As far as I understand plutonium production is mainly a function of the spesific burn-up. A low burn-up of under 1000 MWd/tU is prefered to produce weapongs-grade plutonium. The higher the burn-up the more pu-240 and other plutonium isotopes that makes production of weapons a bit more difficult and increases the risk of a fizzle. How does the enrichment level play into this? A reactor fueled with natural uranium will have more u-238 available for neutron capture than a reactor fueled with LEU. Will a LEU reactor produce a better/worse composition of plutonium isotopes compared to a NU reactor if their burn-up levels were equal?