B Reactor | |
 The face of B Reactor during construction. | |
   | |
| Location | About 5.3 miles (8.5 km) northeast of junction ofState Route 24 andState Route 240 on theHanford Site |
|---|---|
| Nearest city | Richland, Washington |
| Coordinates | 46°37′49″N119°38′50″W / 46.63028°N 119.64722°W /46.63028; -119.64722 |
| Area | 9.5 acres (3.8 ha) |
| Built | 7 June 1943[1] to September 1944[2] |
| Architect | E.I. DuPont de Nemours & Company |
| NRHP reference No. | 92000245 |
| Significant dates | |
| Added to NRHP | 3 April 1992 |
| Designated NHL | 19 August 2008[3] |
TheB Reactor at theHanford Site, nearRichland, Washington, was the first large-scalenuclear reactor ever built, at 250MW. It achieved criticality on September 26, 1944. This reactor was of vital importance to theManhattan Project, theUnited States nuclear weapons development program duringWorld War II. Its purpose was to convert part of itsnatural uranium fuel intoplutonium-239 byneutron activation, for use in nuclear weapons. Pure plutonium was thenchemically separated at the site's T Plant, as an alternative to the Project'suranium enrichment plants in Tennessee. The B reactor wasgraphitemoderated andwater-cooled, via acontaminating open cycle with theColumbia River.
It was preceded byClinton Laboratory'sX-10 Graphite Reactor, apilot plant for reactor production and chemical separation of plutonium, which by mid-1944 had reached a capacity of 4 MW. The B reactor thus represented a massive leap of two orders of magnitude in reactor design. Primarily constructed byDuPont, the operation was assisted by scientists includingEnrico Fermi,John Archibald Wheeler, andChien-Shiung Wu. Two identical reactors, the D Reactor and F Reactor, were launched in December 1944 and February 1945. The plutonium from the site was used in theTrinity test, theFat Man bombdetonated above Nagasaki, thedemon core, and thousands of US warheads during theCold War. By the early 1960s, the reactors had been upgraded to capacities of 2000 MW. It is historically significant as the world's first large-scale reactor, the first to use water cooling, the first to experiencexenon poisoning, the first employed forthermonuclear weapontritium production, and the seventh critical assembly in total.
The reactor was permanently shut down in February 1968. It has been designated a U.S.National Historic Landmark since 19 August 2008[3][4] and in July 2011 the National Park Service recommended that the B Reactor be included in theManhattan Project National Historical Park commemorating the Manhattan Project.[5] Visitors can take a tour of the reactor by advance reservation.[6]
The reactor was designed and built byE. I. du Pont de Nemours and Company based on experimental designs tested byEnrico Fermi at theUniversity of Chicago, and tests from theX-10 Graphite Reactor atOak Ridge National Laboratory. It was designed to operate at 250megawatts (thermal).
The purpose of the reactor was to breed plutonium from natural uranium metal. Enriching fissionable235U from238U, the dominant natural isotope, was extremely complex; plutonium's distinct chemistry made separation trivial by comparison. For example, theY12 uranium enrichment plant inTennessee required 14,700 tons ofsilver loaned by theTreasury Department for thewindings in itscalutrons, employed 22,000 people and consumed more electrical power than moststates. Reactor B on the other hand needed only a few dozen employees and far fewer exotic materials required in much smaller quantities. The most important special material needed were the 1,200 tons of purified graphite forneutron moderation, and only enough electricity to run the cooling pumps.[7][8]
The reactor has a footprint of 46 by 38 ft (14 by 12 m) (about 1,750 sq ft (163 m2) and is 41 ft (12 m) tall, giving a volume of 71,500 cu ft (2,020 m3). Thereactor core itself consists of a 36 ft-tall (11 m) graphite box measuring 28 by 36 ft (8.5 by 11.0 m) occupying a volume of 36,288 cu ft (1,027.6 m3) and weighing 1,200 short tons (1,100 t). It is penetrated horizontally through its entire length by 2,004 aluminum tubes containing fuel and vertically by channels housing thecontrol rods.[4]
The core is surrounded by athermal shield ofcast iron 8 to 10 in (20 to 25 cm) thick weighing 1,000 short tons (910 t).Masonite and steel plates enclose the thermal shield on its top and sides, forming a biological shield forradiation protection. The bottom of the thermal shield was supported by a 23 ft-thick (7.0 m) concrete pad topped by cast-iron blocks. Based on the success of thefirst atomic pile,graphite was selected tomoderate thenuclear reaction. This reaction was fueled by 200 short tons (180 t) of metallicuranium slugs approximately 25 mm (1 in) diameter, 70 mm (3 in) long (about as large as of a roll ofquarters[4]), sealed in aluminum cans, and loaded into the aluminum tubes.[4]
The reactor waswater-cooled. Its coolant was pumped from theHanford Reach of theColumbia River, through the aluminum tubes and around the uranium slugs at a rate of 75,000 US gal (280,000 L) per minute. The water was discharged intosettling basins. Water was held in the basins to permit thedecay ofshort-livedradioactive waste, the settling out of particulate matter gathered from the reactor, and for the water to cool to within 11 °F of the river's temperature. It was then discharged back into the Columbia River.[9]
