The primary function of a nuclear reactor coolant system is to remove heat from the reactor core, which is generated by the nuclear fission reaction.

Water is a common type of nuclear reactor coolant due to its high heat capacity, low cost, and availability.

The purpose of a nuclear reactor moderator is to slow down neutrons, which increases the probability of them being absorbed by uranium-235 atoms and causing fission.

Nuclear runaway is the term for the uncontrolled release of energy from a nuclear reactor, which can lead to a nuclear meltdown or explosion.

All of the above are safety systems used in nuclear reactors to prevent or mitigate accidents.

Heat transfer in a nuclear reactor core occurs through conduction, convection, and radiation.

Convection is the process by which heat is transferred from a solid surface to a fluid.

Radiation is the process by which heat is transferred through electromagnetic waves.

Thermal conductivity is the term for the ratio of the heat flux to the temperature difference across a material.

Specific heat capacity is the term for the amount of heat required to raise the temperature of a unit mass of a substance by one degree Celsius.

Pressure is the term for the force per unit area exerted by a fluid.

Viscosity is the term for the resistance of a fluid to flow.

Mass flow rate is the term for the rate of flow of a fluid.

Kinetic energy is the term for the energy possessed by a fluid due to its motion.

Potential energy is the term for the energy possessed by a fluid due to its position or elevation.