I'm pretty sure that conventional reactor split around as much fuel as the U-235 content.
For conventional reactors it is around 3% and you are left with around 3% fission products.
Natural uranium has around 0.7% U-235. But I0m pretty sure that you would enrich the uranium befor you send it to mars. The 16TJ/kg is for enriched uranium with 20% U-235 content.
Anyway, energy density of nuclear fuel is extremly high. Even if you pay 10000 USD/kg for the transport of fuel to mars, you'd pay around 1 cent/kwh for the transport.
For conventional reactors it is around 3% and you are left with around 3% fission products.
Natural uranium has around 0.7% U-235. But I0m pretty sure that you would enrich the uranium befor you send it to mars. The 16TJ/kg is for enriched uranium with 20% U-235 content.
Anyway, energy density of nuclear fuel is extremly high. Even if you pay 10000 USD/kg for the transport of fuel to mars, you'd pay around 1 cent/kwh for the transport.