Science and Technology · Nuclear Energy

With reference to the Prototype Fast Breeder Reactor, consider the following statements: I. Fast breeder reactors primarily rely on slow (thermal) neutrons moderated by heavy water to sustain the chain reaction. II. In breeder reactors, fertile isotopes such as Uranium-238 can be converted into fissile material through neutron absorption. III. Liquid sodium is used as a coolant in fast breeder reactors because it efficiently transfers heat without significantly slowing down neutrons. IV. Attainment of 'criticality' in a nuclear reactor implies that neutron production and neutron losses are in equilibrium, enabling a self-sustaining chain reaction. How many of the statements given above are correct?