The Hanford Site

The Hanford Site, also referred to as Hanford Engineer Works or Site W, is a decommissioned nuclear production complex located along the Columbia River in Benton County, Washington. Established in 1943, it was a secret facility of the Manhattan Project, selected for its abundant river water, hydroelectric power, mild climate, strong transport links, and remote location.

Image: United States Department of Energy - Image N1D0069267., "Nuclear reactors line the riverbank at the Hanford Site along the Columbia River in January 1960. The N Reactor is in the foreground, with the twin KE and KW Reactors in the immediate background. The historic B Reactor, the world's first plutonium production reactor, is visible in the distance."

Construction began in 1943, and by September 1944, the B Reactor became operational, making it the world's first full-scale industrial plutonium reactor. This reactor supplied plutonium for the Trinity Test and for the “Fat Man” bomb dropped over Nagasaki. The site was the next logical step in the development of nuclear weapons after the successful Chicago Pile-1, which ushered in the nuclear age into the world in an incredibly short amount of time; just 13 months under the oversight of DuPont and physicist Enrico Fermi.

"This is a World War II photo of the historic "B Reactor" at Hanford, Wash., which was the world's first plutonium production reactor. The Hanford nuclear reservation sits along the Columbia River." - Via OPB

Over the Cold War, Hanford expanded to include nine nuclear reactors and five plutonium separation complexes, producing much of the plutonium for the U.S. nuclear arsenal, which at its peak was estimated at over 60,000 weapons. That said, nuclear technology was not only for weapons, as it also nurtured other nuclear technologies, such as powering the first fully submerged submarine circumnavigation.

A Milwaukee Road line running from Beverly Junction, WA to Riverland, WA exclusively served the Hanford Site, as did a Burlington Northern line running west of Mesa, WA. (Right of way map)

According to Atomic Heritage, "Trains were an important part of the smooth functioning of the Manhattan Project at Hanford. After irradiated fuel from the B Reactor had cooled off in the storage basin full of water for about 90 days, workers used twenty-foot-long tongs to place the irradiated fuel into buckets.

To transport the fuel to the chemical separation plants, engineers designed special lead-lined cask cars. The fuel elements were loaded, under water, into a cask, which was sealed with a lid. A locomotive pulled the cask cars for their ten-mile journey to the three chemical separations plants, entering them through a railroad tunnel. Two 125-ton locomotives and two cask cars are on display at B Reactor. A bucket with fake slugs illustrates the once “hot” cargo."

Image from a pamphlet on railroad preservation at the site.

As one of the earliest sites where radioactive waste was produced, much of the early safety protocols for the site were ineffective or non-existent; and as such, the site is among the most polluted in the US to this day. Radioactive discharges and improper storage led to leaks and health problems in the surrounding communities. 

In 1989, a project to clean up the site was spearheaded by the State, EPA, and DOE. While cleanup was projected at $57 billion over 30 years, mismanagement has ballooned costs into the hundreds of billions, with cleanup now projected to extend into the next century. Hanford now stores roughly 56 million gallons of radioactive waste in aging underground tanks, and efforts are ongoing to vitrify (turn into glass) this waste via the Waste Treatment and Immobilization Plant (Vit Plant). Low-activity waste vitrification began around 2023; high-level waste processing continues to face technical and budgetary hurdles. Recent staffing cuts and turnover have raised concerns among environmental groups, Indigenous tribes, and local communities about oversight and timely progress.

Before nuclear development, the site was home to Native American tribes, and archaeological remnants, artifacts, and burial grounds remain, which are protected by law. The Hanford History Project at WSU Tri-Cities records personal histories, especially aiming to document perspectives of African American workers, Indigenous communities, and marginalized voices tied to the site’s pre-nuclear past.

The Hanford Horticultural Exchange Building, part of pre-nuclear age Hanford, WA, where a Milwaukee Road boxcar is unloaded. (Image via The Hanford History Project at Washington State University Tri-Cities)

In 2015, it, along with two other important sites in the Manhattan Project, Los Alamos, NM and Oak Ridge, TN, it became part of the Manhattan Project National Historical Park. Visitors can explore scientific legacy and human stories, though as of 2025, tours at B Reactor are currently paused due to construction; alternative programs like “Atomic Explorations” continue.

A 2018 aerial image of the remaining buildings at the 300 Area, most of which have since been demolished as of 2025. (Hanford Site)

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