The B Reactor National Historic Landmark
The B Reactor National Historic Landmark is the world's first full-scale plutonium production reactor and part of the Manhattan Project National Historical Park administered by the U.S. Department of Energy and the National Park Service. Tours offer more information about the people, events, science, and engineering that led to the creation of the atomic bombs that helped bring an end to World War II.
2025 Tour Season Details
The 2025 Manhattan Project National Historical Park (MAPR) B Reactor tours are suspended due to major construction projects set to begin this spring. We look forward to hosting you after those projects are complete. Meanwhile, the MAPR Pre-Manhattan Project Historical Sites tours will continue, beginning in April. Please sign up at this link for specific dates and times
Web Links
Learn more about the world-changing history, science and engineering behind the Manhattan Project and B Reactor, as well as the history of Native American and early settler populations at the Hanford Site, with videos produced by the B Reactor Museum Association and the Atomic Heritage Foundation.