On the Reconstruction of Local Homogeneous Neutron Flux and Current Distributions of Light Water Reactors from Nodal Schemes

For nodal light water reactor calculations, the reconstruction of local multigroup neutron flux and current distributions within a node is discussed. Interpolation schemes that exploit the typical behavior of multigroup neutron spectra are proposed. These spectral interpolation schemes will be seen to be more accurate than the usual polynomial approaches. They reduce the error of pin power interpolation to that of fast flux interpolation. Thus the accuracy of one node per assembly calculations is considerably enhanced. The improvement is demonstrated by several benchmark problems.