Question

A country consumes 1735 GWh per year. All of the energy comes from nuclear power plants, which at the moment utilize uranium. They are evaluating if they should make modifications to use thorium instead. Based on the price of raw material per year, which one would you recommend they use?

Information: Uranium – 0.02 g lost per 235 g of material, US$20/kg

Thorium – 0.03 g lost per 229 g of material, US$35/kg

Answer: According to the calculations, uranium is still the best choice economically, they should continue to use uranium.

Prices: Uranium – US$16332.5

Thorium – US$18568.1

Answer 1

per 235 g lost = 0.02 g = 2*10^-5kg
E = deltam * c^2
= (2*10^-5)*(3*10^8)^2
=1.8*10^12 J

235 g will produce = 1.8*10^12 J

Energy required = 1735 GWh
= 1735*10^9 W * 3600 s
= 6.246*10^15 J
U-235 required = 235 g * 6.246*10^15 / (1.8*10^12) = 815450 g = 815.45 kg
Price for U-235 = 20*815.45 = $16309

per 229 g lost = 0.03 g = 3*10^-5kg
E = deltam * c^2
= (3*10^-5)*(3*10^8)^2
=2.7*10^12 J

229 g will produce = 2.7*10^11 J

Th required = 229 g * 6.246*10^15 / (2.7*10^12) = 529753 g = 529.753 kg
Price for Th = 35*529.753 = $18541

uranium is still the best choice economically, they should continue to use uranium.