Nuclear Reactor Simulator
Classroom worksheet · Interactive simulation: https://lkforge.com/tools/physics/nuclear/
Name: Date:
Learning objectives
- Explain nuclear fission and chain reactions.
- Describe how control rods regulate a reactor.
- Define criticality.
Variables to change
- Control rod position
- Neutron population
- Fuel enrichment
Procedure
- Start the reactor and watch the neutron population and power.
- Withdraw the control rods and observe the reaction rate rise.
- Insert the control rods and observe it fall.
Observations
Record how neutron population/power responds to control rod position.
Questions
- What is nuclear fission?
- What is a chain reaction?
- What does "critical" mean (k = 1)?
- How do control rods work?
- What happens if k > 1?
Answer key (instructors)
- 1. A heavy nucleus splitting into lighter nuclei, releasing energy and neutrons.
- 2. Neutrons from one fission trigger further fissions, sustaining the process.
- 3. Each fission causes exactly one further fission on average, so the reaction is steady.
- 4. They absorb neutrons; inserting them slows the reaction, withdrawing them speeds it up.
- 5. The reaction rate grows (supercritical); reactors are kept at k ≈ 1 for steady output.
Fission splits heavy nuclei, releasing energy and neutrons that can trigger more fissions — a chain reaction. A reactor is held critical (k = 1) for steady power; neutron-absorbing control rods raise or lower the reaction rate.