Before revision: Contributing effects Doppler broadening Increased thermal motion of atoms within the fuel results in a broadening of resonance capture cross-section peaks, resulting in an increased neutron capture URL Thermal expansion Thermal expansion of the fuel at higher temperatures results in a lower density which reduces the likelihood of a neutron interacting with the fuel.
After revision: rate in the non-fissile portions of the fuel, resulting in an overall reduction of neutronContributing effects Doppler broadening Increased thermal motion of atoms within the fuel results in a broadening of resonance capture cross-section peaks, resulting in an increased neutron capture URL Thermal expansion Thermal expansion of the fuel at higher temperatures results in a lower density which reduces the likelihood of a neutron interacting with the fuel.