B-Reactor

The charging area, or work area, was a large concrete room in front of the charging (front) face of the pile. It was large enough so that any of the 40 ft long aluminum process tubes could be inserted or removed from the pile for maintenance purposes.

The B Reactor was a production pile, and needed an efficient means for adding new fuel to the pile and removing the irradiated, plutonium-bearing fuel, while also maintaining safety for the workers. The combination of the pile’s process tubes and aluminum-clad fuel slugs made this a relatively straightforward process: operators would push new fuel and dummy slugs into a tube from the front face, while any slugs already in the tube would be pushed out the rear face. This process, known as pushing, was therefore one of charging and discharging at the same time. In spite of this simplicity, the process was greatly impeded by several factors:

The 2,004 process tubes averaged 59 fuel and dummy slugs per tube, which added up to a tremendous amount of work, even though only small sections of the pile would be pushed at any one time.
Pushing was an extremely dangerous process; a single discharged fuel slug at the feet of a worker could give a lethal dose of radiation in a matter of seconds.
When the pile was shut down for more than about 20 hours, it could be difficult to get it restarted.