Manhattan Project National Historical Park Overview

Home , B Reactor, Calutron, Clinton Engineer Works, Fat Man, Little Boy, Louis Slotin

Interpretive Themes

NATIONAL PARK SERVICE • U.S. DEPARTMENT OF THE INTERIOR Interpretive themes are often described as the key stories or concepts that visitors should understand after visiting a park—they define the most important ideas or concepts communicated to visitors about a park unit. Themes Foundation Document Overview are derived from—and should reflect—park purpose, Manhattan Project National Historical Park significance, resources, and values. The set of interpretive themes is complete when it provides the structure necessary New Mexico, Tennessee, Washington for park staff to develop opportunities for visitors to explore and relate to all of the park significances and fundamental resources and values.

• The “secret cities” created for the Manhattan Project, and the sacrifice and displacement connected to them, exemplified this massive wartime effort and demonstrate remarkable opportunities to reflect on the extraordinary lengths to which people and nations go to protect their futures.

• The revolutionary science and engineering that fueled the race to create the world’s first atomic weapon make these places a powerful illustration of technological innovation and collaboration, and offer guidance and insight into solving today’s complex problems.

• From beginning to end, the Manhattan Project, its World War II context, and the many complex decisions that led to the incomprehensible destructive power of nuclear weapons prompts us to confront the profound choices and consequences that the world continues to struggle with today.

• The Manhattan Project thrust humanity into the nuclear age and forever changed the world, provoking consideration of dramatic scientific and technological advances as well as severe human costs and environmental consequences.

Contact Information For more information about the Manhattan Project National Historical Park Foundation Document, contact: [email protected] or write to: Superintendent, Manhattan Project National Historical Park, P.O. Box 25287, Denver, CO 80225-0287 FundamentalDescription Resources and Values

