Nuclear Power (fission & fusion Flashcards
What are the pros of using nuclear power
reliable
high energy density of fuel
no CO2 release so no contributions to climate change
What are the cons of using nuclear power
Nuclear waste is extremely hard to dispose of as it can remain radioactive for thousands of years
They are extremely expensive
Need high security
Uranium is non renewable
Public fear of nuclear meltdowns
What do control rods do
They are dipped into the reactor and absorb any spare neutrons slowing the chain reaction down
What fuel elements are used
Typically Uranium-235
Each nucleus gets split by neutrons to release energy
What does a moderator do
In order to do the splitting, the neutrons must move SLOWLY. Therefore the fuel rods are surrounded by a material (often graphite or ‘heavy water’) whose job it is to slow the neutrons down
What does the concrete reactor casing do
Used to
a) contain the CO2 so it gets hot
b) concrete stops radioactive radiation from the waste daughter nuclei from escaping the reactor
How does nuclear fusion work
If you fling the isotopes of hydrogen (deuterium and tritium) hard enough at each other overcoming you electrostatic repulsion, they’ll stick together to form helium and release energy.
What are the problems in using nuclear FUSION
Containment because it needs a VERY HIGH TEMPERATURE (to get the nuclei moving fast enough) and VERY HIGH DENSITY (so they hit each other often enough)
How does nuclear fission work
The nucleus of a fissionable substance splits into two smaller daughter nuclei and 3 neutrons. This event can cause other fissionable nuclei to split, producing a chain reaction of fission events
What does the heat exchanger do
Transfers thermal energy from one fluid to another without mixing the two fluids.
