CANDUs run on natural uranium but get about 1/10th as much energy out of each kg of fuel than a LWR. So it's much more of a wash. Not a factor of 10. Check the

CANDUs run on natural uranium but get about 1/10th as much energy out of each kg of fuel than a LWR. So it's much more of a wash. Not a factor of 10. Check the average discharge burnup.