Graphing the rate of power increase in these devices over time shows a discontinuity called the "prompt jump". Assuming one of these devices is non-infinite requires adding two non-leakage probability values to the four-factor formula, creating the six-factor formula. Point kinetics equations are used to describe these devices when they have a nonzero excess multiplication factor. These devices can undergo a positive feedback loop when their void coefficient becomes very positive, and buildup of (*) xenon in these device can lead to a "poison outage". Experimental versions of these devices use molten salt as a coolant, and those that can generate more material than they consume are called "breeders". Either heavy water or graphite rods can be used as moderators to 
Graphing the rate of power increase in these devices over time shows a discontinuity called the "prompt jump". Assuming one of these devices is non-infinite requires adding two non-leakage probability values to the four-factor formula, creating the six-factor formula. Point kinetics equations are used to describe these devices when they have a nonzero excess multiplication factor. These devices can undergo a positive feedback loop when their void coefficient becomes very positive, and buildup of (*) xenon in these device can lead to a "poison outage". Experimental versions of these devices use molten salt as a coolant, and those that can generate more material than they consume are called "breeders". Either heavy water or graphite rods can be used as moderators to control the neutron flux in these devices, and they typically use enriched uranium fuel. For 10 points, name these devices which use fission to produce energy.
Graphing the rate of power increase in these devices over time shows a discontinuity called the "prompt jump".
nuclear reactor [or fission reactor after "fission" is read]