Absorption: Rods of radioactive waste that are highly active are stored in cooling ponds of purified water. Usually, the rods are stored 20 feet below the surface of the water. We wish to calculate the neutron flux that reaches the surface the water. The total cross- section for an incident, room-temperature neutron onto a 1H nucleus is approximately 35 barns. The total cross-section for an incident, room-temperature neutron onto an oxygen nucleus is approximately 4 barns. A. Calculate the molecular number density of water.
B. Calculate the number density of hydrogen nuclei and the number density of oxygen nuclei.
C. Calculate the macroscopic cross-section (Z) for an incident, room temperature neutron passing through the water.
D. Calculate the mean free path ( (x) ) of a room temperature neutron in water.
E. Calculate the fraction of the radiation emitted from the rods that reach the surface of the water (1(x)/10).