Final answer:
The basic reaction in a nuclear power plant is fission, and overheating of fuel rods can cause a meltdown. Control rods are used to regulate the neutron flux and prevent uncontrolled reactions. Power plants are designed to avoid a supercritical mass and nuclear explosion.
Step-by-step explanation:
The basic reaction that takes place in a nuclear power plant is fission; if the fuel rods get too hot, they can cause a meltdown. In a nuclear reactor, the core consists of nuclear fuel in the form of fuel rods containing a fissionable isotope. Controlled chain reactions are sustained within the reactor to generate heat, which is used to produce electricity. To control the reaction, materials such as palladium or boron, which are efficient neutron absorbers, are used in the design of the control rods. These can be adjusted to regulate the neutron flux and maintain a safe rate of fission.
Failures in systems and safeguards can lead to catastrophic accidents in nuclear power plants, such as chemical explosions and nuclear meltdowns, which result from overheating and damage to the reactor core. It is important to note that nuclear power plants are designed to prevent the formation of a supercritical mass that could lead to a nuclear explosion, ensuring that the chain reaction remains controlled.