B-Reactor
Encyclopedia
The B Reactor at the Hanford Site
, near Richland, Washington
, USA, was the first large-scale nuclear reactor
ever built. The project was commissioned to produce plutonium-239
by nuclear fission
as part of the Manhattan Project
, the United States nuclear weapons
development program during World War II
. The B reactor was fueled with metallic natural uranium
, graphite moderated
, and water-cooled. It has been designated a U.S. National Historic Landmark
since August 19, 2008 and in July of 2011 the National Park Service recommended that the B Reactor be included in a national historic park commemorating the Manhattan Project.
based on experimental designs tested by Enrico Fermi
at the University of Chicago
, and tests from the X-10 Graphite Reactor
at Oak Ridge National Laboratory
. It was designed to operate at 250 megawatts.
The reactor occupies a footprint of 46 by (about 1750 sq ft (162.6 m²) and is 41 ft (12.5 m) (approximately five stories) tall, occupying a volume of 71500 cu ft (2,024.7 m³).
The reactor core
itself consisted of a 36 feet (11 m) graphite box measuring 28 by occupying a volume of 1000 cu ft (28.3 m³) and weighing 1200 ST (1,071.4 LT). It was penetrated horizontally through its entire length by 2,004 aluminum tubes and vertically by channels for the "vertical safety rods," .
The core is surrounded by a thermal shield
of cast iron
8 to 10 in (20.3 to 25.4 cm) thick weighing 1000 ST (892.9 LT). Masonite and steel plates enclose the thermal shield on its top and sides, forming a biological shield for radiation protection. The bottom of the thermal shield is supported by a 23 feet (7 m) concrete pad topped by cast-iron blocks.
The graphite
composition was selected to moderate
the nuclear reaction
fueled by 200 ST (178.6 LT) of uranium
slugs approximately 25 mm (0.984251968503937 in) diameter 70 mm (3 in) long (the approximate size of a roll of quarter
s), sealed in aluminum cans, and loaded into the aluminum tubes.
The reactor was water-cooled, with cooling water pumped from the Hanford Reach
of the Columbia River
through the aluminum tubes around the uranium slugs at the rate of 75000 US gal (283,905.9 l) per minute. The water was discharged into settling basins, then returned to the river after allowing time for the decay of radioactive materials
and the settling out of particulate matter.
in September, 1944, the D Reactor in December 1944 and the F Reactor in February 1945. The reactor produced plutonium-239
by irradiating uranium-238
with neutron
s generated by the nuclear reaction. It was one of three reactors — along with the D and F reactors — built about six miles (10 km) apart on the south bank of the Columbia River. Each reactor had its own auxiliary facilities that included a river pump house, large storage and settling basins, a filtration plant, large motor-driven pumps for delivering water to the face of the pile, and facilities for emergency cooling in case of a power failure.
Emergency shutdown of the reactor, referred to as a SCRAM
, was attained either by rapidly fully inserting the vertical safety rods (now called control rods) or, as a backup method, by the injection of borated water
into the reactor. In January 1952, the borated water system was replaced by a "Ball-3X" system that injected nickel
-plated high-boron
steel balls into the channels occupied by the vertical safety rods.
The plutonium for the nuclear bomb used in the Trinity test at Los Alamos
in New Mexico
and the Fat Man
bomb dropped on Nagasaki, Japan
was created in the B, D, and F reactors. These first three reactors ran for two decades, and were joined by additional reactors constructed later. The B Reactor was permanently shut down in February 1968.
, the reactor buildings are demolished up to the 4 feet (1.2 m) concrete
shield around the reactor core. Any openings are sealed and a new roof is built. The D and F reactors have already been entombed, as have the C and DR reactors. Most auxiliary buildings at the first three reactors have been demolished, as well. The H, K-East and K-West reactors and the N-Reactor
are scheduled to be entombed in that order.
