Study on the conservative factors for burnup credit criticality calculation

When applies the burnup credit technology to perform criticality safety analysis for spent fuel storage or transportation problems,it is important for one to confirm that all the conditions adopted are adequate to cover the severest conditions that may encounter in the engineering applications.Taking the OECD/NEA burnup credit criticality benchmarks as sample problems,we study the effect of some important factors that may affect the conservatism of the results for spent fuel system criticality safety analysis.Effects caused by different nuclides credit strategy,different cooling time and axial burnup profile are studied by use of the STARBUCS module of SCALE5.1 software package,and related conclusions about the conservatism of these factors are drawn.