A water-moderated reactor contains 100,000 kg of uranium dioxide enriched to an average of 2.5% by weight in 235U. The atomic ratio H/235U is 200. Calculate the approximate (spatial) average thermal neutron flux for a thermal power of 3,000 MW-thermal. For 235U at T = 300 K, the total fission cross section at 0.0253 eV is 584.4 barn