Utilization of heavy elements such as lead or bismuth in thermal and epithermal reactors

Abstract From the Canadian patent

Increases in reactivity can be obtained in thermal and epithermal reactors by utilizing heavy elements defined as, those elements having high inelastic scattering cross-section for high energy neutrons and low capture cross-sections such as lead and bismuth, in selected locations in the reactors to obtain a reactivity increase through the utilization of inelastic scattering reactions between fast neutrons and the heavy elements to more effectively slow down these fast neutrons. Such increases in reactivity can result in economic gains for example, in, reduction of the amounts of heavy water needed in heavy water moderated reactors and in reduction of the enrichment needed in light water …