Nuclear energy is the energy that holds together the nucleus of an atom . There are two processes by which nuclear energy is released: nuclear fission and nuclear fusion .
Nuclear fission is the process of splitting the nucleus of an atom into two smaller nuclei. This process releases a large amount of energy . Nuclear power plants use fission of uranium -235 to produce energy .
Nuclear fusion is the process of combining the nuclei of two atoms to form a heavier nucleus . This process also releases a large amount of energy . Fusion is the process that powers the sun and other stars , but it has not yet been effectively harnessed for energy production on Earth .
Advantages of Nuclear Energy Low Greenhouse Gas Emissions: Nuclear power plants produce very low amounts of greenhouse gases compared to fossil fuel plants . High Energy Density : Nuclear energy has a very high energy density , meaning that a small amount of nuclear fuel can produce a large amount of energy . Reliable Power Source: Nuclear power plants can produce a continuous and reliable source of energy , unlike some renewable energy sources. Disadvantages of Nuclear Energy Nuclear Waste: The spent fuel from nuclear reactors is highly radioactive and needs to be carefully stored for thousands of years . Potential for Accidents: Nuclear accidents, such as the Chernobyl and Fukushima disasters, can have catastrophic consequences. High Initial Cost: Building nuclear power plants requires a significant initial investment. Study Guide Key Concepts What is nuclear energy ? What are the processes by which nuclear energy is released? What are the advantages and disadvantages of nuclear energy ? Key Terms Nuclear fission Nuclear fusion Radioactive waste Nuclear reactor Practice Questions Describe the process of nuclear fission and its role in nuclear power plants . What are the main advantages and disadvantages of nuclear energy ? Explain the difference between nuclear fission and nuclear fusion . .