FundamentalEstablished on resources November and 10, values 2015, are Manhattan those features, Project systems, • Y-12 Plant Buildings 9731 and 9204-3. The electromagnetic • Gun Site Buildings. The Gun Site area of Los Alamos Hanford,• Hanford Washington High School. Hanford High School was a processes,National Historical experiences, Park stories, preserves, scenes, interprets, sounds, and smells, facilitates or separation method for uranium enrichment was pioneered was used during World War II to test the gun-type focal point of the pre-Manhattan Project community The Hanford Engineer Works produced plutonium on otheraccess attributes to key historic determined resources to merit associated primary with consideration the at industrial scale in Buildings 9731 and 9204-3 at the Y-12 weapon designs known as “Thin Man” and “Little Boy.” of Hanford, Washington. The school was vacated when an industrial scale. Its isolated location offered a margin duringManhattan planning Project. and The management Manhattan processes Project wasbecause a massive, they are National Security Complex, and these buildings produced Gun Site buildings consist of three concrete, earth- the town of Hanford was condemned for the Manhattan the final highly enriched uranium used in the “Little Boy” of safety given the dangerous nature of its activities and essentialtop-secret to national achieving mobilization the purpose of of scientists, the park andengineers, maintaining covered bunkers (Laboratory and Shop [TA-8-1], Shop Project, and was used for a short time as office space. Only bomb. Building 9731 was the first building constructed at the and Storage [TA-8-2], Diesel Generator Building [TA-8- the nearbythe outer Columbia shell of Riverthe original provided structure cooling remains water for intact. its itstechnicians, significance. and military personnel charged with producing Y-12 site, and contains the world’s only three alpha calutron 3]) and a portable guard shack (TA-8-172). Components powerfulThe current nuclear property reactors. withinJust 18 the months park afteralso includes the start aof small a deployable atomic weapon during World War II. It resulted Oak Ridge, Tennessee magnets as well as three beta calutron magnets. These of “Little Boy” were also assembled at the Gun Site construction,portion of Hanford the Hanford had produced Construction the plutonium Camp, where used more in in the first successful test of an atomic device on July 16, 1945, calutrons were used as test beds for the rest of the Y-12 before being shipped to the Pacific. the Trinitythan 50,000 Test and workers the “Fat lived Man” in tents implosion-type and barracks bomb. during The the •a fewK-25 weeks Building before Site. the United The gaseous States diffusiondropped atomic method bombs for complex. Building 9204-3 contains the last two remaining parkconstruction includes the Bof Reactor the Hanford National Engineer Historic Works. Landmark, uranium enrichment was pioneered at an industrial scale at Beta racetracks in America. One of these racetracks was in on Hiroshima and Nagasaki, Japan. Coordinated by the U.S. • V-Site. The V-Site buildings include the Assembly as well as the pre-war Hanford High School, Bruggemann’s Army,the ManhattanK-25 building. Project Built activities in March took 1945, place the inmammoth numerous 44- use as recently as 1998 for the separation of stable isotopes, OakBuilding Ridge, (HighTennessee Bay) (TA-16-516) and Workshop (TA-16- • White Bluffs Bank. The White Bluffs Bank building is acre building produced enriched uranium feed material for Agricultural Warehouse, White Bluffs Bank, and Hanford locations across the United States. The park is managed and remains on standby for potential future use. The Clinton517), and Engineer were constructed Works in Oakto support Ridge, theTennessee, assembly of the the only remaining structure of the pre-Manhattan Project the Y-12 electromagnetic separators for further enrichment, Irrigation District Pump House, which together provide through a collaborative partnership by the National Park servedplutonium as the administrative implosion-type headquarters bomb. They for were the alsoManhattan used to community of White Bluffs, Washington. When first including some of the uranium used in the “Little Boy” Los Alamos, New Mexico perspective on the sacrifices made for the Manhattan Project. Service and the U.S. Department of Energy, and incorporates Projectassemble and also the produced high-explosives the enriched sphere uranium for the Trinity used in device, constructed, it was claimed to be robbery-proof, though weapon that was dropped on Hiroshima. The U-shaped • Pond Cabin (TA-18-29). The Pond Cabin (TA-18-29), a the “Littleknown Boy” as the gun-type Gadget. bomb. V-Site Enrichment buildings in increasesuse during the the it was robbed twice in its operating history due to an threebuilding, of the Manhattanwhich measured Project’s a half-mile most significant long and 1,000locations: feet Visitor Access log structure, was built in 1914 by settler Ashley Pond and concentrationwar also included of the fissile several uranium-235 storage and isotope shop buildings to a level that easily breached wooden roof. The bank building, a small Oakwide, Ridge, continued Tennessee; to produce Los Alamos, highly New enriched Mexico; uranium and used supported Emilio Segrè’s plutonium fission research. The suitablewere for destroyed weapons by use. the Due Cerro to wartime Grande Fireurgency, in May scientists of 2000. The 25-footNational by Park 30-foot Service single-story and Department concrete of block Energy structure, will Hanford,in thermonuclear Washington. weapons during the Cold War until Pond Cabin is at the Pajarito Site, in Pajarito Canyon, on at OakThe Ridge V-Site developed was located multiple well away processes from forother uranium facilities at workis with currently American undergoing Indian Tribes,a comprehensive descendants rehabilitation of displaced production ceased in 1964. The K-25 building has since the Los Alamos National Laboratory grounds. The unprecedented scientific and industrial activities of enrichment,Los Alamos, and severalfor safety sites as andwell structures as security that reasons. supported communityto replicate members, the period other appearance organizations, and and facilitate members been demolished, and its footprint will remain undeveloped. these processes are incorporated into the park. These include public