X-10 Graphite Reactor
X-10 Graphite Reactor | ||
---|---|---|
fissile material) Metallic natural uranium | | |
Fuel state | Solid (pellets) | |
Neutron energy spectrum | slow | |
Primary control method | Control rods | |
Primary moderator | Nuclear graphite (bricks) | |
Primary coolant | Air | |
Reactor usage | ||
Primary use | Research | |
Remarks | The world's second artificial nuclear reactor. | |
X-10 Graphite Reactor | ||
Location | Oak Ridge National Laboratory | |
Nearest city | Oak Ridge, Tennessee | |
Coordinates | 35°55′41″N 84°19′3″W / 35.92806°N 84.31750°W | |
Area | less than 1-acre (0.40 ha)[1] | |
Built | 1943 | |
NRHP reference No. | 66000720 | |
Significant dates | ||
Added to NRHP | October 15, 1966 | |
Designated NHL | December 21, 1965 |
The X-10 Graphite Reactor is a decommissioned nuclear reactor at Oak Ridge National Laboratory in Oak Ridge, Tennessee. Formerly known as the Clinton Pile and X-10 Pile, it was the world's second artificial nuclear reactor (after Enrico Fermi's Chicago Pile-1), and the first designed and built for continuous operation. It was built during World War II as part of the Manhattan Project.
While Chicago Pile-1 demonstrated the feasibility of nuclear reactors, the Manhattan Project's goal of producing enough
Origins
The discovery of
In April 1941, the
The final draft of Compton's November 1941 report made no mention of using plutonium, but after discussing the latest research with Ernest Lawrence, Compton became convinced that a plutonium bomb was also feasible. In December, Compton was placed in charge of the plutonium project,[12] which was codenamed X-10.[13] Its objectives were to produce reactors to convert uranium to plutonium, to find ways to chemically separate the plutonium from the uranium, and to design and build an atomic bomb.[10][14] It fell to Compton to decide which of the different types of reactor designs the scientists should pursue, even though a successful reactor had not yet been built.[15] He felt that having teams at Columbia, Princeton, the University of Chicago and the University of California was creating too much duplication and not enough collaboration, and he concentrated the work at the Metallurgical Laboratory at the University of Chicago.[16]
Site selection
By June 1942, the Manhattan Project had reached the stage where the construction of production facilities could be contemplated. On June 25, 1942, the Office of Scientific Research and Development (OSRD) S-1 Executive Committee deliberated on where they should be located.[17] Moving directly to a megawatt production plant looked like a big step, given that many industrial processes do not easily scale from the laboratory to production size. An intermediate step of building a pilot plant was considered prudent.[18] For the pilot plutonium separation plant, a site was wanted close to the Metallurgical Laboratory, where the research was being carried out, but for reasons of safety and security, it was not desirable to locate the facilities in a densely populated area like Chicago.[17]
Compton selected a site in the
This site was selected on the basis of several criteria. The plutonium pilot facilities needed to be two to four miles (3.2 to 6.4 km) from the site boundary and any other installation, in case radioactive
In December, it was decided that the plutonium production facilities would not be built at Oak Ridge after all, but at the even more remote
Both Compton and Groves proposed that DuPont operate the semiworks. Williams counter-proposed that the semiworks be operated by the Metallurgical Laboratory. He reasoned that it would primarily be a research and educational facility, and that expertise was to be found at the Metallurgical Laboratory. Compton was shocked;[24] the Metallurgical Laboratory was part of the University of Chicago, and therefore the university would be operating an industrial facility 500 miles (800 km) from its main campus. James B. Conant told him that Harvard University "wouldn't touch it with a ten-foot pole",[25] but the University of Chicago's Vice President, Emery T. Filbey, took a different view, and instructed Compton to accept.[26] When University President Robert Hutchins returned, he greeted Compton with "I see, Arthur, that while I was gone you doubled the size of my university".[27]
Design