The United States Department of Energy
has administered the site since 1977 and offers public tours on set dates during the spring, summer, and fall of the year, as well as special tours for visiting officials. The B Reactor was added to the National Register of Historic Places
(#) on April 3, 1992, and was named a National Historic Landmark
on August 19, 2008. It is in the process of conversion into a museum
.
Hanford Site
The Hanford Site is a mostly decommissioned nuclear production complex on the Columbia River in the U.S. state of Washington, operated by the United States federal government. The site has been known by many names, including Hanford Works, Hanford Engineer Works or HEW, Hanford Nuclear Reservation...
, near Richland, Washington
Richland, Washington
Richland is a city in Benton County in the southeastern part of the U.S. state of Washington, at the confluence of the Yakima and the Columbia Rivers. As of the 2010 census, the city population was 48,058. April 1, 2011 estimates from the Washington State Office of Financial Management put the...
, USA, was the first large-scale nuclear reactor
Nuclear reactor
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...
ever built. The project was commissioned to produce plutonium-239
Plutonium-239
Plutonium-239 is an isotope of plutonium. Plutonium-239 is the primary fissile isotope used for the production of nuclear weapons, although uranium-235 has also been used and is currently the secondary isotope. Plutonium-239 is also one of the three main isotopes demonstrated usable as fuel in...
by nuclear fission
Nuclear fission
In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons , and releasing a tremendous amount of energy...
as part of the Manhattan Project
Manhattan Project
The Manhattan Project was a research and development program, led by the United States with participation from the United Kingdom and Canada, that produced the first atomic bomb during World War II. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the US Army...
, the United States nuclear weapons
Nuclear weapons and the United States
The United States was the first country to develop nuclear weapons, and is the only country to have used them in warfare, with the separate bombings of Hiroshima and Nagasaki in World War II. Before and during the Cold War it conducted over a thousand nuclear tests and developed many long-range...
development program during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. The B reactor was fueled with metallic natural uranium
Natural uranium
Natural uranium refers to refined uranium with the same isotopic ratio as found in nature. It contains 0.7 % uranium-235, 99.3 % uranium-238, and a trace of uranium-234 by weight. In terms of the amount of radioactivity, approximately 2.2 % comes from uranium-235, 48.6 % uranium-238, and 49.2 %...
, graphite moderated
Neutron moderator
In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235....
, and water-cooled. It has been designated a U.S. National Historic Landmark
National Historic Landmark
A National Historic Landmark is a building, site, structure, object, or district, that is officially recognized by the United States government for its historical significance...
since August 19, 2008 and in July of 2011 the National Park Service recommended that the B Reactor be included in a national historic park commemorating the Manhattan Project.
Reactor design and construction
The reactor was designed and built by E. I. du Pont de Nemours and CompanyDuPont
E. I. du Pont de Nemours and Company , commonly referred to as DuPont, is an American chemical company that was founded in July 1802 as a gunpowder mill by Eleuthère Irénée du Pont. DuPont was the world's third largest chemical company based on market capitalization and ninth based on revenue in 2009...
based on experimental designs tested by Enrico Fermi
Enrico Fermi
Enrico Fermi was an Italian-born, naturalized American physicist particularly known for his work on the development of the first nuclear reactor, Chicago Pile-1, and for his contributions to the development of quantum theory, nuclear and particle physics, and statistical mechanics...
at the University of Chicago
University of Chicago
The University of Chicago is a private research university in Chicago, Illinois, USA. It was founded by the American Baptist Education Society with a donation from oil magnate and philanthropist John D. Rockefeller and incorporated in 1890...
, and tests from the X-10 Graphite Reactor
X-10 Graphite Reactor
The X-10 Graphite Reactor at Oak Ridge National Laboratory in Oak Ridge, Tennessee, formerly known as the Clinton Pile and X-10 Pile, was the world's second artificial nuclear reactor and was the first reactor designed and built for continuous operation.When President Roosevelt in December 1942...
at Oak Ridge National Laboratory
Oak Ridge National Laboratory
Oak Ridge National Laboratory is a multiprogram science and technology national laboratory managed for the United States Department of Energy by UT-Battelle. ORNL is the DOE's largest science and energy laboratory. ORNL is located in Oak Ridge, Tennessee, near Knoxville...