visitation. the Manhattan Project displaced many communities with • Battleship Bunker (TA-18-2). The Battleship Control of the general public who are interested in the park’s buildingsHanford, 9731 Washington and 9204-3, which housed large arrays or development. Due to ongoing national security requirements •thousands X-10 Graphite of people Reactor. to make The way world’sfor the rapidfirst constructioncontinuously Building was constructed to support implosion diagnostic • Bruggemann’s Agricultural Complex Warehouse. “racetracks” of calutrons that separated uranium isotopes of Manhattanoperating nuclear Project reactor, the X-10 Graphite Reactor tests for the plutonium implosion-type bomb design. A • B Reactor. The B Reactor is the first full-scale production and cleanupLocated activities, within two some miles sites of theincluded B Reactor, in the the park warehouse are with electromagnets, as well as the site of the enormous infrastructure.produced the first significant amounts of plutonium ever cast-in-place concrete bunker, it is known as the “battleship nuclear reactor in the world. Together with the D and F not currentlybuilding ataccessible Bruggemann’s to the generalAgricultural public, Complex and other is the park only K-25 plant (since demolished) which separated uranium In additionmade and to served its as a proof of concept for the B Reactor building” because the west end of the building is shaped like Reactors, the B Reactor produced the plutonium used sites remainingare accessible structure only via on organized the approximately bus tours. 530-acre Other sites farm MANHATTAN PROJECT NATIONALa bow of a HISTORICALship, shielded with PARKa steel plate. This Battleship isotopes using gaseous diffusion. Oak Ridge is also home at Hanford. The engineered reactor is a “pile” of graphite in the Trinity Test and the “Fat Man” bomb dropped on remainproperty eligible that for wasinclusion condemned in the park, by the but federal have government.not yet been industrial plants, to the X-10 Graphite Reactor National Historic Landmark, blocks measuring 24 feet per side, penetratedHanford by horizontal Control Building is at the Pajarito Site, in Pajarito Canyon, Nagasaki, Japan. The reactor’s core consists of a “pile” the U.S. government Washington added.The As structure part of their is part ongoing of one collaboration, of the few intact the independent National air-cooled channels that contained the uranium fuel slugs. on the Los Alamos National Laboratory grounds. the world’sof graphite first blocks continuously which held operating uranium nuclear fuel slugs reactor and that built large residential Parkfarming Service operationsand the Department representing of Energy the pre-Manhattan will endeavor Project The graphite blocks served as a neutron moderator, which demonstratedserved as athe neutron production moderator, of plutonium sustaining in pilota nuclear scale. chain neighborhoods to ! • Slotin Building (TA-18-1). The Slotin Building was to developera in theinnovative Northwest. and Thevirtual warehouse approaches itself to isconnect a unique helped to sustain a nuclear chain reaction. Designed and reaction. B Reactor is a national historic landmark and is constructed at the end of the Manhattan Project. It was the parkstructure visitors with constructed key resources, of Columbia as they Riverwork tocobblestone expand safe supportbuilt inthe less tens than of 10 months, it went into operation on Los accessibleAlamos, viaNew guided Mexico tours. Also located on the B Reactor location of the criticality accident that led to the death of physicalplaced access into to a concretethem. matrix. While the facility itself is thousandsNovember of workers 4, 1943. After the war, X-10 was used for a wide scientist Louis Slotin. The accident significantly influenced The Manhattangrounds are Project two locomotives established and a laboratory two cask at cars, remote part Los behind a fence awaiting stabilization and improvements, whovariety moved of to scientific these sites purposes, including the production of future criticality safety programs. The building remained Alamosof the to fosterrail system collaboration that hauled among irradiated prominent fuel rods scientists, from visitors can walk around it on existing roads. to supportradioisotopes, the project. until being shut down in 1963. Today, the in use during the Cold War. The Slotin Building is at engineers,Hanford’s technicians, reactors and to the support storage personnel and chemical in the separation design In thesereactor isolated, face and fenced control room are accessible to the public. the Pajarito Site, in Pajarito Canyon, on the Los Alamos and fabricationbuildings for of processing.the first nuclear weapons. The park includes • Hanford Irrigation District Pump House. The andThe gated reactor “secret” building cities, is a national historic landmark. Los AlamosNational Laboratory grounds. Oak Ridge structures located at three sites on the grounds of present-day Hanford Irrigation District Pump House, also known New Mexico Tennessee access and activities Los Alamos National Laboratory. Pajarito Site includes the as the “Allard” Pump House, was built by the Hanford Irrigation and Power Company to raise water more than were tightly monitored. ! ! Battleship Bunker, the Slotin Building, and the Pond Cabin, all Work on the sites was of which supported implosion testing and criticality research. 50 feet to a 36-mile irrigation network for farms in the V-Site consists of two buildings used to assemble the high- Priest Rapids Valley. When completed, area newspapers compartmentalized in explosives sphere for the “Gadget” detonated at the Trinity Test called the project “the largest pumping plant in the the name of security, with and to support the assembly of the “Fat Man” bomb, both of world.” The project enabled large scale farming and the majority unaware which used the implosion method and a plutonium core. Gun orchards in the area, which in turn supported individual that they were part of Site contains three bunkered buildings and a portable guard farms and community business in the towns of Hanford North developing the world’s 0 700 Kilometers shack. The site supported the development and final assembly and White Bluffs. The building shell and roof of the pump first nuclear weapons. 0 700 Miles of the “Little Boy” uranium bomb, which used the “gun” house are intact. method as opposed to implosion. Purpose Significance