The fundamental design decisions in building a reactor are the choice of fuel, coolant and neutron moderator. The choice of fuel was straightforward; only natural uranium was available. The decision that the reactor would use graphite as a neutron moderator caused little debate. Although with heavy water as moderator the number of neutrons produced for every one absorbed (known as k factor) was 10 percent more than in the purest graphite, heavy water would be unavailable in sufficient quantities for at least a year.[28] This left the choice of coolant, over which there was much discussion. A limiting factor was that the fuel slugs would be clad in aluminum, so the operating temperature of the reactor could not exceed 200 °C (392 °F).[18] The theoretical physicists in Wigner's group at the Metallurgical Laboratory developed several designs. In November 1942, the DuPont engineers chose helium gas as the coolant for the production plant, mainly on the basis that it did not absorb neutrons, but also because it was inert, which removed the issue of corrosion.[29]
Not everyone agreed with the decision to use helium. Szilard, in particular, was an early proponent of using liquid bismuth; but the major opponent was Wigner, who argued forcefully in favor of a water-cooled reactor design. He realized that since water absorbed neutrons, k would be reduced by about 3 percent, but had sufficient confidence in his calculations that the water-cooled reactor would still be able to achieve criticality. From an engineering perspective, a water-cooled design was straightforward to design and build, while helium posed technological problems. Wigner's team produced a preliminary report on water cooling, designated CE-140 in April 1942, followed by a more detailed one, CE-197, titled "On a Plant with Water Cooling", in July 1942.[30]
Fermi's Chicago Pile-1 reactor, constructed under the west viewing stands of the original Stagg Field at the University of Chicago, "went critical" on December 2, 1942. This graphite-moderated reactor only generated up to 200 W, but it demonstrated that k was higher than anticipated. This not only removed most of the objections to air-cooled and water-cooled reactor designs, it greatly simplified other aspects of the design. Wigner's team submitted blueprints of a water-cooled reactor to DuPont in January 1943. By this time, the concerns of DuPont's engineers about the corrosiveness of water had been overcome by the mounting difficulties of using helium, and all work on helium was terminated in February. At the same time, air cooling was chosen for the reactor at the pilot plant.[31] Since it would be of a quite different design from the production reactors, the X-10 Graphite Reactor lost its value as a prototype, but its value as a working pilot facility remained, providing plutonium needed for research.[32] It was hoped that problems would be found in time to deal with them in the production plants. The semiworks would also be used for training, and for developing procedures.[18]
Construction
Although the design of the reactor was not yet complete, DuPont began construction of the plutonium semiworks on February 2, 1943,[33] on an isolated 112-acre (45.3 ha) site in the Bethel Valley about 10 miles (16 km) southwest of Oak Ridge officially known as the X-10 area. The site included research laboratories, a chemical separation plant, a waste storage area, a training facility for Hanford staff, and administrative and support facilities that included a laundry, cafeteria, first aid center, and fire station. Because of the subsequent decision to construct water-cooled reactors at Hanford, only the chemical separation plant operated as a true pilot.[34][35] The semiworks eventually became known as the Clinton Laboratories, and was operated by the University of Chicago as part of the Metallurgical Project.[36]
Construction work on the reactor had to wait until DuPont had completed the design. Excavation commenced on April 27, 1943. A large pocket of soft clay was soon discovered, necessitating additional foundations.[37] Further delays occurred due to wartime difficulties in procuring building materials. There was an acute shortage of both common and skilled labor; the contractor had only three-quarters of the required workforce, and there was high turnover and absenteeism, mainly the result of poor accommodations and difficulties in commuting. The township of Oak Ridge was still under construction, and barracks were built to house workers. Special arrangements with individual workers increased their morale and reduced turnover. Finally, there was unusually heavy rainfall, with 9.3 inches (240 mm) falling in July 1943, more than twice the average of 4.3 inches (110 mm).[34][38]
