What happens to the annual fuel requirement if the enrichment level increases?

When the enrichment level of nuclear fuel increases, it indicates a higher concentration of fissile isotopes, such as U-235 in uranium fuel. This higher proportion of fissile material enhances the fuel's reactivity. Consequently, with more reactivity per amount of fuel, the reactor can achieve the same power output using less total fuel mass.

As a result, the annual fuel requirement decreases with increasing enrichment levels because the reactor becomes more efficient at extracting energy from less fuel. This is a crucial concept in nuclear reactor operation and design, as it directly affects fuel cycle economics, waste management, and resource utilization in nuclear energy generation. An increase in enrichment means that the energy produced per unit of fuel is higher, thus reducing the overall amount of fuel needed for a given period.