Significance statements express why Manhattan Project • Initially identified as the primary location for the Manhattan National Historical Park resources and values are important Project, the Oak Ridge Reservation eventually produced enough to merit national park unit designation. Statements of enriched uranium and housed the management of the significance describe why an area is important within a global, nationwide project. Three revolutionary enrichment national, regional, and systemwide context. These statements processes were developed and implemented simultaneously are linked to the purpose of the park unit, and are supported by at the reservation, where thousands worked in cavernous data, research, and consensus. Significance statements describe industrial facilities to produce incremental amounts of the distinctive nature of the park and inform management weapons-grade uranium. Oak Ridge provided the fissile decisions, focusing efforts on preserving and protecting the material for the “Little Boy” atomic weapon dropped on most important resources and values of the park unit. Hiroshima, Japan, on August 6, 1945. • The wartime urgency surrounding the Manhattan Project • The Manhattan Project was an unprecedented, top-secret • Los Alamos became the location where world-renowned led to the displacement of generations-old settlements and World War II government program in which the United scientists and engineers led by J. Robert Oppenheimer tribal communities as many people were forced to sacrifice Managed in partnership by the States rushed to develop and deploy atomic weapons gathered in laboratories to design and develop the homes, lands and waters, sacred sites, and the access to Department of Energy and the National before Nazi Germany. The use of these weapons by the world’s first atomic weapons. Merely 26 months after the sacred sites to make way for covert military industrial sites United States against Japan in August 1945 ultimately start of the project, the Los Alamos team conducted the first Park Service, Manhattan Project and communities. became one of the most important historical events of the successful nuclear test at the Trinity Site in southern New national historical Park preserves and 20th century. Mexico on July 16, 1945, and assembled the two atomic interprets the nationally significant • The two atomic weapons used by the United States weapons the United States dropped on Japan in August 1945. on the Japanese cities of Hiroshima and Nagasaki historic sites, stories, and legacies • During the Manhattan Project, the U.S. Army directly unleashed an enormous and unprecedented amount or indirectly employed nearly 600,000 workers and • At a massive industrial complex at Hanford, Washington, associated with the top-secret race to of death and devastation for an individual weapon. An some of the world’s leading scientists at more than 30 the United States engineered and built the world’s first full- develop an atomic weapon during World estimated 90,000–166,000 people were killed or died sites nationwide, including three primary centers of scale nuclear reactor, uranium fuel fabrication facilities, War II, and provides access to these within months after the United States bombed Hiroshima operations established at Oak Ridge, Tennessee; Los and plutonium separation plant in only 18 months. using the “Little Boy” uranium bomb on August 6, 1945. sites consistent with the mission of the Alamos, New Mexico; and Hanford, Washington. This Hanford’s facilities produced the plutonium used in the An estimated 60,000–80,000 people were killed or died Department of Energy. effort channeled revolutionary scientific and engineering first successful test of a nuclear device at Trinity Site, and within months after the United States bombed Nagasaki innovations into an entirely new kind of weapon, the “Fat Man” plutonium bomb dropped on Nagasaki, using the “Fat Man” plutonium bomb three days later. ushering in the nuclear age. Japan, on August 9, 1945. • The colossal destructive power of nuclear weapons became a fundamental dynamic of the ensuing Cold War between the United States and the Soviet Union, a concept commonly referred to as deterrence through Mutual Assured Destruction, and spurred other nations to develop nuclear weapons of their own.