Some 700 short tons (640 t) of graphite blocks were purchased from National Carbon. The construction crews began stacking them in September 1943. Cast uranium billets came from Metal Hydrides, Mallinckrodt and other suppliers. These were extruded into cylindrical slugs, and then canned.[39] The fuel slugs were canned to protect the uranium metal from corrosion that would occur if it came into contact with water, and to prevent the venting of gaseous radioactive fission products that might be formed when they were irradiated. Aluminum was chosen as it transmitted heat well but did not absorb too many neutrons.[40] Alcoa started canning on June 14, 1943. General Electric and the Metallurgical Laboratory developed a new welding technique to seal the cans airtight, and the equipment for this was installed in the production line at Alcoa in October 1943.[39]
Construction commenced on the pilot separation plant before a chemical process for separating plutonium from uranium had been selected. Not until May 1943 would DuPont managers decide to use the
Operation
The X-10 Graphite Reactor was the world's second artificial nuclear reactor after Chicago Pile-1, and was the first reactor designed and built for continuous operation.[47] It consisted of a huge block, 24 feet (7.3 m) long on each side, of nuclear graphite cubes, weighing around 1,500 short tons (1,400 t), that acted as a moderator. They were surrounded by seven feet (2.1 m) of high-density concrete as a radiation shield.[34] In all, the reactor was 38 feet (12 m) wide, 47 feet (14 m) deep and 32 feet (9.8 m) high.[1] There were 36 horizontal rows of 35 holes. Behind each was a metal channel into which uranium fuel slugs could be inserted.[48] An elevator provided access to those higher up. Only 800 (~64%) of the channels were ever used.[1]
The reactor used
The cooling system consisted of three electric fans running at 55,000 cubic feet per minute (1,600 m3/min). Because it was cooled using outside air, the reactor could be run at a higher power level on cold days.[1][49] After going through the reactor, the air was filtered to remove radioactive particles larger than 0.00004 inches (0.0010 mm) in diameter. This took care of over 99 percent of the radioactive particles. It was then vented through a 200-foot (61 m) chimney.[1] The reactor was operated from a control room in the southeast corner on the second floor.[1]
In September 1942, Compton asked a physicist, Martin D. Whitaker, to form a skeleton operating staff for X-10.[50] Whitaker became the inaugural director of the Clinton Laboratories,[37] as the semiworks became officially known in April 1943.[51] The first permanent operating staff arrived from the Metallurgical Laboratory in Chicago in April 1943, by which time DuPont began transferring its technicians to the site. They were augmented by one hundred technicians in uniform from the Army's Special Engineer Detachment. By March 1944, there were some 1,500 people working at X-10.[52]
Supervised by Compton, Whitaker, and Fermi, the reactor went critical on November 4, 1943, with about 30 short tons (27 t) of uranium. A week later the load was increased to 36 short tons (33 t), raising its power generation to 500 kW, and by the end of the month the first 500 mg of plutonium was created.[53] The reactor normally operated around the clock, with 10-hour weekly shutdowns for refueling. During startup, the safety rods and one shim rod were completely removed. The other shim rod was inserted at a predetermined position. When the desired power level was reached, the reactor was controlled by adjusting the partly inserted shim rod.[1]
The first batch of canned slugs to be irradiated was received on December 20, 1943, allowing the first plutonium to be produced in early 1944.[54] The slugs used pure metallic natural uranium, in air-tight aluminum cans 4.1 inches (100 mm) long and 1 inch (25 mm) in diameter. Each channel was loaded with between 24 and 54 fuel slugs. The reactor went critical with 30 short tons (27 t) of slugs, but in its later life was operated with as much as 54 short tons (49 t). To load a channel, the radiation-absorbing shield plug was removed, and the slugs inserted manually in the front (east) end with long rods. To unload them, they were pushed all the way through to the far (west) end, where they fell onto a neoprene slab and fell down a chute into a 20-foot-deep (6.1 m) pool of water that acted as a radiation shield.[1] Following weeks of underwater storage to allow for decay in radioactivity, the slugs were delivered to the chemical separation building.[55]
By February 1944, the reactor was irradiating a ton of uranium every three days. Over the next five months, the efficiency of the separation process was improved, with the percentage of plutonium recovered increasing from 40 to 90 percent. Modifications over time raised the reactor's power to 4,000 kW in July 1944.
