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Hanford Site


The Hanford Site is a facility of the government of the United States established to provide plutonium necessary for the development of nuclear weapons. It was established in 1943 as the Hanford Engineer Works, part of the Manhattan Project, and codenamed "Site W." No longer used to produce plutonium, it is currently the United States' most contaminated nuclear site.[1]

The site occupies 586 square miles (1,517 km²) in Benton County, south-central Washington, and is approximately equivalent to half the total area of the state of Rhode Island (centered on 46°30′00″N, 119°30′00″W.) The Federal government bought the towns of White Bluffs and Hanford and all of the surrounding farmland and orchards, and evacuated the residents to make room for the site.

Plutonium manufactured at the Hanford site was used to build the first nuclear bomb, which was tested at the Trinity site near Alamogordo, New Mexico, and used to build Fat Man, the bomb that was dropped on Nagasaki, Japan.

Currently, the Hanford Site is engaged in the world's largest environmental cleanup, with many challenges to be resolved in the face of overlapping technical, political, regulatory, and cultural interests. The cleanup effort is focused on three outcomes: restoring the Columbia River corridor for other uses, converting the central plateau to long-term waste treatment and storage, and preparing for the future.

Although most of the original Hanford Site is in Benton County, approximately twenty percent was once across the Columbia River in Grant and Franklin counties. This land has since been returned to private use and is now covered with orchards and irrigated fields. In 2000, large portions of Hanford were turned over to the Hanford Reach National Monument.


History of the Hanford Nuclear Site

Hanford High School, before and after operation of the Hanford Nuclear Site

The Uranium Committee of the federal Office of Scientific Research and Development (OSRD) decided to sponsor an intensive research project on plutonium. At this time, plutonium was a rare element that had been isolated in a University of California laboratory only nine months prior. The OSRD placed the contract with the University of Chicago Metallurgical Laboratory (Met Lab). Communities surrounding the Hanford Nuclear Reservation in southeastern Washington were exposed to radionuclides, particularly iodine-131, released during the period 1945 to 1951.

Selecting the Hanford Site

In June 1942, the Army Corps of Engineers formed the Manhattan Engineer District (MED) to construct industrial-size plants to manufacture the plutonium and uranium for the Met Lab scientists. In November 1942, the DuPont Company was recruited, and reluctantly agreed, to be the prime contractor for the construction of the facility. DuPont recommended that the plutonium production facilities be located far away from the existing uranium production facilities at Oak Ridge, Tennessee, and described the ideal site:

  • A large and remote tract of land,
  • A "hazardous manufacturing area" of at least 12 by 16 miles (19 by 26 km),
  • Space for laboratory facilities at least 8 miles (13 km) from the nearest reactor or separations plant,
  • No towns of more than 1,000 people closer than 20 miles (32 km) from the hazardous rectangle,
  • No main highway, railway, or employee village closer than 10 miles (16 km) from the hazardous rectangle,
  • A clean and abundant water supply,
  • A large electric power supply,
  • Ground that could bear heavy loads.

Although General Leslie Groves considered five other locations, the Hanford Site was chosen in December 1942 as "ideal in virtually all respects" (Matthias 1987), except for the farming towns of White Bluffs and Hanford. General Groves then established the Hanford Engineer Works. Beginning in February 1943, the Federal Government acquired 670 square miles (1,740 km²) from ~1,300 people (Gephart 2003). Because of wartime food shortages, the Manhattan Project used American prisoners to harvest the fields and orchards.

Construction begins

The Hanford Engineer Works (HEW) broke ground in March 1943, and immediately launched a massive construction project. Before the end of the war in August 1945, the HEW built 554 buildings (in addition to building living quarters and the City of Richland, Washington), including:

  • Three reactors: 105-B ( 46°37′50″N, 119°39′00″W), 105D( 46°42′00″N, 119°32′00″W), and 105-F ( 46°39′47″N, 119°26′50″W),
  • Three 250 meter long plutonium processing canyons: 221-T ( 46°33′45″N, 119°37′05″W), 221-B ( 46°33′25″N, 119°32′25″W), and 221-U ( 46°32′49″N, 119°37′05″W),
  • Away-from-reactor below-grade decay storage basins: 200-N ( 46°35′30″N, 119°34′37″W—coordinates show above-grade structure of the central of 3 railheads with access to the basins)
  • Gable Mountain vault for Plutonium storage ( 46°35′27″N, 119°27′54″W—coordinates show access area to the former in-mountain vault)
  • 64 underground high-level waste storage tanks,
  • Uranium fuel fabrication facilities, laboratories and test reactors in the 300 area ( 46°22′20″N, 119°16′40″W),
  • 386 miles (621 km) of roads,
  • 158 miles (254 km) of railway,
  • 50 miles (80 km) of electrical transmission lines,
  • Four electrical substations,
  • Hundreds of miles of fencing.

