A nuclear reactor produces a thermal power of 640 MW. Assume that each fission releases 200 MeV and take 1 eV = 1.6×10⁻¹⁹ J. If the fission rate is N×10¹⁹ s⁻¹, find N.
Physics · Nuclear physics · nuclear fission and fusion ,nuclear reactor
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Question

A nuclear reactor produces a thermal power of 640 MW. Assume that each fission releases 200 MeV and take 1 eV = 1.6×10⁻¹⁹ J. If the fission rate is N×10¹⁹ s⁻¹, find N.

G1 Physics · Accepted Answer

Thermal power is energy released per second. Energy released per fission: E(fission) = 200×10⁶×1.6×10⁻¹⁹ = 3.2×10⁻¹¹ J. Reactor thermal power: P = 640 MW = 640×10⁶ J·s⁻¹. Fission rate: rate = P ÷ E(fission) = 640×10⁶ ÷ 3.2×10⁻¹¹ = 2.0×10¹⁹ s⁻¹. Therefore N = 2.