• The development and production of nuclear weapons in the United States and around the world has had profound consequences for human health and the environment, from radiation exposure from the use and testing of nuclear weapons to the chemical and radiological waste that remains from decades of nuclear weapons development.

• Scientific and technological advances made during the Manhattan Project in the pursuit of nuclear weapons contributed to progress in many areas, such as environmental and materials science, biology, nuclear medicine, nuclear energy, the nuclear Navy, supercomputing, precision machining, astronomy, and the Department of Energy’s National Laboratory System. FundamentalDescription Resources and Values

EstablishedFundamental on resources November and 10, values 2015, are Manhattan those features, Project systems, • Y-12 Plant Buildings 9731 and 9204-3. The electromagnetic • Gun Site Buildings. The Gun Site area of Los Alamos Hanford,• Hanford Washington High School. Hanford High School was a Nationalprocesses, Historical experiences, Park stories, preserves, scenes, interprets, sounds, and smells, facilitates or separation method for uranium enrichment was pioneered was used during World War II to test the gun-type focal point of the pre-Manhattan Project community The Hanford Engineer Works produced plutonium on accessother attributesto key historic determined resources to meritassociated primary with consideration the at industrial scale in Buildings 9731 and 9204-3 at the Y-12 weapon designs known as “Thin Man” and “Little Boy.” of Hanford, Washington. The school was vacated when an industrial scale. Its isolated location offered a margin Manhattanduring planning Project. and The management Manhattan processes Project was because a massive, they are National Security Complex, and these buildings produced Gun Site buildings consist of three concrete, earth- the town of Hanford was condemned for the Manhattan the final highly enriched uranium used in the “Little Boy” of safety given the dangerous nature of its activities and top-secretessential to national achieving mobilization the purpose of of scientists, the park engineers,and maintaining covered bunkers (Laboratory and Shop [TA-8-1], Shop Project, and was used for a short time as office space. Only bomb. Building 9731 was the first building constructed at the and Storage [TA-8-2], Diesel Generator Building [TA-8- the nearbythe outer Columbia shell of theRiver original provided structure cooling remains water forintact. its technicians,its significance. and military personnel charged with producing Y-12 site, and contains the world’s only three alpha calutron 3]) and a portable guard shack (TA-8-172). Components powerfulThe current nuclear property reactors. within Just 18 the months park also after includes the start a of small a deployable atomic weapon during World War II. It resulted Oak Ridge, Tennessee magnets as well as three beta calutron magnets. These of “Little Boy” were also assembled at the Gun Site construction,portion of Hanford the Hanford had producedConstruction the plutoniumCamp, where used more in in the first successful test of an atomic device on July 16, 1945, calutrons were used as test beds for the rest of the Y-12 before being shipped to the Pacific. the Trinitythan 50,000 Test and workers the “Fat lived Man” in tents implosion-type and barracks bomb. during The the a• fewK-25 weeks Building before theSite. United The gaseous States dropped diffusion atomic method bombs for complex. Building 9204-3 contains the last two remaining parkconstruction includes the of B Reactorthe Hanford National Engineer Historic Works. Landmark, uranium enrichment was pioneered at an industrial scale at Beta racetracks in America. One of these racetracks was in on Hiroshima and Nagasaki, Japan. Coordinated by the U.S. • V-Site. The V-Site buildings include the Assembly as well as the pre-war Hanford High School, Bruggemann’s Army,the Manhattan K-25 building. Project Built activities in March took 1945, place the in mammoth numerous 44- use as recently as 1998 for the separation of stable isotopes, OakBuilding Ridge, (High Tennessee Bay) (TA-16-516) and Workshop (TA-16- • White Bluffs Bank. The White Bluffs Bank building is acre building produced enriched uranium feed material for Agricultural Warehouse, White Bluffs Bank, and Hanford locations across the United States. The park is managed and remains on standby for potential future use. The517), Clinton and Engineer were constructed Works in toOak support Ridge, the