B Reactor: Preserving a Transformative Piece of U.S. History

The atomic age began in the New Mexico desert on July 16, 1945, with the Trinity Test — the culmination of the top-secret Manhattan Project.

This first-ever detonation of a nuclear device led to a new era marked by the development of weapons with previously unimaginable power, and a complicated legacy that includes the fields of nuclear medicine and nuclear energy, the growth of a vital national laboratory system and EM’s vast environmental cleanup.

The B Reactor at the Hanford Site was the world’s first full-scale plutonium production reactor, and produced plutonium for the Trinity Test and one of two weapons deployed in August 1945 during World War II. B Reactor is now part of the Manhattan Project National Historical Park. Other historic facilities at Oak Ridge and Los Alamos are also part of the park.

While it only took 11 months in 1943 to construct B Reactor, preserving the reactor and later creating the park took considerably longer. Nonetheless, the decades-long effort exemplifies what is possible through strong partnerships among Congress, local communities, DOE headquarters, EM sites and other federal agencies.

Former B Reactor workers sought recognition for the facility’s historical status, resulting in its designation as a National Historic Mechanical Engineering Landmark in 1976, and a National Historic Civil Engineering Landmark in 1994.

With broad community support, the reactor was added to the National Register of Historic Places in 1992. In 2008, with DOE support, the U.S. Department of Interior designated B Reactor a National Historic Landmark. After a decade of a congressionally mandated study by the National Park Service and DOE, bipartisan legislation was passed by Congress and signed into law in 2014 establishing the park.

Community advocates and local leaders in the three Manhattan Project communities and elsewhere across the nation drove efforts to preserve the reactor.

For EM and Hanford, the vision and tenacity of community leaders and organizations — including the B Reactor Museum Association, the Tri Cities Development Council, local governments and Visit Tri Cities — and the work of their representatives in Congress made the park possible.

EM and Hanford leadership safely preserved the B Reactor and supported the creation of the park, recognizing that providing controlled, safe public access to the historic facilities over time would be a powerful educational tool in explaining the EM mission and progress to taxpayers.

More than 12,000 people typically visit the B Reactor each year, and international visitors have come from more than 90 countries worldwide, bringing an estimated $3 million in tourism to the local community.