The X-10 semiworks operated as a plutonium production plant until January 1945, when it was turned over to research activities. By this time, 299 batches of irradiated slugs had been processed.[50] A radioisotope building, a steam plant, and other structures were added in April 1946 to support the laboratory's peacetime educational and research missions. All work was completed by December 1946, adding another $1,009,000 (equivalent to $12 million in 2023[57]) to the cost of construction at X-10, and bringing the total cost to $13,041,000 (equivalent to $155 million in 2023[57]).[36] Operational costs added another $22,250,000 (equivalent to $265 million in 2023[57]).[48]
X-10 supplied the
The X-10 chemical separation plant also verified the bismuth-phosphate process that was used in the full-scale separation facilities at Hanford. Finally, the reactor and chemical separation plant provided invaluable experience for engineers, technicians, reactor operators, and safety officials who then moved on to the
Peacetime use
After the war ended, the graphite reactor became the first facility in the world to produce radioactive isotopes for peacetime use.
In August 1948, the reactor was used to produce the first electricity derived from nuclear power. Uranium slugs within an aluminum tube were irradiated within the reactor core. Water was circulated through the tube by means of an automatic feedwater system to generate steam. This steam was fed to a model steam engine, a Jensen Steam Engines #50, which drove a small generator that powered a single bulb. The engine and generator are on display at the reactor loading face, just below the staircase leading to the loading platform.[62]
The X-10 Graphite Reactor was shut down on November 4, 1963, after twenty years of use.
Similar reactors
The
When Britain began planning to build nuclear reactors to produce plutonium for weapons in 1946, it was decided to build a pair of air-cooled graphite reactors similar to the X-10 Graphite Reactor at
As of 2016[update], another reactor of similar design to the X-10 Graphite Reactor is still in operation, the Belgian BR-1 reactor of the
Notes
- ^ a b c d e f g h i j k Rettig, Polly M. (December 8, 1975). National Register of Historic Places Inventory-Nomination: X-10 Reactor, Graphite Reactor (pdf). National Park Service. and Accompanying three photos, interior, undated (32 KB)
- ^ Rhodes 1986, pp. 251–254.
- ^ Rhodes 1986, pp. 256–263.
- ^ Jones 1985, pp. 8–10.
- ^ The Atomic Heritage Foundation. "Einstein's Letter to Franklin D. Roosevelt". Archived from the original on October 27, 2012. Retrieved May 26, 2007.
- ^ The Atomic Heritage Foundation. "Pa, this requires action!". Archived from the original on October 29, 2012. Retrieved May 26, 2007.
- ^ Jones 1985, pp. 14–15.
- ^ Hewlett & Anderson 1962, pp. 36–38.
- ^ a b Hewlett & Anderson 1962, pp. 46–49.
- ^ a b Anderson 1975, p. 82.
- ^ Salvetti 2001, pp. 192–193.
- ^ Hewlett & Anderson 1962, pp. 50–51.
- ^ Jones 1985, p. 91.
- ^ Hewlett & Anderson 1962, pp. 54–55.
- ^ Hewlett & Anderson 1962, pp. 180–181.
- ^ Rhodes 1986, pp. 399–400.
- ^ a b c d Jones 1985, pp. 46–47.
- ^ a b c Oak Ridge National Laboratory 1963, pp. 3–4.
- ^ Jones 1985, pp. 67–72.
- ^ Jones 1985, p. 69.
- ^ Fine & Remington 1972, pp. 134–135.
- ^ Jones 1985, pp. 108–112.
- ^ Holl, Hewlett & Harris 1997, pp. 20–21.
- ^ a b Hewlett & Anderson 1962, pp. 190–193.
- ^ Compton 1956, p. 172.