Tennessee, assembly of the the only remaining structure of the pre-Manhattan Project the Y-12 electromagnetic separators for further enrichment, Irrigation District Pump House, which together provide through a collaborative partnership by the National Park servedplutonium as the administrative implosion-type headquarters bomb. They for were the also Manhattan used to community of White Bluffs, Washington. When first including some of the uranium used in the “Little Boy” Los Alamos, New Mexico perspective on the sacrifices made for the Manhattan Project. Service and the U.S. Department of Energy, and incorporates Projectassemble and also the produced high-explosives the enriched sphere uranium for the Trinity used in device, constructed, it was claimed to be robbery-proof, though weapon that was dropped on Hiroshima. The U-shaped • Pond Cabin (TA-18-29). The Pond Cabin (TA-18-29), a the “Littleknown Boy” as the gun-type Gadget. bomb.V-Site Enrichmentbuildings in useincreases during the the it was robbed twice in its operating history due to an threebuilding, of the Manhattan which measured Project’s a half-mile most significant long and locations:1,000 feet Visitor Access log structure, was built in 1914 by settler Ashley Pond and concentrationwar also included of the fissile several uranium-235 storage and shopisotope buildings to a level that easily breached wooden roof. The bank building, a small Oakwide, Ridge, continued Tennessee; to Losproduce Alamos, highly New enriched Mexico; uranium and used supported Emilio Segrè’s plutonium fission research. The suitablewere for destroyed weapons by use. the Due Cerro to Grandewartime Fire urgency, in May scientists of 2000. The25-foot National by Park 30-foot Service single-story and Department concrete ofblock Energy structure, will Hanford,in thermonuclear Washington. weapons during the Cold War until Pond Cabin is at the Pajarito Site, in Pajarito Canyon, on at OakThe Ridge V-Site developed was located multiple well away processes from other for uranium facilities at workis withcurrently American undergoing Indian aTribes, comprehensive descendants rehabilitation of displaced production ceased in 1964. The K-25 building has since the Los Alamos National Laboratory grounds. The unprecedented scientific and industrial activities of enrichment,Los Alamos, and forseveral safety sites as welland structuresas security thatreasons. supported communityto replicate members, the period other appearance organizations, and facilitateand members been demolished, and its footprint will remain undeveloped. these processes are incorporated into the park. These include public visitation. the Manhattan Project displaced many communities with • Battleship Bunker (TA-18-2). The Battleship Control of the general public who are interested in the park’s buildingsHanford, 9731 Washington and 9204-3, which housed large arrays or development. Due to ongoing national security requirements thousands• X-10 Graphite of people Reactor. to make wayThe forworld’s the rapid first constructioncontinuously Building was constructed to support implosion diagnostic • Bruggemann’s Agricultural Complex Warehouse. “racetracks” of calutrons that separated uranium isotopes of Manhattanoperating nuclear Project reactor, the X-10 Graphite Reactor tests for the plutonium implosion-type bomb design. A • B Reactor. The B Reactor is the first full-scale production andLocated cleanup withinactivities, two some miles sites of the included B Reactor, in the the park warehouse are with electromagnets, as well as the site of the enormous infrastructure.produced the first significant amounts of plutonium ever cast-in-place concrete bunker, it is known as the “battleship nuclear reactor in the world. Together with the D and F not buildingcurrently at accessible Bruggemann’s to the Agricultural general public, Complex and other is the park only K-25 plant (since demolished) which separated uranium In additionmade and to servedits as a proof of concept for the B Reactor building” because the west end of the building is shaped like Reactors, the B Reactor produced the plutonium used sitesremaining are accessible structure only viaon organizedthe approximately bus tours. 