Hanford B Reactor
U.S. Department of Energy, Richland, Washington
B Reactor at the Hanford Site in southeastern Washington was the world's first full-scale plutonium production reactor, started in September 1944. It made plutonium for the Trinity test and the Nagasaki bomb, then ran again for Cold War production until 1968. It became a National Historic Landmark in 2008 and has offered public tours since 2009.
- Company
- U.S. Department of Energy
- Status
- Closed
- Opened
- 1944
- Employees
- Not stated
- Industry
- Aerospace and defense
- Revised
- November 12, 2026
What is made here
Produced plutonium for the Manhattan Project, including for the Trinity test and the Nagasaki bomb, and later for Cold War weapons.
Facts
| Construction | Construction began in October 1943; fuel was loaded on September 13, 1944 and the reactor reached full power in February 1945 (federal: hanford.gov) |
|---|---|
| Output | Made plutonium for the Trinity Test and for the atomic bomb dropped on Nagasaki (federal: hanford.gov) |
| Shutdown | Closed at the end of 1946, restarted in 1948 for Cold War plutonium production and permanently shut down on February 12, 1968 (federal: hanford.gov) |
| Landmark | Designated a National Historic Landmark in 2008, after listing on the National Register of Historic Places in 1992 (federal: hanford.gov) |
| Tours | Public tours began in early 2009; by 2012 about 10,000 people visited each year (federal: hanford.gov) |
Figures are as stated by the source named next to each one. Company figures are the company's own claims.
Can you visit?
Yes: Bonneville Lock and Dam Visitor Centers (Washington Shore powerhouse viewing) has hours, booking and age rules checked on the operator's site.
Sources
- U.S. DOE Hanford: B Reactor (federal, checked November 12, 2026)
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