How do nuclear power plants control the rate of nuclear fission?

Nuclear power plants control the rate of nuclear fission through the use of control rods.

Nuclear power plants generate electricity by using the heat produced by nuclear fission to create steam, which drives turbines. However, if the rate of fission is not controlled, the reaction can quickly become uncontrollable and lead to a nuclear meltdown. To prevent this, control rods made of materials such as boron or cadmium are inserted into the reactor core. These rods absorb neutrons, which slows down the rate of fission.

The control rods are attached to motors that can move them in and out of the reactor core. By raising or lowering the control rods, the amount of neutrons that are absorbed can be adjusted, which in turn controls the rate of fission. If the reactor needs to produce more heat, the control rods can be lifted to allow more neutrons to interact with the fuel. Conversely, if the reactor needs to produce less heat, the control rods can be lowered to absorb more neutrons.

In addition to control rods, nuclear power plants also use other safety features to control the rate of fission. For example, the reactor is surrounded by a thick concrete shield that helps contain any radiation that might be released in the event of an accident. The plant also has backup cooling systems that can be used to cool the reactor in case of an emergency. These safety features, along with the use of control rods, help ensure that nuclear power plants operate safely and efficiently.