Analysis of the PHWR benchmark transient using a high-order spherical harmonics-nodal collocation method and treatment of rod cusping effect

[EN] We develop and validate node homogenization methods, based on one and three-dimensional node equivalent problems, that improve the volume weighted method for the treatment of the rod cusping effect. The numerical implementation of these techniques in a numerical approach based on general spherical harmonics, nodal collocation method, for arbitrary odd order ¿¿, and fully implicit time discretization, is verified on the AECL-7236 PHWR benchmark transient, showing the validity and convergence of the P1 and P3 approximations and the ability of the method to give accurate results for the relative power and scalar flux when a coarse spatial mesh combined with advanced homogenization techniques is used.