Question

The operation of a nuclear reactor is said to be critical when the value of neutron multiplication factor \( K \) is

• A. \( K = 0 \)
• B. \( K > 1 \)
• C. \( K = 1 \)
• D. \( 0 < K < 1 \) \bigskip

Hint:

In nuclear reactors, \( K = 1 \) signifies a steady, self-sustaining reaction. It is the ideal condition for stable energy production in a reactor.

Answer 1

The Correct Option is C

\bigskip The neutron multiplication factor \( K \) in a nuclear reactor is a measure of the number of neutrons produced in one generation compared to the number in the previous generation. It is used to indicate the state of the reactor: - If \( K<1 \), the reactor is subcritical, meaning that the number of neutrons is decreasing, and the reaction is slowing down.
- If \( K = 1 \), the reactor is said to be critical, meaning that the number of neutrons is constant, and the reaction is self-sustaining.
- If \( K>1 \), the reactor is supercritical, meaning that the number of neutrons is increasing, and the reaction is becoming more intense.
Thus, the operation of a nuclear reactor is considered to be critical when the neutron multiplication factor \( K \) is equal to 1. \bigskip Thus, the correct answer is \( K = 1 \), option (3). \bigskip