Chain reactions and Nuclear reactors (4.2) Flashcards
What is a chain reaction
A self sustaining fission reaction due to a release of neutrons
What are the three enrichment techniques to enrich U-238
ultra centrifuge, electromagnetic and gaseous diffusion
What are the factors affecting explosive ability of fissile material
Shape
Purity
Size
Flat samples with large surface area’s result in neutrons escaping into air
Spherical samples will spontaneously explode as greater proportion of neutrons remain to sustain chain reaction (N.A)
What is critical mass
The minimum amount of enriched fissile material in the shape of a sphere that leads to a sustained chain reaction is known as the critical mass
Subcritical mass
Fissionable material in insufficient quantity or improper geometric configuration to sustain a chain reaction
Briefly describe the function of the following nuclear reactor parts
Fuel rod
Moderator
Control Rods
Coolant
Radiation shield
fuel rod - Long thin rod containing pellets of enriched material
Moderator - a material that Regulates the speed of neutrons in a chain reaction contained within the core
Control rods - Control the number of neutrons involved in a fission reaction made of boron
Coolant - A liquid to absorb heat energy produced by fission reactions
Radiation Shield - A thick concrete or graphite wall that prevents neutrons from escaping the reactor
What is a moderator and what is used as a moderator
Moderator - a material Regulates the speed of neutrons in a chain reaction contained within the core
usually heavy water (water w deuterium)
Graphite
Carbon dioxide
Wateron
What is a fast breeder reactor (ASK)
Explain the how a nuclear reactor works (5 marks)
Explain out loud or in dot points
See page 102 summary
A nuclear reactor uses uranium fuel containing 3-4% U-235 (N.A)
