Nuclear Power and Electrical Generation

Nuclear Energy - General

• Nuclear power is a significant source of electricity worldwide.

• As of 2025, nuclear power accounted for 18% of global electricity generation.

• Nuclear power offers reliable energy without greenhouse gas emissions but faces challenges in waste disposal.

• There are 435 nuclear reactors in operation globally.

• The United States operates 101 nuclear reactors, which contribute 20% of the nation's electricity.

• Nuclear power has the lowest fuel costs compared to other non-renewable energy sources.

World Electricity Production (2025)

The distribution of world electricity production in 2025 was as follows:

• Renewables: 1%

• Hydro: 19%

• Coal: 37%

• Nuclear: 18%

• Gas: 15%

• Oil: 10%

Nuclear Power

• Nuclear power is generated from the energy released when atoms are split.

• Most nuclear reactors use fuel rods composed of uranium oxide pellets.

• Nuclear power is utilized to produce electricity.

• Nuclear power generation does not emit greenhouse gases.

• A nuclear power plant includes:

  • Reactor: where nuclear fission occurs.

  • Steam generator: uses heat from the reactor to boil water.

  • Turbine: converts steam energy into mechanical energy.

  • Generator: transforms mechanical energy into electrical energy.

  • Cooling system: removes excess heat to maintain safe temperatures.

Nuclear Fission

• Nuclear fission is the process of splitting an atom's nucleus into smaller nuclei, releasing energy.

• Uranium-235 (^{235}U) is commonly used due to its ability to undergo fission easily.

• Chain Reaction:

  • Neutrons released during fission strike other ^{235}U atoms, sustaining the reaction.

  • Control rods absorb neutrons to control the reaction rate.

• Energy Release:

  • The energy released from fission heats water, producing steam that drives turbines.

Nuclear Reactor Components

• Fuel Rods:

  • Contain enriched uranium pellets ( UO_2 ).

  • Arranged in assemblies within the reactor core.

• Control Rods:

  • Made of neutron-absorbing materials like boron or cadmium.

  • Regulate the fission rate by absorbing neutrons.

• Moderator:

  • Usually water or graphite.

  • Slows down neutrons to increase the probability of fission.

• Coolant:

  • Typically water or gas.

  • Removes heat from the reactor core.

• Shielding:

  • Concrete and steel structures that prevent radiation leakage.

Types of Nuclear Reactors

• Pressurized Water Reactors (PWR):

  • Use high-pressure water to prevent boiling in the reactor core.

  • Most common type globally.

• Boiling Water Reactors (BWR):

  • Produce steam directly within the reactor core.

• Heavy Water Reactors (HWR):

  • Use heavy water (D_2O) as a moderator.

  • Found in Canada (CANDU reactors).

Safety Measures

• Redundant Safety Systems:

  • Multiple backup systems to prevent accidents.

• Containment Structures:

  • Designed to contain radioactive materials in case of a reactor breach.

• Emergency Core Cooling Systems (ECCS):

  • Provide cooling to the reactor core in emergencies.

• Regular Inspections and Maintenance:

  • Ensure all systems function correctly.

Advantages of Nuclear Power

• Low Greenhouse Gas Emissions:

  • Nuclear power plants do not emit greenhouse gases during operation.

• High Power Output:

  • A single nuclear plant can generate a large amount of electricity.

• Reliability:

  • Nuclear power plants can operate continuously for extended periods.

• Low Fuel Costs:

  • Uranium is relatively inexpensive compared to fossil fuels.

Disadvantages of Nuclear Power

• Nuclear Waste Disposal:

  • Spent nuclear fuel remains radioactive for thousands of years, requiring long-term storage solutions.

• Risk of Accidents:

  • Although rare, accidents can release radioactive materials into the environment.

• High Initial Costs:

  • Building nuclear power plants requires significant investment.

• Security Concerns:

  • Nuclear materials must be protected to prevent theft or sabotage.