3.8.1.8
Nuclear fuel is enriched uranium: U-238 mixed with fissile U-235
Nuclear Energy & Binding Energy — AQA A-Level Physics
- U-235 is the fissile isotope — it undergoes induced fission when it absorbs a thermal neutron.
- U-238 absorbs fission neutrons without undergoing fission, helping to control the reaction rate.
- Enriched uranium has a higher proportion of U-235 than occurs naturally.
- Fuel rods are handled remotely by machines to minimise worker exposure.
- The reactor core is surrounded by thick lead or concrete shielding to prevent radiation leakage.