Identify a heavy isotope commonly used as fuel in commercial nuclear fission reactors.
Explain what is meant by a self-sustaining fission chain reaction.
Explain why the high-level waste containing fission products must be shielded and stored securely in deep geological repositories for thousands of years.
Many nuclear reactors use pressurized water or heavy water as a moderator. Describe the main purpose of the moderator in the reactor core.
The power output of a reactor is controlled by adjusting the position of control rods. Explain how withdrawing the control rods affects the rate of nuclear fission.
An advanced gas-cooled nuclear reactor is cooled by circulating helium gas.
The helium enters the reactor core at a temperature of 220 ∘C220\ ^\circ\text{C}220 ∘C.
Convert this entry temperature into kelvin.
The helium gas enters the core at a pressure of 4.50 MPa and leaves the core at a temperature of 950 K.
Calculate the pressure of the helium gas as it leaves. Assume that the volume of the gas remains constant during its passage through the core.
22 exam-style questions on Edexcel IGCSE Physics Fission and fusion. Each one has a worked solution and a mark scheme showing where the marks go.