Nuclear Engineering Principles 4

Which isotopes are fissile?

• Pu-239

• U-233

• U-235

• U-238

Which isotopes are fissionable?

• U-238

• U-233

• U-235

• Pu-239

For an isotope to undergo fission, the critical energy must be…

• Higher than the binding energy

• Lower than the binding energy

• The same as the binding energy

• Double the binding energy

Th-232 has a critical energy of 7.5 MeV and a binding energy of 5.4 MeV. How much energy does an incoming neutron need to have for fission to occur?

• 5.4 MeV

• 7.5 MeV

• 2.1 MeV

• 12.9 MeV

Why can all of the energy from a fission reaction not be recovered in a reactor?

• Fission products are too high in energy

• Some energy is lost as antineutrinos

• Photoneutrons are produced

• Radioactive decay processes absorb some of the energy

Which type of neutrons are emitted only from fission fragments?

• Prompt neutrons

• Delayed neutrons

• Fast neutrons

• Thermal neutrons

Reactors must always stay _____ for prompt neutrons.

• Critical

• Supercritical

• Subcritical

• Equal

What is a nuclear reaction cross section?

• The likelihood of a reaction happening.

• The speed of the reaction.

• The amount of energy released from the reaction.

• The rate of the reaction.

Which are the most common fuels used for nuclear fusion?

• Uranium and plutonium

• Hydrogen and nitrogen

• Deuterium and tritium

• Carbon and oxygen

How does a tokamak reactor confine plasma?

• Using magnetic fields

• Using electric fields

• Using strong forces

• Using charged particles