This deep dive covers Nuclear Power Stations within Nuclear Fission & Fusion for GCSE Physics. Revise Nuclear Fission & Fusion in Atomic Structure for GCSE Physics with 13 exam-style questions and 25 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 7 of 18 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 7 of 18
Practice
13 questions
Recall
25 flashcards
🏭 Nuclear Power Stations
How they work:
- Fuel rods — contain uranium-235 (or plutonium-239)
- Moderator — slows down neutrons so they can cause fission (graphite or water)
- Control rods — absorb neutrons to control the rate of reaction (boron or cadmium)
- Coolant — transfers thermal energy away (water or CO₂)
- Heat boils water → steam drives turbines → generators produce electricity
Controlling the reaction:
- Lower control rods → absorb more neutrons → reaction slows down
- Raise control rods → absorb fewer neutrons → reaction speeds up
- Aim: maintain exactly one fission per fission (critical)
Quick Check: What is the purpose of the moderator in a nuclear reactor?
The moderator (graphite or water) slows down the fast neutrons released by fission. Slow neutrons are much more likely to be absorbed by uranium-235 nuclei and trigger further fission reactions.