Nuclear Power Plants what are they? How do they Work?

INTRODUCTION

- Atom consist of electron, neutron and proton

- Neutrons and Protons are concentrated in Nucleus

- X-chemical symbol of atom

- z-atomic number

- A- mass number

BASIC PRINCIPLE OF NUCLEAR POWER PLANTS

- Atoms having same number of protons and having different mass is known as “isotopes”

- Some isotopes of some elements are unstable and disintegrate spontaneously

- Isotopes that are not stable emit radiation till more stable nucleus is reached. This radioactive decay consists of radioactive rays

- In nuclear reactors uranium atom is used 92U235. This atom is hit by a neutron  and split into two or more atoms. This process is known as “fission”.

The fission product is accomplished by one or more neutron and head energy (small amount)

- Fusion is the process of combining atoms get the new atoms and releases large amount of energy.

- Nuclear power plant is special type of  power plant in which the nuclear fission is used to produce electrical energy through a various process.

COMPONENT OF NUCLEAR REACTOR

• Nuclear fuel
• Control rods
• Moderator to slow the neutrons
• Reflector to stop the neutrons to escape
• Coolant to cool the reactor core
• Shielding to protect against radiation from escaping reactor.
• Nuclear fuel may be in the from of solid, liquid or gases

• Fuel that is used  :

Uranium -235; Plutonium-239; Plutonium-241

• Uranium can be naturally found
• The rate of reaction is controlled by the control rod which is able to absorb the neutrons

• When all control rods are inserted to the rector core then reactor
  
  shuts down
• The water level of the reactor core also is important. The core should be fully covered
• Moderator: This material in the reactor core is used to reduce the neutron speed to a value that increases the probability of fission occurring (graphite and heavy watter)
• Reflector : This completely surrounds the reactor core within the thermal shielding arrangement and helps to bounce the neutrons back to the core
• Shielding: This helps to give protection from radioactive product
• Coolant : This is used to transfer the heat generated by the reactor to the steam generator
• Most smaller atoms produced by the fission process are fission products (xenon, krypton, iodine, cesium)
• These products are radioactive and will undergo radioactive decay. Most decay quickly and will be gone within several days. Some, however, remain in the nuclear fuel for many years, and must be contained to prevent injury to the public.

ADVANTAGES

• Nuclear power generation does emit relatively low amounts of carbon dioxide (CO2). The emissions of green house gases and therefore the contribution of nuclear power plants to global warming is therefore relatively little.
• This technology is readily available, it does not have to be developed first.
• It is possible to generate a high amount of electrical energy in one single plant