DP IB Physics: SL
E: Nuclear and quantum physics
E.4 Fission
DP IB Physics: SLE: Nuclear and quantum physicsE.4 Fission
Linking questions: | |
|---|---|
| a) | In which form is energy released as a result of nuclear fission? |
| b) | How is binding energy used to determine the rate of energy production in a nuclear power plant? |
| c) | To what extent is there a role for fission in addressing climate change? (NOS) |
a) In which form is energy released as a result of nuclear fission?
- Solution:
- Nuclear fission releases energy mostly in the form of electromagnetic radiation (mainly gamma rays) and the kinetic energy of the fission fragments and neutrons.
- Although they are hard to find, some energy is also released as neutrinos.
- Figure 1 Nuclear Fission
- Kinetic Energy of Fission Fragments:
- The lighter nuclei that are left over after a nucleus splits have kinetic energy and travel quickly apart.
- Neutron Kinetic Energy:
- Neutrons, which also have kinetic energy, are released during fission.
- Electromagnetic radiation (Gamma rays):
- Gamma rays, or electromagnetic radiation, are released when fission fragments and newly formed nuclei, which are frequently in an excited state, release energy.
- Neutrinos:
- These subatomic particles, which have a very weak interaction with matter, carry away a tiny amount of the energy.
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b) How is binding energy used to determine the rate of energy production in a nuclear power plant?
- Solution:
- A nuclear power plant’s energy production rate is largely determined by binding energy.
- The change in the binding energy of the participating nuclei is directly proportional to the energy released during nuclear reactions, such as fission in nuclear reactors.
- In particular, the daughter nuclei that result from fission have a higher binding energy per nucleon than the parent nucleus.
- The power plant uses the energy that is released in response to this increase in binding energy.
- Thus, the rate of these nuclear reactions and the corresponding change in binding energy are directly related to the rate of energy production.
- Figure 2 Energy production in nuclear power plant
- Binding Energy:
- The energy that holds an atom’s nucleus together is known as binding energy. It is equivalent to the energy needed to split an atom’s nucleus into its constituent protons and neutrons.
- Binding energy and nuclear reactions:
- Nuclei undergo transformation in nuclear reactions, such as fission. A heavy nucleus, such as Uranium-235, splits into smaller nuclei during fission. Compared to the original nucleus, these smaller nuclei have a higher binding energy per nucleon.
- Energy Release:
- The energy that results from the difference in binding energy between the initial nucleus and the resultant nuclei is released. Einstein’s well-known equation,
- [math]E = mc^2[/math]
- Which converts the mass difference (mass defect) into energy, controls this energy release.
- Rate of Energy Production:
- The rate of nuclear fission reactions has a direct correlation with the rate of energy production in a nuclear power plant.
- The amount of fissile material (such as Uranium-235) present and the control rod adjustments that govern the neutron flux, which in turn affects the reaction rate, are two examples of factors that have an impact on this rate.
- Binding Energy per Nucleon:
- This idea is also crucial. It gives an indication of how stable a nucleus is. More stable nuclei have a higher binding energy per nucleon. Energy is released during fission because the products have a higher binding energy per nucleon than the reactants.
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c) To what extent is there a role for fission in addressing climate change? (NOS)
- Solution:
- Despite its controversy, nuclear fission contributes significantly to climate change mitigation by offering a sizable supply of low-carbon electricity.
- When compared to fossil fuel-based power generation, nuclear power plants avoid a significant amount of greenhouse gas emissions.
- However, due to worries about safety, waste management, and possible proliferation risks, the extent of its role is up for debate.
- Figure 3 A role for fission in addressing climate change
- ⇒ Positive contributions:
- Low Carbon Emission:
- During operation, nuclear power plants use nuclear fission to produce electricity without emitting greenhouse gases. In the battle against climate change, this is a huge advantage.
- Large-scale electricity generation:
- Nuclear power plants are a dependable baseload power source because they can generate enormous amounts of electricity. This is essential for supplying the world’s energy needs and lowering dependency on fossil fuels.
- Avoidance of Greenhouse Gas Emissions:
- The amount of CO2 that has been kept out of the atmosphere thanks to nuclear energy has already reached billions of tones, and that number keeps rising every year.
- Complementing Renewables:
- By offering a steady and dependable power source, nuclear power can be used in conjunction with intermittent renewable energy sources like wind and solar.
- ⇒ Limitations and concerns:
- Public Perception and Safety:
- The public opposes nuclear power because they are worried about safety, especially in the wake of catastrophic accidents like Chernobyl and Fukushima.
- Waste Management:
- Getting rid of nuclear waste is a long-term problem that needs to be carefully planned and handled.
- High Initial Costs:
- The high upfront costs associated with developing new nuclear power plants may prevent their widespread use.
- Not a Standalone Solution:
- Climate change cannot be resolved by nuclear power alone. It is necessary to use a variety of low-carbon energy sources, including renewables.
- Limited Flexibility:
- When it comes to adapting to changes in the demand for electricity, nuclear power plants are less flexible than other power sources.