5. A bare spherical reactor is made of a homogeneous mixture of heavy water and 235U, with the composition that for every uranium atom there are 2,000 heavy water atoms. Using the one-speed diffusion theory, calculate the total absorption cross-section, the thermal utilization factor, and the infinite multiplication factor for the data given below: 235 n=2.06 73=678 b a D = 3.3105 cm-1 a D = 0.87 cm Pesc = 0.6 D20 = 0.001 b