches (76.2 cm) per second, thus shutting the reactor down without any human intervention.
One notable instance of loss of electrical power occurred in the spring of 1945, when a Japanese Fu-Go Balloon Bomb (pictured) fell on the main electrical transmission line at Hanford, temporarily shutting down the reactor.
Image Credit: Public Domain
This exhibit explores the development of health physics, which is the science of protecting people and the environment from the potential harmful effects of radiation. The Manhattan Project introduced a new work-place hazard: radiation. Safety controls needed to be developed to ensure the safety of radiation workers. Learn about innovations at Hanford during the Manhattan Project that led to a better understanding of the effects of radiation on human health, enhanced protections for workers, and the emergence of a field that continued to protect lives long after the Manhattan Project ended.
Image Credit: US Department of Energy
This historic photo is also on the wall in the B Reactor. The image shows Hanford workers in the spring of 1944 gathered for a safety rally in the Hanford Construction Camp. These types of gatherings where one approach managers with the DuPont Company took to emphasize safety, security, and secrecy among the workforce.
The federal government contracted the DuPont Company for engineering, construction, and administration of the plutonium production facilities at Hanford. The company provided design, project and construction management, and critical engineering leadership. DuPont’s Board of Directors were hesitant to take on the project because of the negative reputation they had received after WWI when they were accused of huge profits from munitions and branded “merchants of death.” The board was also concerned about the many unknown variables of the project and the scale of the commitment.
DuPont requested a letter from President Roosevelt asking for clarification of DuPont's role in the project and refused any profits—agreeing to the contract only on the condition that DuPont would be reimbursed for expenses and receive one symbolic dollar as an award fee for completion of the project. In 1945, an article in a local newspaper stated DuPont received only 68 cents because an expense item of 32 cents was not allowed by an accountant. As a result, the Pasco Kiwanis Club collected one penny from each of their 32 members to make up the difference and sent it to DuPont.
DuPont also stipulated that within six months following cessation of hostilities their contract would be terminated. At that time DuPont had no corporate interest in the nuclear industry until 15 years after the war when DuPont shared information with the US Navy for development of their nuclear submarine program.
Image Credit: US Department of Energy
This is the final stop in the Reflection Room exhibits. Here cafeteria tables provide a quiet spot for visitors to sit and reflect. Throughout the Reflection Room exhibits, there are exhibits with prompting questions for visitors to respond to by writing in a lab notebook, typing a message using a vintage typewriter, creating a haiku using 3D printed words, and writing a post card to future generations. There is one hotspot in this room for each of the interactive exhibits in the History and Atomic Culture rooms. Take time to read these exhibits and write down your own thoughts and reflections on what the B Reactor, the Manhattan Project, and its many legacies means to you.
Image Credit: NPS/Hildebrandt
This is the front face of the reactor. First time visitors to the B Reactor often stop and gaze at the towering sight of the front face with its rows and rows of process tubes and “pig tails.” Some describe the B Reactor as a cathedral of science while others view it as a factory that made an essential ingredient in the most destructive weapons ever invented. As you navigate the labyrinth of hallways and 90 degree turns and learn about science and history of the Manhattan Project through this virtual tour, take time to reflect on what this place and the Manhattan Project and its legacies means to you. Does it ignite your scientific curiosity? Does it make you pause about the destructive power of nuclear weapons? Does it inspire hope for advances in nuclear medicine to find a cure for cancer?
Image Credit: NPS/Burghart
This room once housed a laboratory where water quality analyses were made. Today, it is the History Room, the first of three rooms that make up the Reflection Room exhibits. Here, you can take a journey through the scientific discoveries that led to the nuclear age and the historical events that made the Manhattan Project one of the most consequential events of the last century. The exhibits are intended to prompt personal thoughts and reflections.
Visit the History Room on our website for detailed pictures, exhibit text, and image descriptions.
Image Credit: NPS/Burghart
To fully fuel the reactor, workers loaded approximately 250 tons (7.25 mt) of uranium into the reactor. How did they load the equivalent weight of two average-sized blue whales of uranium into the reactor? Manhattan Project workers were adept at developing new tools and solutions needed to produce plutonium on an industrial scale for the very first time.
One such tool was the front face elevator that moved up and down the face of the reactor for the operators to charge (load) new fuel into the reactor while discharging irradiated fuel out the back of the reactor. There are two charging machines used to air pressure to push fuel into the process tubes. To unload the fuel/discharge reactor, workers, using an identical elevator on the rear face, removed the caps from the process tubes at the back of the reactor. Then they removed the caps on the front of the reactor and pushed fresh fuel into the front of the process tubes forcing spent fuel out the back of the reactor. Spent fuel fell into a 20 foot (6 m) deep pool of water and was stored there to allow the short-lived radioisotopes to decay and much of the heat to dissipate.
Image Credit: US Department of Energy
With more than 5,000 instruments to monitor, there was little downtime for control room workers. A wall of 2,004 Panellit gauges, named after the company that manufactured them, measured water flow through each of the 2,004 process tubes was just one set of instruments workers monitored during their shifts.
Workers recorded the pressure from each of the Panellit gauges. In an eight-hour shift, the crew would read one-third of the gauges and enter the data on paper. A sensing line ran from the inlet end of each process tube, just downstream of the orifice that controlled the flow of water, to the Panellit pressure gauges and switches in the control room. Two magnets on the dial were positioned for high and low trips. During initial use, small variations in pressure caused several accidental scrams, a fast shutdown of the pile, most often because the gauges were not properly dampened.
In fact, a worker just bumping against the Panellit board might cause any one of the gauges to trigger a scram. Additional operating experience showed sufficient protection was obtained by bypassing the safety circuit and having only an alarm sound when any of the 2,004 switches opened. After gaining yet more experience with the system of Panellit gauges, they were once again added as an input to the safety circuit.
Image Credit: US Department of Energy
World War II was the most deadly and destructive war in history. An estimated 70 to 85 million people died as a result of direct warfare, the Holocaust, and war-related disease and famine*.
Today, the populations of the capital cities of the major players in World War II—Beijing, Berlin, London, Moscow, Paris, Rome, Tokyo, and Washington D.C.— totals approximately 80 million.
Established in the context of World War II, the Manhattan Project created an extremely powerful and deadly weapon. The nuclear technology that developed from the Manhattan Project resulted in unforeseen outcomes and lasting legacies.
Write a postcard to citizens of the world in the year 2145, 200 years after the end of World War II. Share with them—your future family, teachers, world leaders—advice, hopes, and fears from your life experience living in the post-World War II world and the nuclear age.
* Estimates range from 50 to 55 million military and civilian deaths directly caused by warfare, the Holocaust, and other crimes against humanity. An additional estimated 19 to 28 million deaths resulted from war-related disease and famine. Worldwide casualty estimates vary widely among sources.
Image Credit: See exhibit panel for specific image credits