The operators at B Reactor would have more than 5,000 instruments to monitor. Some instruments would display their readings, others record them, sound an alarm, or actually control the pile. Just about all of them were in the control room, located at the left of the pile and below the horizontal control rod rooms. It was here that personnel controlled the power level of the pile and monitored the reactivity of the pile, the temperature of the graphite and shields, the temperature, pressure, and flow rate of the cooling water, and much more.
Operators would monitor and control the pile from the control room, which can be seen in the cutaway view of 105-B. Other processes outside the 105-B building, such as the water pumping and treatment facilities, generally had their own, state-of-the-art conventional measurement and control systems.
One operator sat in front of the main control panel in the control room, where he could watch the instruments that displayed the pile’s power level and control rod positions. An annunciator displayed 28 conditions, any one of which would automatically scram the pile or sound an alarm for operator intervention. The operator could adjust the control rods to maintain the pile’s reactivity at the specified level, and could also push a button to scram the pile when it was deemed necessary.