This was the first full scale nuclear reactor in the world, and was brought up slowly to test it out.
Hanford B Reactor tour by Studio McGraw
. Source. 2016.- youtu.be/8rlVHEY7BF0?t=335 good description of the fuel element. It uses uranium metal, not Uranium dioxide
- youtu.be/8rlVHEY7BF0?t=652 N Reactor and F Reactor were identical, and came up 2 months later, but much faster because of what they learned on the B
This was an intermediate step between the nuclear chain reaction prototype Chicago Pile-1 and the full blown plutonium mass production at Hanford site. Located in the Oak Ridge National Laboratory.
Exterior of the X-10 Graphite Reactor in 1950
. Source. 
Workers loading Uranium into the X-10 Graphite Reactor with a rod
. Source. 