Why must the chain reaction of fission be controlled?

The necessity to control the chain reaction of fission is crucial primarily to ensure that sufficient power is produced without leading to an explosion. In a nuclear reactor, fission involves the splitting of atomic nuclei, releasing a significant amount of energy. If this reaction is not controlled, it can lead to an uncontrolled chain reaction, where the rate of fission might increase rapidly, resulting in an immense release of energy and possibly catastrophic outcomes, such as an explosion.

By managing the fission process carefully, operators can maintain a stable output of power that meets energy demands while preventing the dangerous consequences of rapid energy production. Control mechanisms, such as control rods that absorb neutrons, are utilized to modulate the rate of fission reactions to keep the system safe and stable.

The other options are focused more on specific misconceptions. For instance, increasing uranium usage doesn’t directly relate to the control of the chain reaction, nor does preventing the reactor from falling apart or preventing it from becoming a black hole truly capture the concern about safety and power management in nuclear fission processes.