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 or HNR, and the Hanford Project. Established in 1943 as part of the Manhattan Project in the town of Hanford in south-central Washington, the site was home to the B Reactor, the first full-scale plutonium production reactor in the world. Plutonium manufactured at the site was used in the first nuclear bomb, tested at the Trinity site, and in Fat Man, the bomb detonated over Nagasaki, Japan.

During the Cold War, the project was expanded to include nine nuclear reactors and five large plutonium processing complexes, which produced plutonium for most of the 60,000 weapons in the U.S. nuclear arsenal. Nuclear technology developed rapidly during this period, and Hanford scientists produced many notable technological achievements. Many of the early safety procedures and waste disposal practices were inadequate, and government documents have since confirmed that Hanford's operations released significant amounts of radioactive materials into the air and the Columbia River, which threatened the health of residents and ecosystems.

The weapons production reactors were decommissioned at the end of the Cold War, but the decades of manufacturing left behind 53 million US gallons (200,000 m3) of high-level radioactive waste, an additional 25 million cubic feet (710,000 m3) of solid radioactive waste, 200 square miles (520 km2) of contaminated groundwater beneath the site and occasional discoveries of undocumented contaminations that slow the pace and raise the cost of cleanup.

The Hanford site represents two-thirds of the nation's high-level radioactive waste by volume. Today, Hanford is the most contaminated nuclear site in the United States and is the focus of the nation's largest environmental cleanup. While most of the current activity at the site is related to the cleanup project, Hanford also hosts a commercial nuclear power plant, the Columbia Generating Station, and various centers for scientific research and development, such as the Pacific Northwest National Laboratory and the LIGO Hanford Observatory.