Moderators and control rods are key components of a commercial nuclear fission reactor.

Select the correct function for each of the following components:

1. Moderator
2. Control rods

Choose from the list of functions below:

• slows down fast-moving neutrons to thermal speeds
• absorbs neutrons to regulate the rate of the chain reaction
• transfers thermal energy from the reactor core
• shields the environment from highly ionizing radiation

Describe the process of induced nuclear fission inside a reactor, explaining how a chain reaction can be sustained.