CBSE NOTES CLASS 12 PHYSICS
CHAPTER 13 NUCLEUS
Structure of nuclear reactor
Usually pellets of uranium oxide (UO2) are arranged in tubes to form fuel rods. The rods are arranged into fuel assemblies in the reactor core.
Material in the core which slows down the neutrons released from fission so that they cause more fission. It is usually water, but may be heavy water or graphite.
These are made with neutron-absorbing material such as cadmium, hafnium or boron, and are inserted or withdrawn from the core to control the rate of reaction, or to halt it
Coolant in nuclear reactor
This is a fluid circulating through the core so as to transfer the heat from it. In light water reactors the water moderator functions also as primary coolant.
Pressure vessel or pressure tubes in nuclear reactor
Usually a robust steel vessel containing the reactor core and moderator/ coolant, but it may be a series of tubes holding the fuel and conveying the coolant through the surrounding moderator.
Steam generator in nuclear generator
This is the part of the cooling system of pressurised water reactors, where the high-pressure primary coolant bringing heat from the reactor is used to make steam for the turbine.