The Hanford Engineer Works used 780,000 cubic yards (600,000 m³) of concrete and 40,000 tons of structural steel and consumed US$230 million dollars between 1943 and 1946.  

Building the reactors

The DuPont Company started to build the first Hanford nuclear reactor, B pile (building 105-B), in August 1943. (Fission reactors were originally called "piles".) Construction was completed more than a year later, on September 13, 1944. Testing started on July 12, 1944, and B pile was charged with uranium slugs on September 26, 1944 (Gephart 2003). The uranium slugs were short cylinders, 8 inches (20.3 cm) tall with a 1.4 inch (3.55 cm) diameter (Gephart 2003). Plutonium production began on September 26, 1944 (Gephart 2003). B reactor went critical in late September 1944, and after overcoming nuclear poisoning, produced its first plutonium on November 6, 1944. This plutonium was then refined in the 221-T plant and shipped to Los Alamos, beginning on December 26, 1944 (Gephart 2003). The first shipment was on February 5, 1945, leading the way to future shipments which were used in the Trinity Test and Fat Man, the bomb dropped on Nagasaki, Japan.

After starting construction on B pile, DuPont started construction on two identical reactors, 105-D, which started production in December 1944, and 105-F, which started production in February 1945. All three reactors (105-B, 105-D, and 105-F) initially operated at 250 megawatts (MW).

As no one had ever built an industrial-scale reactor before, the scientists and the DuPont engineering team were unsure how much heat would be generated by fission during normal operations. Seeking the greatest margin of error, DuPont engineers installed ammonia-based refrigeration systems with the 100-D and 100-F reactors to further chill the river water prior to its use as the reactor coolant.[2]

Reactor name Start-up date Shutdown date Initial power (MWt) Final power (MWt) notes
B-reactor September 1944 February 1968 250 2210
D-reactor December 1944 June 1967 250 2165
F-reactor February 1945 June 1965 250 2040
H-reactor October 1949 April 1965 400 2140
DR-reactor October 1950 December 1964 250 2015
C-reactor November 1952 April 1969 650 2500
KW-reactor January 1955 February 1970 1800 4400
KE-reactor April 1955 January 1971 1800 4400
N-Reactor December 1963 January 1987 4000 4000 dual-purpose

Plutonium separation plants

Plutonium was produced in the Hanford reactors when a U-238 atom in a fuel slug absorbed a neutron to form U-239. The U-239 rapidly undergoes beta decay to give Np-239, which rapidly undergoes a second beta decay, giving Pu-239. The irradiated fuel slugs were transported by rail to three huge remotely operated chemical separation plants called "canyons", that were located about 10 miles (16 km) away. A series of chemical processing steps separated the small amount of plutonium that was produced from the remaining uranium and the fission waste products.

After the plutonium was extracted and refined in these plants, it was delivered to Los Alamos for use in the Trinity test device and the "Fat Man" bomb dropped on Nagasaki, Japan.

One issue the duPont team needed to tackle with these plants was that once they began processing irradiated slugs, the machinery would become radioactive to the point that it would be unsafe for humans ever to come in contact with it. They therefore had to devise methods to allow for replacement of any component via remote control. They came up with a modular cell concept, which allowed major components to be removed and replaced entirely by an operator sitting in a heavily shielded overhead crane. The method required early practical application of two technologies quite familiar to us today: Teflon, used as a gasket material, and closed-circuit television to give the crane operator a better view of what he was doing.[4]

On March 10, 1945, a Japanese fire balloon descended in the vicinity of the site. This balloon caused a short circuit in the power lines supplying electricity for the nuclear reactor cooling pumps, but backup safety devices restored power almost immediately.[5]

Cold War era

During the Cold War, the HeW built H-Reactor, with 400 MW, that started in 1949, and DR (for D-Replacement) Reactor, with 250 MW, started up in 1950. C-Reactor (105-C), at 600 MW, was located next to B-Reactor and started in 1952, and soon became the chief development and testing machine at the Hanford site. Within three months of its startup, C-Reactor's primary function was experimentation for the design of the "twin" K-Piles (KE and KW) - the 1955 "jumbos", each outputing 1,800 MW.

