NEET2026PhysicsChapterActual
In a nuclear fission reactor, control rods made of materials such as cadmium or boron are used primarily to:
Options
- Aslow down the fast-moving neutrons produced during fission
- Babsorb excess neutrons to regulate the power level of the reactor
- Ctransfer heat from the reactor core to the steam generator
- Dprovide the initial fast neutrons required to start the chain reaction
Correct answer
B. absorb excess neutrons to regulate the power level of the reactor
Step-by-step solution
In a nuclear fission reactor, control rods are made of neutron-absorbing materials such as cadmium or boron. Their primary function is to absorb excess neutrons produced during the fission process. By inserting or withdrawing these rods from the reactor core, the number of available neutrons is controlled, which in turn regulates the rate of the chain reaction and the power level of the reactor. Slowing down fast-moving neutrons is the function of a moderator, while transferring heat is the function of a coolant. A