Nuclear Reactors Flashcards
All 6 cards in this deck
What is meant by a controlled chain reaction?
On average only one neutron from each fission goes on to cause another fission, so the number of fissions per second stays constant.
What is the job of the moderator in a nuclear reactor?
It slows down the fast neutrons so they are more likely to be absorbed and cause further fission.
What is the job of the control rods in a nuclear reactor?
They absorb neutrons, so fewer neutrons are available to cause fission.
True or false? The control rods slow down the neutrons in a nuclear reactor.
False. The moderator slows neutrons down; the control rods absorb them.
What are the steps by which pushing the control rods further in slows the chain reaction?
e.g. the reactor core is getting too hot
- The rods are lowered further into the core.
- They absorb more of the neutrons.
- Fewer neutrons are available, so fewer fissions happen each second and less energy is released.
True or false? Removing the control rods from the core speeds up the chain reaction.
True. Fewer neutrons are absorbed, so more neutrons cause fission.