The chemical shim is a boron compound that is added to the coolant to control the rate of nuclear reactions by absorbing neutrons.

Maintaining a high pH in the primary coolant helps to prevent corrosion of the reactor components by forming a protective oxide layer on the metal surfaces.

Zirconium alloy is commonly used for cladding nuclear fuel pellets due to its low neutron absorption cross-section, high corrosion resistance, and good mechanical properties.

Tritium is produced as a byproduct of nuclear fission reactions in the reactor core.

The pressurizer is a component of the primary coolant system that maintains a constant pressure in the system to prevent boiling and cavitation.

The control rods are inserted into or withdrawn from the reactor core to control the rate of nuclear reactions by absorbing neutrons.

Boron carbide is commonly used as a neutron absorber in control rods due to its high neutron absorption cross-section and good mechanical properties.

The moderator is a material used in a nuclear reactor to slow down neutrons to increase the probability of their interaction with fissile atoms.

Heavy water (deuterium oxide) is commonly used as a moderator in nuclear reactors due to its low neutron absorption cross-section and good moderating properties.

The fuel cladding is a barrier that prevents the release of radioactive materials from the fuel pellets into the coolant.

Zirconium alloy is commonly used for fuel cladding due to its low neutron absorption cross-section, high corrosion resistance, and good mechanical properties.

The containment structure is a barrier that prevents the release of radioactive materials into the environment in the event of an accident.

Concrete is commonly used for the construction of containment structures due to its ability to absorb and shield radiation, as well as its structural strength and durability.

The ECCS is a safety system designed to provide cooling to the reactor core in the event of a loss of coolant accident to prevent core damage.

Zirconium alloy is commonly used for the construction of fuel assemblies due to its low neutron absorption cross-section, high corrosion resistance, and good mechanical properties.