A simplified pressurized water reactor uses 20w/oU235 fuel enriched (the rest is U-238) and operates at 300MW. The initial fuel loading is 1000kg of UO2. Assume that U235 fission is the only neutron reaction taking place inside the reactor. Apply the rule of thumb that 1.3 grams of U 235 is consumed per megawatt-day of thermal energy, the enrichment level after one year is closest to