Telling a gigantic story: the B Reactor tour in Hanford, Washington

The Manhattan Project created three nuclear bombs, which lend to the end of World War II. The Fat Man plutonium bomb dropped on Nagasaki had a yield of 21 kilotons, or 21,000 tons of TNT. It weighed 5 tons, so it was ~4200 times more powerful than a conventional bomb.  

Plutonium for two bombs was created in a nuclear reactor – the B Reactor at the gigantic Hanford Engineer Works on the south bank of the Columbia River in Washington.

On May 8, 2019 I took a tour of the B Reactor National Historical Landmark. B Reactor at Hanford was the first nuclear reactor able to operate continuously. (Its two brothers the D and F reactors came a bit later). The tour took four hours, and mine started at 9:00 AM. It began at a visitor center in Richland, Washington. We took a bus trip (an hour each way) out to the reactor site.

On the wall of the corridor there are a pair of blue wall posters that succinctly explain the B reactor and Hanford. Starting in March 1943 95,000 people worked on the site. Construction of B reactor began in June 1943. It started operating at the end of September 1944, and by summer of 1945 it had produced plutonium for two bombs.

At the site you can look at the front face of the reactor and the inlet ends of the fuel tubes. The core is a 36’ high by 36’ wide stack of graphite blocks 28’ deep. A couple thousand aluminum tubes go through it and hold the natural uranium fuel.

The tubes also carried 30,000 gallons per minute of cooling water to remove heat from the fission reaction – 250 million watts. As shown above in a closeup, a maze of piping and valves distributes water to all the tubes.  

The room where you look at the front face of the reactor also has a scale model of the adjacent part of the site. On the overall view I put a red circle around the B reactor. Other buildings for processing the water for cooling dwarf the actual reactor building (#105). There were three systems for providing cooling water. The primary normal one used electric pumps. A backup used steam powered pumps. A third emergency gravity fed system used a pair of large water tanks.

The room also has a another model showing how the graphite blocks were stacked to make the core.

There also is a poster explaining the fission reactions which almost magically create plutonium from natural uranium.

In the control room there’s a console with a chair for the operator. To the right of it is a whole wall full of running time meters that keep track of how long the fuel loaded in each tube was in the reactor.

What Hanford was doing was top secret, and you could get into big trouble by talking about it. Near the control room is a room with a safe which curiously has a roll of toilet paper sitting inside. The woman tour leader told us a story about that. One day a schoolboy told his class that he had figured out what they were making at the site. He’d seen his dad smuggle a roll home, so it just was toilet paper!     

             

The tour leader told us that the most popular part was a poster showing dining halls on the Hanford site. Along with it there was a list titled A Lot of Workers, A Lot of Food. Everyone could appreciate what was involved in feeding that mass of workers. She said the 30,000 donuts a day were an incentive plan to get people to show up early or on-time for breakfast and then work. If you weren’t early you wouldn’t get one.