Final answer:
A boiling water reactor (BWR) uses uranium fuel rods, water as a neutron moderator, and control rods, usually made of boron, to regulate the nuclear reaction. Fast Neutron Reactors (FNR) differ by not using a moderator, employing fast neutrons for fission reactions in certain actinides. Both reactors generate heat to create steam for electricity production and have safety measures such as control rods for regulating the reaction.
Step-by-step explanation:
A boiling water reactor (BWR) uses water as a neutron moderator and a thermal conveyance medium. In a BWR, nuclear fuel, such as uranium, is structured into fuel rods to provide a large surface area. The water circulates between these rods, slowing down neutrons and carrying away the heat generated from the fission of uranium-235 (235U). Control rods, usually containing boron, regulate the reactor's activity by being inserted from the top into the reactor core. These control rods can absorb neutrons rapidly, thereby controlling the nuclear chain reaction. In emergencies, an additional set of control rods can be dropped quickly into the core to halt the reaction immediately.
A Fast Neutron Reactor (FNR), not described in detail in the provided information, differs from BWR in that it does not use a moderator to slow down the neutrons. Instead, it operates using fast neutrons to sustain the chain reaction, with the fast neutrons resulting in a higher probability of fission in certain actinides, leading to different reactor design and fuel requirements.
Both types of reactors generate heat through the fission of uranium, which is then used to create steam. The steam is directed through turbines to generate electricity. In BWRs, the steam is produced directly in the reactor vessel, whereas FNRs typically involve a heat exchanger system due to the absence of a moderator. Both designs incorporate extensive safety measures including control rods and emergency shutdown capabilities.