. It was designed to operate at 250 megawatts.
The reactor occupies a footprint of 46 by (about 1750 sq ft (162.6 m²) and is 41 ft (12.5 m) (approximately five stories) tall, occupying a volume of 71500 cu ft (2,024.7 m³).
The reactor core
Nuclear reactor core
A nuclear reactor core is the portion of a nuclear reactor containing the nuclear fuel components where the nuclear reactions take place.- Description :...
itself consisted of a 36 feet (11 m) graphite box measuring 28 by occupying a volume of 1000 cu ft (28.3 m³) and weighing 1200 ST (1,071.4 LT). It was penetrated horizontally through its entire length by 2,004 aluminum tubes and vertically by channels for the "vertical safety rods," .
The core is surrounded by a thermal shield
Heat shield
A heat shield is designed to shield a substance from absorbing excessive heat from an outside source by either dissipating, reflecting or simply absorbing the heat...
of cast iron
Cast iron
Cast iron is derived from pig iron, and while it usually refers to gray iron, it also identifies a large group of ferrous alloys which solidify with a eutectic. The color of a fractured surface can be used to identify an alloy. White cast iron is named after its white surface when fractured, due...
8 to 10 in (20.3 to 25.4 cm) thick weighing 1000 ST (892.9 LT). Masonite and steel plates enclose the thermal shield on its top and sides, forming a biological shield for radiation protection. The bottom of the thermal shield is supported by a 23 feet (7 m) concrete pad topped by cast-iron blocks.
The graphite
Graphite
The mineral graphite is one of the allotropes of carbon. It was named by Abraham Gottlob Werner in 1789 from the Ancient Greek γράφω , "to draw/write", for its use in pencils, where it is commonly called lead . Unlike diamond , graphite is an electrical conductor, a semimetal...
composition was selected to moderate
Neutron moderator
In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235....
the nuclear reaction
Nuclear reaction
In nuclear physics and nuclear chemistry, a nuclear reaction is semantically considered to be the process in which two nuclei, or else a nucleus of an atom and a subatomic particle from outside the atom, collide to produce products different from the initial particles...
fueled by 200 ST (178.6 LT) of uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
slugs approximately 25 mm (0.984251968503937 in) diameter 70 mm (3 in) long (the approximate size of a roll of quarter
Quarter (United States coin)
A quarter dollar, commonly shortened to quarter, is a coin worth ¼ of a United States dollar, or 25 cents. The quarter has been produced since 1796. The choice of 25¢ as a denomination, as opposed to 20¢ which is more common in other parts of the world, originated with the practice of dividing...
s), sealed in aluminum cans, and loaded into the aluminum tubes.
The reactor was water-cooled, with cooling water pumped from the Hanford Reach
Hanford Reach
The Hanford Reach is a free-flowing section of the Columbia River, about long, in eastern Washington state, named after a large northward bend in the river's otherwise southbound course. It is the only section of the Columbia in the U.S...
of the Columbia River
Columbia River
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada, flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state...
through the aluminum tubes around the uranium slugs at the rate of 75000 US gal (283,905.9 l) per minute. The water was discharged into settling basins, then returned to the river after allowing time for the decay of radioactive materials
Radioactive decay
Radioactive decay is the process by which an atomic nucleus of an unstable atom loses energy by emitting ionizing particles . The emission is spontaneous, in that the atom decays without any physical interaction with another particle from outside the atom...
and the settling out of particulate matter.