By the early 1960s, extensive modifications and upgrades had allowed the five reactors that were built in the 1940s to achieve power levels ranging from 2,015 to 2,210 MW each, C-Reactor achieved a power level of 2,500 MW, and the K-Piles achieved power levels of 4,400 MW each.

The Hanford B-Reactor continued to operate during the Cold War and produced tritium for the hydrogen bomb. B-Reactor was deactivated on February 12, 1968. Since then, most of the surrounding structures have been removed and buried and the other Hanford reactors have been entombed ("cocooned") to allow radioactivity to decay. The B-reactor has not been mothballed and is planned to become a museum.

All nine nuclear reactors were built along Hanford Reach on the Columbia River. With an average individual life span of 22 years, the reactors were closed down between 1964 and 1987.

The Hanford reactors required a huge volume of water from the Columbia River to dissipate the heat that was produced by the nuclear reactions. Huge water systems drew cooling water from the Columbia River and after treating this water for use by the reactors, returned water to the river. Before being pumped back into the river, the used water was held in large tanks known as retention basins for up to six hours. Longer-lived isotopes were not affected by this retention, and several terabecquerels entered the river every day. By the early 1960s, there were protests from the health departments of Oregon and Washington, as well as the U.S. Public Health Service. There were also numerous gas plumes of radioactive steam, which threw toxic iodine isotopes into the air.

Because of the demands for increased plutonium production, the Hanford Reactors had an increasingly severe problem with "slug failures"—the undesirable penetration of a fuel element's aluminum jacket by cooling water that caused the uranium to swell and block the coolant flow within the process tube and melt the slugs within that tube. No slug failures occurred during World War II, but by December 1945, 125 slugs with "blisters" had been found by visual inspection in the irradiated fuel storage basins at the rear of the three reactors. For the next seven years, blistered and ruptured fuel elements were opened and examined using a special underwater lathe in steel tanks located in the 111-B Test Building. After the 327 Post Irradiation Test Facility was ready, with its hot cells, the 111-B Building continued to be used as an examination facility for sections of corroded and failed process tubes.

When fuel ruptures did occur, the process tube containing the failure was emptied into the irradiated fuel storage basin. Sometimes, severe ruptures had to be removed with a rotary reamer and a hydraulic ram, with the damaged process tube then split with a special tube splitter, and then pulled out and chopped into short lengths with a unique Hanford Site instrument known as the "guillotine".

Cleanup era

  During the 25 years that the site operated, many puzzles relating to the practicalities of nuclear piles were solved and new machines developed to improve operating efficiencies. However, while technical operating challenges progressed well, waste disposal solutions remained elusive, and effluents continued to be released to the Columbia River.

Most of Hanford's reactors were shut down in the 1960s but nuclear waste still remains at the site. Parts of the 560 square mile (1,450 km²) site are highly contaminated. Examples of the scale of the problem are:

  • Some 54 million U.S. gallons (204,000 m³) of radioactive liquid and sludge is stored in 177 underground tanks of which about a third were reported as leaking in 2001.
  • Nearby aquifers were not protected and contain an estimated 270 billion gallons of contaminated ground water[6]
  • More than 40 billion gallons (151 million m³) of contaminated water were dumped directly onto the soil and there have been radioactive leaks from storage ponds and tanks
  • The site includes 25 million cubic feet of solid radioactive waste[6]

Cleanup to a nationally accepted level will likely take until 2030 and cost at least $50 billion.[7]. At present, about 11,000 workers work to consolidate, clean up, and mitigate waste, contaminated buildings, and contaminated soil.

