Nuclear Reactors Nuclear Chemistry 10. There are different types of nuclear reactors . Most are used for power generation, but some can also produce plutonium for weapons and fuel. Two components are common to all reactors, control rods and a coolant.
Control rods determine the rate of fission by regulating the number of neutrons.
These rods consist of neutron-absorbing elements such as boron. The coolant removes the heat generated by fission reactions. Water is the most common coolant, but pressurized water, helium gas, and liquid sodium have been used. Therefore, these reactors require a moderator to slow neutrons from high speeds upon emerging from fission reactions. Today, most U.S. reactors used for generating electric power employ light water as both moderator and coolant.