Nuclear safety aspectsAQA A-Level Physics: Mind map

Exam questions on Nuclear safety aspects

1. A nuclear power station uses fuel rods containing enriched uranium-235. The rods are replaced every 18 months. The spent fuel removed from the reactor is hot and highly radioactive.
   Explain why spent fuel rods are stored under water in cooling ponds for several years.2 marks
2. A thermal nuclear reactor is operating at a steady rate when sensors detect an earthquake and an emergency shutdown is started.
   Explain how inserting the control rods stops the chain reaction.2 marks
3. A nuclear power station produces three types of waste: low-level waste (such as contaminated clothing and tools), intermediate-level waste (such as reactor components and fuel cladding) and high-level waste (spent fuel containing fission products). Caesium-137, a fission product, has a half-life of 30 years. The high-level waste also contains plutonium-239, which has a half-life of 24 000 years.
   Explain why high-level waste must be stored for much longer and more securely than low-level waste.3 marks