- ^ Holl, Hewlett & Harris 1997, p. 8.
- ^ Compton 1956, p. 173.
- ^ Oak Ridge National Laboratory 1963, pp. 3–4, 18.
- ^ Jones 1985, pp. 107, 192–193.
- ^ Weinberg 1994, pp. 22–24.
- ^ Jones 1985, pp. 191–193.
- ^ Jones 1985, pp. 204–205.
- ^ Hewlett & Anderson 1962, p. 207.
- ^ a b c d Jones 1985, pp. 204–206.
- ^ Manhattan District 1947, pp. 2.4–2.6.
- ^ a b c Manhattan District 1947, p. S3.
- ^ a b Hewlett & Anderson 1962, pp. 207–208.
- ^ Manhattan District 1947, pp. 2.7–2.8.
- ^ a b Hewlett & Anderson 1962, pp. 209–210.
- ^ Smyth 1945, pp. 146–147.
- ^ Jones 1985, p. 194.
- ^ Hewlett & Anderson 1962, p. 185.
- ^ Hewlett & Anderson 1962, p. 89.
- ^ Gerber 1996, p. 4-1.
- ^ Gerber 1996, p. 4-7.
- ^ Manhattan District 1947, p. S2.
- ^ a b "ORNL Metals and Ceramics Division History, 1946–1996" (PDF). Oak Ridge National Laboratory. ORNL/M-6589. Archived from the original (PDF) on January 28, 2015. Retrieved January 25, 2015.
- ^ a b Manhattan District 1947, p. S4.
- ^ Manhattan District 1947, p. S5.
- ^ a b c Jones 1985, p. 209.
- ^ Jones 1985, p. 204.
- ^ Jones 1985, p. 208.
- ^ Hewlett & Anderson 1962, p. 211.
- ^ Manhattan District 1947, p. S7.
- ^ a b "X-10 Graphite Reactor". Office of Management. United States Department of Energy. Retrieved December 13, 2015.
- ^ Hewlett & Anderson 1962, pp. 306–307.
- ^ Gross Domestic Product deflatorfigures follow the MeasuringWorth series.
- ^ Hoddeson et al. 1993, p. 228.
- ^ Hoddeson et al. 1993, pp. 240–244.
- ^ Creager 2013, p. 68.
- ^ a b "Peacetime use of radioisotopes at Oak Ridge cited as Chemical Landmark". American Chemical Society. February 25, 2008. Retrieved December 12, 2015.
- ^ Garceau, Gil. "World's First Nuclear Power Generated Electricity from Jensen #50 on the X 10 Graphite Reactor 1948". YouTube. Retrieved April 4, 2022.
- ^ Oak Ridge National Laboratory 1963, p. 1.
- ^ a b "X-10 Reactor, Oak Ridge National Laboratory". National Historic Landmarks Program. National Park Service. Archived from the original on May 9, 2015. Retrieved October 7, 2008.
- ^ "Public Tours". Oak Ridge National Laboratory. Archived from the original on December 22, 2015. Retrieved December 12, 2015.
- ISSN 0161-7370.
- ISSN 0362-4331. Retrieved February 13, 2016.
- ^ "Brookhaven Graphite Research Reactor History". Brookhaven National Laboratory. Archived from the original on March 14, 2013. Retrieved February 13, 2016.
- ^ "Brookhaven Lab Completes Decommissioning of Graphite Research Reactor: Reactor core and associated structures successfully removed; waste shipped offsite for disposal". Office of Environmental Management. United States Department of Energy. September 1, 2012. Retrieved February 13, 2016.
- ^ Gowing & Arnold 1974, pp. 277–278.
- ^ Arnold 1992, pp. 9–11.
- ^ Gowing & Arnold 1974, pp. 285–286.
- ^ Gowing & Arnold 1974, p. 404.
- ^ Arnold 1992, p. 15.
- ^ Arnold 1992, pp. 122–123.
- ^ Hill 2013, pp. 18–20.
