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Grade upto college level Modern Physics

In a nuclear reaction 235U undergoes fission liberating 200 MeV of energy. The reactor has a 10% efficiency and produces 1000 MW power. If the reactor is to function for 10 years, find the total mass of uranium required.

Profile image of Amit Saxena
12 Years agoGrade upto college level
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1 Answer

Profile image of Navjyot Kalra
12 Years ago
Hello Student,
Please find the answer to your question
The formula for η of power will be
η = P­out / Pin
∴ Pin = Pout / η = 1000 x 106 / 0.1 = 1010 W
Energy required for this power is given by
E = p x t
= 1010 x 86, 400 x 365 x 10
= 3. 1536 x 1018 J
200 x 1.6 x 10-13 J of energy is released by 1 fission
∴ 3.1536 x 1018 J of energy is released by
3.1536 x 1018 / 200 x 1.6 x 10-13 fission
= 0.9855 x 1029 fission
= 0.985 x 1029 of U235 atoms.
6.023 x 1023 atoms of Uranium has
235 x 0.9855 x 1029 / 6.023 x 1023 g = 38451 kg
Thanks
Navjot Kalra
askIITians Faculty