The UFTR is observed to be on a stable period of 100 seconds. Assuming the initial power level is 10 W, 75 seconds later, the operating power level will be approximately:

The UFTR is observed to be on a stable period of 100 seconds. Assuming the initial power level is 10 W, 75 seconds later, the operating power level will be approximately:

• A. 12 W
• B. 15 W
• C. 18 W
• D. 21.2 W

Answer: (D)

Power in a reactor with a stable period changes exponentially over time, with the period defined as the time needed for the power to rise by a factor of e. So the power at time t is P(t) = P0 * exp(t / T_p), where T_p is the period. Here, the stable period is 100 seconds, the initial power is 10 W, and the elapsed time is 75 seconds. Compute the growth factor: exp(75/100) = exp(0.75) ≈ 2.117. Multiply by the initial power: 10 W * 2.117 ≈ 21.2 W. So the operating power level after 75 seconds is about 21.2 W.

Power in a reactor with a stable period changes exponentially over time, with the period defined as the time needed for the power to rise by a factor of e. So the power at time t is P(t) = P0 * exp(t / T_p), where T_p is the period.

Here, the stable period is 100 seconds, the initial power is 10 W, and the elapsed time is 75 seconds. Compute the growth factor: exp(75/100) = exp(0.75) ≈ 2.117. Multiply by the initial power: 10 W * 2.117 ≈ 21.2 W.

So the operating power level after 75 seconds is about 21.2 W.