Working Paper Article Version 1 This version is not peer-reviewed

A Transport Corrected SP3 Solver Based on Nodal Expansion Formulation for Equivalent Core Calculations

Version 1 : Received: 30 August 2021 / Approved: 3 September 2021 / Online: 3 September 2021 (08:12:14 CEST)

How to cite: Xu, Y.; Hou, J.; Ivanov, K. A Transport Corrected SP3 Solver Based on Nodal Expansion Formulation for Equivalent Core Calculations. Preprints 2021, 2021090050 Xu, Y.; Hou, J.; Ivanov, K. A Transport Corrected SP3 Solver Based on Nodal Expansion Formulation for Equivalent Core Calculations. Preprints 2021, 2021090050

Abstract

The Simplified Spherical Harmonic (SPN) approximation was first introduced as a three-dimensional (3-D) extension of the plane-geometry Spherical Harmonic (PN) equations. A third order SPN (SP3) solver, recently implemented in the Nodal Expansion Method (NEM), has shown promising performance in the reactor core neutronics simulations. This work is focused on the development and implementation of the transport corrected interface and boundary conditions in NEM SP3 solver, following recent published work on the rigorous SPN theory for piecewise homogeneous regions. A streamlined procedure has been developed to generate the flux zero and second order/moment discontinuity factors (DFs) of the generalized equivalence theory to eliminate the error introduced by pin-wise homogenization. Moreover, several color set models with varying size and configuration are later explored for their capability of generating DFs that can produce results equivalent to that using the whole-core homogenization model for more practical implementations. The new developments are tested and demonstrated on the C5G7 benchmark. The results show that the transport corrected SP3 solver shows general improvements to power distribution prediction compared to the basic SP3 solver with no DFs or only zero order/moment DFs. The complete equivalent calculations using the DFs can almost reproduce transport solutions with high accuracy. The use of equivalent parameters from larger size color set models show better prediction in the whole-core calculations. By coupling different color set models DFs can offer the best accuracy at both eigenvalues and power distributions.

Keywords

Transport Corrected SP3; Nodal Expansion Method; Generalized Equivalence Theory; Discontinuity Factors

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our diversity statement.

Leave a public comment
Send a private comment to the author(s)
Views 0
Downloads 0
Comments 0
Metrics 0


×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.
We use cookies on our website to ensure you get the best experience.
Read more about our cookies here.