light water moderated Soviet designed reactor

Ordinary light water

Most often, light water (H2O) is used as a moderator in a nuclear reactor. Sometimes, heavy water (D2O), or graphite is used.

This is used in the nuclear reactor that is known as Boiling Water Reactor (BWR) in which heat produced by the nuclear fission in the nuclear fuel allows the light water reactor coolant to boil. Then, the nuclear reactor moisture separator is used to increase the dryness of the produced steam before it goes to the reactor steam turbines.

This is the function of the moderator, which may be heavy water, light water, or graphite