Is 3-D Resonance Self-shielding Calculation Necessary for the Direct Transport Method in LWR Analysis?

摘要

The necessity of performing the resonance self-shielding calculation in 3-D geometry for direct transport problem is discussed by investigating three typical LWR applications. The results show that the heterogeneities of axial boundary leakage, distributed moderator densities (BWR) and partially inserted control rod do not result in significant differences of the reaction rate and eigenvalue between 2-D resonance calculation with axial reflective boundaries and explicit 3-D resonance calculation. Therefore, 2-D resonance calculation should be sufficient for the direct transport calculation of the regular LWR applications.