Nuclear power Flashcards
How can fission can be induced in certain elements such as uranium-235?
by firing a thermal
neutron into the uranium nucleus causing it to become extremely unstable.
How is fission used in nuclear reactors?
Rods of uranium-235 absorb neutrons and
become unstable and then split into two daughter
nuclei. It also releases 2/3 more neutrons. These
then go on to be reabsorbed by another
uranium-235.
What is the purpose of a moderator?
● To slow down the neutrons so they travel slow
enough to be absorbed by the uranium.
● They do this through elastic collisions between
the moderator and the nucleus.
Why is control rods essential for a
nuclear power station?
● They stop the chain reaction from being out of control.
● They absorb neutrons so that only 1 of the neutrons released
in each reaction can go on to be absorbed by another
uranium.
● If not then the nuclear reactor would overheat as too many
reactions would happen at once.
Is Boron used as a control rod or a
moderator?
Moderator
Give an example of a material that can
be used as a moderator?
Water
What is the purpose of using water as a
coolant?
It allows heat from the nuclear reactor to escape,
which stops the reactor from overheating.
Which waste products from a nuclear reactor cause
the highest risk?
Spent fuel rods.
How is high-level waste disposed of?
● They are first stored in cooling ponds
● Then they are put in sealed steel containers
and put deep underwater.
What is low level waste contained in?
They are sealed in containers and put
underground until it is safe again.
what is a chain reaction?
When fission reactions produce more neutrons which then induce other nuclei to fission
