How is heat produced in a nuclear reactor during fission?

In a nuclear reactor during fission, heat is produced primarily from the kinetic energy of fission fragments. When a heavy nucleus, such as uranium-235, absorbs a neutron, it becomes unstable and undergoes fission, splitting into two smaller nuclei known as fission fragments. This process releases a significant amount of energy, primarily in the form of kinetic energy, as the fission fragments are propelled apart at high speeds.

As these fragments collide with nearby particles and interact with the surrounding material, their kinetic energy is converted into thermal energy, thus raising the temperature of the reactor coolant. This heat is crucial for the generation of steam, which is used to drive turbines for electricity production.

While radiation release and neutron absorption are important aspects of the fission process, they are not the primary sources of heat generation in a reactor. Chemical reactions do not play a role in the nuclear fission process as it is fundamentally a nuclear reaction, not a chemical one. Therefore, the correct understanding of heat production in a nuclear reactor centers on the kinetic energy resulting from the fission of heavy nuclei.