Parametric study of the influence of heterogeneous boron concentration and coolant density on cross section generation in BWRs

Paper in proceeding, 2008

In this paper, we investigate the effect of heterogeneous boron concentration and coolant density distribution on nodal macroscopic cross sections, which could potentially arise in an Anticipated Transient Without Control rods of a boiling water reactor. All calculations are made with the 2-D transport code PHOENIX4. Full core simulators, such as POLCA7, often have simple models for handling such heterogeneities with the basic requirement that conservative results are obtained simulating such core conditions. We have found that this is not always the case and that the errors can potentially be quite high.