Under the present cleanup plan, lower-level hazardous wastes are buried in huge lined pits that are sealed and that will be monitored with sophisticated instruments for many years. The high-level nuclear waste, as well as tanks full of highly toxic chemicals, pose a much more difficult problem. As an example, plutonium has a half-life of 24,100 years, and a decay of ten half-lives is required before a sample is considered to be safe. Disposal of plutonium and other high-level radioactive wastes and toxic chemicals is a difficult problem that continues to be a subject of intense debate. The Department of Energy is currently building a vitrification plant on the Hanford site. Vitrification is a method that will combine these dangerous wastes with glass to render them stable. Bechtel, the San Francisco based construction and engineering firm, has been hired to construct the Vit Plant, which will cost approximately $12 billion and will be operational in 2019. Construction began in 2001.

Clean land released to other uses

  • Arid Lands Ecology Reserve (ALE), 125 square miles (320 km²) on the slopes of Rattlesnake Mountain above and to the west of the Hanford Project. This land was once used as a defensive ground-to-air missile base.
  • National Environmental Research Park, 580 square miles (1500 km²) north and west of WA 240. This area includes the ALE.
  • Hanford Reach National Monument, managed by the U.S. Fish and Wildlife Service. Includes areas open to the public and areas reserved for ecological research. The Wahluke Slope, 90,000 acres (360 km²) on the north bank of the Columbia River (across from the reactor complex), was released in 1999.

Contemporary Hanford


Although uranium enrichment and plutonium breeding have been slowly phased out at Hanford, its strong legacy remains in Richland, Washington, which was transformed from a sleepy farm town to a bustling city by the Hanford project. As the nearest city to the site, the feat of feeding the United States' vast nuclear program in a cold war world created a strong community of highly skilled scientists and engineers.

Hanford became the location of the Department of Energy Pacific Northwest National Laboratory owned by the United States government and operated by Battelle Memorial Institute just north of Richland. A map of the site can be found on the Benton County Emergency Services web site[8]

Other facilities located at Hanford Site:

  • The Fast Flux Test Facility (FFTF), now (2005) in cold standby, is at Hanford.
  • LIGO's Hanford Observatory, an interferometer searching for gravitational waves, operates in tandem with another observatory in Livingston, Louisiana.
  • Columbia Generating Station is a commercial nuclear power plant operated by Energy Northwest.


  • D'Antonio, Michael, Atomic Harvest: Hanford and the Lethal Toll of America's Nuclear Arsenal (New York: Crown, 1993). ISBN 0-517-58981-8
  • Gephart, Roy, Hanford: a Conversation about Nuclear Waste and Cleanup. Columbus: Battelle Press, 2003. ISBN 1-57477-134-5
  • Gerber, Michele et al., National Register of Historic Places Multiple Property Documentation Form - Historic, Archaeological and Traditional Cultural Properties of the Hanford Site, Washington, DOE/RL-97-02, Chapter 5: The Manhattan Project and Cold War Eras, Plutonium Production at the Hanford Site, Washington, December 1942-1990" (February 1997)
  • Weisskopf, Gene, "Historic American Engineering Record B Reactor (105-B Building)," HAER No. WA-164 (December 2000) This Report has been scanned but is not yet online.
  1. ^ Dininny, Shannon. "Feds to assess damage to nature at Hanford", The Olympian, The Associated Press, 4 April 2007. Retrieved on 2007-04-04. 
  2. ^ Sanger, S. L., Working on the Bomb: an Oral History of WWII Hanford, p.70
  3. ^ Plutonium: the first 50 years: United States plutonium production, acquisition, and utilization from 1944 through 1994. U.S. Department of Energy.
  4. ^ Sanger (interview with Genereaux)
  5. ^ History of the Plutonium Production Facilities at the Hanford Site Historic District, 1943-1990 Retrieved 27 April 2007
  6. ^ a b Wolman, David. "Fission Trip", Wired Magazine, April 2007, p. 78. 
  7. ^ "A River Dammed" by Fen Montaigne. National Geographic, April 2001, pp. 24-25.
  8. ^
  • Hanford Site is at coordinates 46°32′11″N 119°31′12″W / 46.536389, -119.520000Coordinates: 46°32′11″N 119°31′12″W / 46.536389, -119.520000
  • Site W: Hanford, WA A map of Manhattan Project Era Hanford, Washington
  • Atomic Heritage Foundation Historic Preservation of Manhattan Project Sites at Hanford
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Hanford_Site". A list of authors is available in Wikipedia.
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