Boron rods are used in nuclear reactor as

Options

A. moderator
B. control rods
C. coolant
D. protective shield

Answer

**Step-by-Step Solution:**

1. **Understanding the Role of Boron Rods:**
- In a nuclear reactor, the primary function is to initiate and control a nuclear fission chain reaction. This reaction involves the splitting of atomic nuclei, which releases a significant amount of energy.

2. **Identifying the Function of Control Rods:**
- Control rods are essential components in a nuclear reactor. Their main purpose is to manage the rate of the fission reaction. If the reaction proceeds too quickly, it can lead to overheating and potential reactor failure.

3. **Material Properties of Boron:**
- Boron is chosen for control rods because it has the ability to absorb neutrons effectively. Neutrons are the particles that initiate the fission process when they collide with fissile material (like uranium or plutonium).

4. **Mechanism of Action:**
- When the boron rods are inserted into the reactor core, they capture neutrons. By absorbing these neutrons, boron rods decrease the number of neutrons available to sustain the fission reaction. This leads to a reduction in the reaction rate.

5. **Conclusion:**
- Therefore, boron rods are used in nuclear reactors as control rods to regulate the fission process by absorbing neutrons without undergoing fission themselves.

**Final Answer:**
Boron rods are used in nuclear reactors as control rods.

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