530-acre Other sites farm MANHATTAN PROJECT NATIONALa bow of aHISTORICAL ship, shielded with PARK a steel plate. This Battleship isotopes using gaseous diffusion. Oak Ridge is also home at Hanford. The engineered reactor is a “pile” of graphite in the Trinity Test and the “Fat Man” bomb dropped on remainproperty eligible that for was inclusion condemned in the bypark, the but federal have government. not yet been industrial plants, to the X-10 Graphite Reactor National Historic Landmark, blocks measuring 24 feet per side, penetratedHanford by horizontal Control Building is at the Pajarito Site, in Pajarito Canyon, Nagasaki, Japan. The reactor’s core consists of a “pile” the U.S. government Washington added.The As structure part of theiris part ongoing of one collaboration,of the few intact the independent National air-cooled channels that contained the uranium fuel slugs. on the Los Alamos National Laboratory grounds. the world’sof graphite first blocks continuously which held operating uranium nuclear fuel slugs reactor and that built large residential Parkfarming Service operations and the Department representing of Energythe pre-Manhattan will endeavor Project The graphite blocks served as a neutron moderator, which demonstratedserved as a the neutron production moderator, of plutonium sustaining in apilot nuclear scale. chain neighborhoods to ! • Slotin Building (TA-18-1). The Slotin Building was to developera in the innovative Northwest. and The virtual warehouse approaches itself to is connect a unique helped to sustain a nuclear chain reaction. Designed and reaction. B Reactor is a national historic landmark and is constructed at the end of the Manhattan Project. It was the parkstructure visitors with constructed key resources, of Columbia as they River work cobblestone to expand safe supportbuilt thein less tens than of 10 months, it went into operation on Losaccessible Alamos, via New guided Mexico tours. Also located on the B Reactor location of the criticality accident that led to the death of physicalplaced access into toa concrete them. matrix. While the facility itself is thousandsNovember of workers 4, 1943. After the war, X-10 was used for a wide scientist Louis Slotin. The accident significantly influenced Thegrounds Manhattan are Projecttwo locomotives established and a laboratory two cask cars,at remote part Los behind a fence awaiting stabilization and improvements, whovariety moved of to scientific these sites purposes, including the production of future criticality safety programs. The building remained Alamosof the to railfoster system collaboration that hauled among irradiated prominent fuel rods scientists, from visitors can walk around it on existing roads. to supportradioisotopes, the project. until being shut down in 1963. Today, the in use during the Cold War. The Slotin Building is at engineers,Hanford’s technicians, reactors toand the support storage personnel and chemical in the separation design In thesereactor isolated, face and fenced control room are accessible to the public. the Pajarito Site, in Pajarito Canyon, on the Los Alamos and buildingsfabrication for of processing. the first nuclear weapons. The park includes • Hanford Irrigation District Pump House. The andThe gated reactor “secret” building cities, is a national historic landmark. Los AlamosNational Laboratory grounds. Oak Ridge structures located at three sites on the grounds of present-day Hanford Irrigation District Pump House, also known New Mexico Tennessee access and activities Los Alamos National Laboratory. Pajarito Site includes the as the “Allard” Pump House, was built by the Hanford Irrigation and Power Company to raise water more than were tightly monitored. ! ! Battleship Bunker, the Slotin Building, and the Pond Cabin, all Work on the sites was of which supported implosion testing and criticality research. 50 feet to a 36-mile irrigation network for farms in the V-Site consists of two buildings used to assemble the high- Priest Rapids Valley. When completed, area newspapers compartmentalized in explosives sphere for the “Gadget” detonated at the Trinity Test called the project “the largest pumping plant in the the name of security, with and to support the assembly of the “Fat Man” bomb, both of world.” The project enabled large scale farming and the majority unaware which used the implosion method and a plutonium core. Gun orchards in the area, which in turn supported individual that they were part of Site contains three bunkered buildings and a portable guard farms and community business in the towns of Hanford North developing the world’s 0 700 Kilometers shack. The site supported the development and final assembly and White Bluffs. The building shell and roof of the pump first nuclear weapons. 0 700 Miles of the “Little Boy” uranium bomb, which used the “gun” house are intact. method as opposed to implosion. Interpretive Themes