Application of the hierarchical domain decomposition boundary element method to the simplified P3 equation

► The hierarchical domain decomposition boundary element method is applied to the SP3 equation. ► A two-dimensional one-group anisotropic-scattering problem is solved with this method. ► This method results in good agreement with the reference for eigenvalue and neutron flux. ► This benchmark result suggests that this method is suitable for application to the SPN equation.