The B Reactor had its firstnuclear chain reaction in September 1944, the D Reactor in December 1944 and the F Reactor in February 1945. The initial operation was halted by a problem identified as neutron absorption by the fission productXe-135, first identified in a research paper ofChien-Shiung Wu that was shared with Fermi.[10] It was overcome by increasing the amount of uranium charged. The reactor producedplutonium-239 by irradiatinguranium-238 withneutrons 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.[4]
Emergency shutdown of the reactor, referred to as aSCRAM, was attained either by rapidly fully inserting the vertical safety rods or, as a backup method, by the injection ofborated water into the reactor. In January 1952, the borated water system was replaced by a "Ball-3X" system that injectednickel-plated high-boron steel balls into the channels occupied by the vertical safety rods.[4]
The plutonium for thenuclear bomb used in theTrinity test inNew Mexico and theFat Man bombdropped on Nagasaki, Japan was created in the B reactor. The B Reactor ran for two decades, and was joined by additional reactors constructed later. It was permanently shut down in February 1968.[4][11]
TheUnited States Department of Energy has administered the site since 1977[12][13] and offers public tours on set dates during the spring, summer, and fall of the year, as well as special tours for visiting officials.[6][14]
As of 2014[update] six of the nine production reactors at Hanford were considered to be in "interim safe storage" status, and two more were to receive similar treatment. The exception was the B Reactor, which was given special status for its historical significance.[15]
In a process called cocooning orentombment, the reactor buildings are demolished up to the 4 ft-thick (1.2 m)concrete shield around thereactor core. Any openings are sealed and a new roof is built.[16] Most auxiliary buildings at the first three reactors have been demolished, as well.The C reactor was put into operation in 1952 and was shut down in 1969.[17] It was cocooned as of 1998.[18]The D reactor operated from 1944 to June 1967, and was cocooned in 2004. The DR Reactor went online in October 1950,[19] and was shut down in 1964. It was cocooned in 2002.[20]The F reactor was shut down in June 1965 and cocooned in 2003.[21]The H Reactor became operational as of October 1949 and was shut down as of April 1965. It was cocooned as of 2005.[22]Cocooning of theN-Reactor, which operated from 1963 to 1987, was completed as of 14 June 2012.[23]The decommissioned reactors are inspected every five years by the Department of Energy.[18]
The K East and K West reactors were built in the 1950s and went into use in 1955. They were shut down in 1970 and 1971, but reused temporarily for storage later.[24]Preliminary plans for interim stabilizing of the K-East and K-West reactors were underway as of 30 January 2018.[16]
The B Reactor was added to theNational Register of Historic Places (#92000245) on 3 April 1992. A Record of Decision (ROD) was issued in 1999, and an EPA Action Memorandum in 2001 authorized hazards mitigation in the reactor with the intention of allowing public tours of the reactor.[25] It was named aNational Historic Landmark on 19 August 2008.[3][4]
In December 2014, passage of the 2015National Defense Authorization Act (NDAA) made the B reactor part of theManhattan Project National Historical Park, which also includes historic sites atOak Ridge, Tennessee andLos Alamos, New Mexico.[26][27] The park was formally established by a Memorandum of Agreement on November 10, 2015, which was signed by theNational Park Service and theDepartment of Energy. Museum development at Hanford may include the B Reactor, Bruggemann's Warehouse, Hanford High School, Pump House, and White Bluffs Bank.[28]
| Year | Date | Event |
|---|---|---|
| 1943 | October | U.S. Army Corps of Engineers breaks ground to build B Reactor[29] |
| 1944 | 13 September | First uranium fuel slug loaded into B Reactor[29] |
| 1944 | 26 September | Initial reactorcriticality achieved[29] |
| 1945 | 3 February | B Reactor plutonium delivered toLos Alamos[29] |
| 1945 | 16 July | B Reactor plutonium used inworld's first nuclear explosion. (Trinity Test Site,New Mexico)[29] |
| 1945 | 9 August | B Reactor plutonium used inFat Manbomb dropped onNagasaki, Japan[29] |
| 1946 | March | B Reactor operations suspended[29] |
| 1948 | June | B Reactor operation resumed[29] |
| 1949 | March | B Reactor begins production oftritium for use inhydrogen bombs[29] |
| 1954 | 1 March | First use of B Reactor tritium ina test detonation of a hydrogen bomb atBikini Atoll[citation needed] |
| 1968 | January 29 | Atomic Energy Commission directs shutdown of B Reactor[29] |
| 1976 | B Reactor declaredNational Historic Mechanical Engineering Landmark byAmerican Society of Mechanical Engineers[29] | |
| 1994 | B Reactor declaredNational Historic Civil Engineering Landmark byAmerican Society of Civil Engineers[29] | |
| 2008 | B Reactor declaredNational Historic Landmark byU.S. Department of Interior andNational Park Service[29] | |
| 2009 | U.S. Department of Energy announces public tours[30] | |
| 2011 | July | National Park Service recommends B Reactor be included in a national historic park commemorating theManhattan Project.[5] |
| 2014 | December | 2015National Defense Authorization Act (NDAA) includes B reactor inManhattan Project National Historical Park[26] |
| 2015 | 10 November | Manhattan Project National Historical Park formally established by Memorandum of Agreement[28] |
Construction began on June 7, 1943...
Completed in September 1944...
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