Nuclear Physics 8

How do neutrons diffuse in a reactor?

• From low to high concentration

• From high to low concentration

• From top to bottom

• From bottom to top

What happens to the diffusion coefficient if the moderator temperature is increased?

• It increases slightly

• It stays the same

• It decreases

• It increases a lot

What is the measure of how far neutrons travel in a straight line before they are absorbed?

• Mean free path

• Migration length

• Diffusion length

• Diffusion area

What is the measure of how far neutrons travel in a straight line during the slowing down (thermalisation) process?

• Migration length

• Diffusion area

• Diffusion length

• Mean free path

What is geometrical buckling a measure of?

• Neutron absorption

• Neutron leakage

• Neutron thermalisation

• Neutron speed

When is geometrical buckling equal to material buckling?

• In a sub critical reactor

• In a critical reactor

• In a supercritical reactor

• In a zero power reactor

Which type of fuel loading pattern is more favourable?

• In-out

• Out-in

• Out-out

• In-in

Which of these causes a more even power distribution/flattens neutron flux?

• Negative feedbacks

• Neutron reflectors

• Control rods

• Fuel depletion

What happens to the neutron flux in a reactor core if thermal power is increased?

• It shifts from top to bottom

• It shifts from bottom to top

• It stays the same

• It increases

What happens to the neutron flux around xenon-135?

• It decreases

• It increases

• It stays the same

• It moves