SP₃ Solution versus Diffusion Solution in Pin-by-Pin Calculations and Conclusions Concerning Advanced Methods

Abstract

Opportunities for and limitations of the use of the SP₃ solution instead of the diffusion solution are given and discussed. Due to existing limitations, the use of a hybrid method consisting of nodal full core calculations coupled with an advanced transport solution based on the current coupling collision probability method with an orthonormal flux expansion is proposed. The method seems to be promising compared to adaptive mesh using refined geometry but without refined detail information, which is deleted by the homogenization process and compared to brute force full core pin-by-pin using advanced transport solvers.

Keywords:

• SP₃ approximation
• diffusion approximation
• current coupling collision probability
• transport equation