- ^ "Belgian Reactor 1 – BR1". SCK•CEN Science Platform. Belgian Nuclear Research Centre. Retrieved February 12, 2016.
- ^ Buch & Vandenlinden 1995, p. 120.
- .
- ISSN 1540-6563.
- ^ "BR1 – Belgian Reactor 1". SCK•CEN. Belgian Nuclear Research Centre. Archived from the original on July 4, 2013. Retrieved October 8, 2008.
- ^ "2006 → 50th anniversary BR1" (PDF) (in French). Belgian Nuclear Research Centre. 2006. Archived from the original (PDF) on August 16, 2006. Retrieved December 17, 2015.
References
- ISBN 978-0-333-65036-3.
- OCLC 1982052.
- Buch, Pierre; Vandenlinden, Jacques (1995). L'uranium, la Belgique et les puissances: marché de dupes, ou, chef d'œuvre diplomatique? (in French). De Boeck Supérieur. p. 120. ISBN 978-2-8041-1993-5.
- OCLC 173307.
- Creager, Angela N. H. (2013). Life Atomic: A History of Radioisotopes in Science and Medicine. University of Chicago Press. ISBN 978-0-226-01794-5.
- Fine, Lenore; Remington, Jesse A. (1972). The Corps of Engineers: Construction in the United States (PDF). Washington, D.C.: United States Army Center of Military History. OCLC 834187. Archived from the original(PDF) on February 1, 2017. Retrieved August 25, 2013.
- Gerber, Michele (June 1996). Plutonium Production Story at the Hanford Site: Processes and Facilities History (PDF). Washington, D.C.: OCLC 68435718. HC-MR-0521. Retrieved April 17, 2017.
- Gowing, Margaret; Arnold, Lorna (1974). Independence and Deterrence: Britain and Atomic Energy 1945–52, Volume II: Policy Execution. London: Macmillan.
- OCLC 637004643. Retrieved March 26, 2013.
- Hill, C. N. (2013). An Atomic Empire : a Technical History of the Rise and Fall of the British Atomic Energy Programme. London: Imperial College Press. OCLC 857066061.
- OCLC 26764320.
- Holl, Jack M.; ISBN 978-0-252-02341-5.
- Jones, Vincent (1985). Manhattan: The Army and the Atomic Bomb (PDF). Washington, D.C.: United States Army Center of Military History. OCLC 10913875. Archived from the original(PDF) on October 7, 2014. Retrieved August 25, 2013.
- Manhattan District (1947). Manhattan District History, Book IV, Volume 2 – Pile Project X-10 – Clinton Laboratories (PDF). Washington, D.C.: Manhattan District.
- Oak Ridge National Laboratory (1963). ONRL Graphite Reactor (PDF). Archived from the original (PDF) on February 11, 2017. Retrieved December 13, 2015.
- ISBN 978-0-671-44133-3.
- Salvetti, Carlo (2001). "The Birth of Nuclear Energy: Fermi's Pile". In Bernardini, C.; Bonolis, Luisa (eds.). Enrico Fermi: His Work and Legacy. Bologna: Società Italiana di Fisica: Springer. pp. 177–203. OCLC 56686431.
- ISBN 978-0-8047-1722-9.
- ISBN 978-1-56396-358-2.
Further reading
- Snell, Arthur H.; Weinberg, Alvin M. (1964). "History and accomplishments of the Oak Ridge Graphite Reactor". Physics Today. 17 (8): 32. ISSN 0031-9228.
External links
- "ORNL webpage about the Graphite Reactor". Oak Ridge National Laboratory. Archived from the original on January 12, 2010.
- "Public Tours". Oak Ridge National Laboratory. Retrieved December 12, 2015.
- "National Register Information System – X-10 Reactor, Oak Ridge National Laboratory". National Register of Historic Places. National Park Service. April 15, 2008.
This article incorporates public domain material from X-10 Graphite Reactor. United States Department of Energy. Retrieved December 13, 2015.