Reactor operation
The B Reactor had its first nuclear chain reactionNuclear chain reaction
A nuclear chain reaction occurs when one nuclear reaction causes an average of one or more nuclear reactions, thus leading to a self-propagating number of these reactions. The specific nuclear reaction may be the fission of heavy isotopes or the fusion of light isotopes...
in September, 1944, the D Reactor in December 1944 and the F Reactor in February 1945. The reactor produced plutonium-239
Plutonium-239
Plutonium-239 is an isotope of plutonium. Plutonium-239 is the primary fissile isotope used for the production of nuclear weapons, although uranium-235 has also been used and is currently the secondary isotope. Plutonium-239 is also one of the three main isotopes demonstrated usable as fuel in...
by irradiating uranium-238
Uranium-238
Uranium-238 is the most common isotope of uranium found in nature. It is not fissile, but is a fertile material: it can capture a slow neutron and after two beta decays become fissile plutonium-239...
with neutron
Neutron
The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of...
s generated by the nuclear reaction. It was one of three reactors — along with the D and F reactors — built about six miles (10 km) apart on the south bank of the Columbia River. Each reactor had its own auxiliary facilities that included a river pump house, large storage and settling basins, a filtration plant, large motor-driven pumps for delivering water to the face of the pile, and facilities for emergency cooling in case of a power failure.
Emergency shutdown of the reactor, referred to as a SCRAM
Scram
A scram or SCRAM is an emergency shutdown of a nuclear reactor – though the term has been extended to cover shutdowns of other complex operations, such as server farms and even large model railroads...
, was attained either by rapidly fully inserting the vertical safety rods (now called control rods) or, as a backup method, by the injection of borated water
Borate
Borates are chemical compounds which contain oxoanions of boron in oxidation state +3. The simplest borate ion, BO33−, has a trigonal planar structure. Other borates are made up of trigonal BO3 or tetrahedral BO4 structural units, sharing oxygen atoms...
into the reactor. In January 1952, the borated water system was replaced by a "Ball-3X" system that injected nickel
Nickel
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...
-plated high-boron
Boron
Boron is the chemical element with atomic number 5 and the chemical symbol B. Boron is a metalloid. Because boron is not produced by stellar nucleosynthesis, it is a low-abundance element in both the solar system and the Earth's crust. However, boron is concentrated on Earth by the...
steel balls into the channels occupied by the vertical safety rods.
The plutonium for the nuclear bomb used in the Trinity test at Los Alamos
Los Alamos National Laboratory
Los Alamos National Laboratory is a United States Department of Energy national laboratory, managed and operated by Los Alamos National Security , located in Los Alamos, New Mexico...
in New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
and the Fat Man
Fat Man
"Fat Man" is the codename for the atomic bomb that was detonated over Nagasaki, Japan, by the United States on August 9, 1945. It was the second of the only two nuclear weapons to be used in warfare to date , and its detonation caused the third man-made nuclear explosion. The name also refers more...
bomb dropped on Nagasaki, Japan
Atomic bombings of Hiroshima and Nagasaki
During the final stages of World War II in 1945, the United States conducted two atomic bombings against the cities of Hiroshima and Nagasaki in Japan, the first on August 6, 1945, and the second on August 9, 1945. These two events are the only use of nuclear weapons in war to date.For six months...
was created in the B, D, and F reactors. These first three reactors ran for two decades, and were joined by additional reactors constructed later. The B Reactor was permanently shut down in February 1968.
Current status
B Reactor is now in "interim safe storage" status. The D and F reactors were shut down in June 1967 and June 1965, respectively. In a process called cocooning or entombmentNuclear entombment
Entombment of a nuclear reactor is a method of nuclear decommissioning in which radioactive contaminants are encased in a structurally long-lived material, such as concrete, that will last for a period of time to ensure the remaining radioactivity is no longer of significant concern...
