Nuclear Power Plant

 

What is nuclear power plant (NPP)? Actually, it can be defined as an electrical generating facility using a nuclear reactor as its heat source to provide steam to a turbine generator. In our country Malaysia, there are many type of electricity-generating power station in Malaysia. The make use of hydro-power, gas-fired, coal-fired (combined gas/coal), oil fired, biomass and hybrid power are remain as the main sources to generate electricity. Our country has enough skilled labor to operate power plant. It is simple because we have experience about how to operate hydro-power, gas-fired, coal-fired and etc.The whole system of power plant including steam turbine generator also we are capable of. How about if we replace the others heat sources with nuclear reactor? The concept stills the same, the steam turbine generator still being used. The different is only the heat source. It is sound easy, but the acceptation of Malaysian about nuclear reactor need to be considered. They need to be provided with simple and true information about nuclear power plant. Nuclear reactor is a device in which nuclear fission may be sustained and controlled in self-supporting nuclear reactor. It is heart of a nuclear power plant. A fissionable material of fuel, a moderating material, a reflector to conserve escaping neutrons, provisions of removal heat, measuring and controlling instruments and protective devices are include as parts of nuclear reactor. Figure above shows the general idea how to use nuclear reactor to produce the electricity.

What are the major components of nuclear reactors? There are 5 major components of nuclear reactor as listed as below.

ª      Nuclear fuel

ª      Moderator

ª      Coolant

ª      Reactivity Control Material

ª      Structural Material

 The nuclear fuel is used to undergo nuclear fission by neutrons. It must have high thermal conductivity, irradiation, chemical stability and also excellent nuclear characteristics. The example fuel that can be used is uranium, etc. The moderator is used to reduce neutron energy by scattering without significant capture. It must have desirable characteristics to function efficiently such as large scattering cross section, small absorption cross section, large energy per collision and low atomic number. The example of moderator can be used are Deuterium, graphite and etc. For coolant, it is use to remove the fission heat from the primary heat source such as a reactor core or breeding blanket. The coolant must have excellent heat transfer, chemical stability, small pumping requirement, irradiation stability and abundance (low cost).The most natural coolant is water. The reactivity control material is needed to control the neutron flux in the core by absorbing neutrons. It can be done by using control rod. The structural material is used to maintain geometry. The structural must has high strength, ductility, corrosion resistance, small absorption cross section and high thermal and irradiation resistance. Zircaloy can be used as material.

 Picture above shows the basic components of nuclear power plant. The most common of nuclear reactor  type  that been used nowadays are Pressurize Water Reactor (PWR) and Boiling Water Reactor (BWR). The picture above shows the example of PWR nuclear reactor type.PWR and BWR and the other type of nuclear reactor that commonly used will be discussed in other post.

   
Reference
*Introduction to Nuclear Engineering  MEHB513