Nuclear Power (HL) (DP IB Environmental Systems & Societies (ESS))

Nuclear Power

What is nuclear power?

• Nuclear power is a method of generating electricity using the energy released from nuclear reactions

  • Specifically, a type of reaction called nuclear fission

• Unlike solar or wind, nuclear power uses finite resources, such as uranium and plutonium

  • These resources will eventually run out

  • Nuclear is therefore a non-renewable energy source

How does nuclear power work?

Nuclear fission

• Fission reaction:

  • Nuclear fission is the process of splitting the nucleus of heavy atoms like uranium or plutonium

    • This process releases very large amounts of energy

    • This energy is used to heat water

    • The steam produced is used to turn turbines and generate electricity

• Common fuels:

  • Uranium-235: the most commonly used fuel in nuclear reactors

  • Plutonium-239: used in some reactors, but less common than uranium

• The nuclear reactor is:

  • The part of the power station that provides thermal energy from fission chain reactions

• The boiler is:

  • The part of the power station that uses thermal energy to boil water to create steam

• The turbine is:

  • The part of the power station that uses steam to transfer thermal energy into kinetic energy

• The generator is

  • The part of the power station that transfers kinetic energy into electrical energy

• The condenser is:

  • The part of the power station that cools the steam back into water

Advantages of nuclear power

1. Constant, low-cost energy

• High efficiency:

  • Once built, nuclear power stations can produce large amounts of energy consistently over decades

• Low operational costs:

  • After the high initial construction costs, nuclear plants have relatively low running costs

2. Low-carbon energy

• Minimal greenhouse gas emissions:

  • Unlike coal or gas, nuclear power does not emit CO₂ during electricity generation

  • This is why nuclear is considered important in efforts to combat climate change

    • E.g. over 40% of Sweden's electricity comes from nuclear power, contributing to the country’s low-carbon energy mix

Disadvantages of nuclear power

1. Environmental concerns

• Uranium mining:

  • Extracting uranium can lead to habitat destruction and water pollution

  • Mining also produces radioactive waste

• Thermal pollution:

  • Nuclear power stations often use water for cooling

  • Discharge of heated water into nearby rivers or lakes can alter water temperature and chemistry, affecting local ecosystems

2. Nuclear accidents

• Risk of accidents:

  • Nuclear accidents, though rare, can have catastrophic consequences:

    • E.g. Chernobyl (1986): a reactor explosion led to widespread contamination

    • E.g. Fukushima (2011): a tsunami disabled cooling systems at a nuclear plant, causing radiation leaks

3. Radioactive waste

• Long-term storage:

  • Nuclear reactors produce radioactive waste

    • This waste remains hazardous for thousands of years

    • The waste is stored in specially designed containers to shield the environment from radiation