, the reactor buildings are demolished up to the 4 feet (1.2 m) concrete
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
shield around the reactor core. Any openings are sealed and a new roof is built. The D and F reactors have already been entombed, as have the C and DR reactors. Most auxiliary buildings at the first three reactors have been demolished, as well. The H, K-East and K-West reactors and the N-Reactor
N-Reactor
The N-Reactor was a graphite-moderated nuclear reactor constructed during the Cold War and operated by the U.S. government at the Hanford Site in Washington....
are scheduled to be entombed in that order.
The United States Department of Energy
United States Department of Energy
The United States Department of Energy is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material...
has administered the site since 1977 and offers public tours on set dates during the spring, summer, and fall of the year, as well as special tours for visiting officials. The B Reactor was added to the National Register of Historic Places
National Register of Historic Places
The National Register of Historic Places is the United States government's official list of districts, sites, buildings, structures, and objects deemed worthy of preservation...
(#) on April 3, 1992, and was named a National Historic Landmark
National Historic Landmark
A National Historic Landmark is a building, site, structure, object, or district, that is officially recognized by the United States government for its historical significance...
on August 19, 2008. It is in the process of conversion into a museum
Museum
A museum is an institution that cares for a collection of artifacts and other objects of scientific, artistic, cultural, or historical importance and makes them available for public viewing through exhibits that may be permanent or temporary. Most large museums are located in major cities...
.
Timeline of major events
| Year | Date | Event |
|---|---|---|
| 1943 | October | U.S. Army Corps of Engineers breaks ground to build B Reactor |
| 1944 | September 13th | First Uranium fuel slug loaded into B Reactor |
| 1944 | September 26th | Initial reactor criticality achieved |
| 1945 | February 3rd | B Reactor Plutonium delivered to Los Alamos |
| 1945 | July 16th | B Reactor Plutonium used for first nuclear test explosion at Trinity Test Site in Alamagordo, New Mexico |
| 1945 | August 9th | B Reactor Plutonium used for "Fat Man Fat Man "Fat Man" is the codename for the atomic bomb that was detonated over Nagasaki, Japan, by the United States on August 9, 1945. It was the second of the only two nuclear weapons to be used in warfare to date , and its detonation caused the third man-made nuclear explosion. The name also refers more... " bomb dropped on Nagasaki, Japan |
| 1946 | March | B Reactor operations suspended |
| 1948 | June | B Reactor operation resumed |
| 1949 | March | B Reactor begins production of tritium for use in hydrogen bomb |
| 1952 | November 1st | B Reactor tritium used in first test detonation of a hydrogen bomb at Bikini Atoll Bikini Atoll Bikini Atoll is an atoll, listed as a World Heritage Site, in the Micronesian Islands of the Pacific Ocean, part of Republic of the Marshall Islands.... |
| 1968 | January 29th | Atomic Energy Commission directs shutdown of B Reactor |
| 1976 | Declared National Historic Mechanical Engineering Landmark by American Society of Mechanical Engineers American Society of Mechanical Engineers The American Society of Mechanical Engineers is a professional body, specifically an engineering society, focused on mechanical engineering.... |
|
| 2008 | Declared National Historic Landmark National Historic Landmark A National Historic Landmark is a building, site, structure, object, or district, that is officially recognized by the United States government for its historical significance... by U.S. Department of Interior and National Park Service National Park Service The National Park Service is the U.S. federal agency that manages all national parks, many national monuments, and other conservation and historical properties with various title designations... |
|
| 2009 | U.S. Department of Energy announces public tours | |
| 2011 | July | National Park Service recommends B Reactor be included in a national historic park commemorating the Manhattan Project. |
Sources
- Washington Closure Hanford -
- United States Department of Energy - B Reactor
- B Reactor a historic Landmark
External links
- B Reactor Museum Association A collection of Hanford-related documents from a group working to preserve the B-100 Reactor at Hanford.
- Reactor 105-B (museum) location: 46°37′49"N 119°38′51"W
- Hanford Site Tours - Department of Energy, includes B Reactor