HIGHER ORDER ACCURATE K-EIGENVALUE SENSITIVITY ESTIMATION USING THE COMPLEX-STEP DERIVATIVE METHOD

摘要

This paper employs the complex-step derivative method (CDM) to calculate the k-eigenvaluesensitivity with respect to nuclear cross-section in reactor applications. The CDM utilizes aTaylor series expansion in the complex-plane whereby the imaginary part of the complexsolution space represents the gradient. This numerical approach offers many advantages overconventional techniques such as first-order perturbation theory. A one-group one-dimensionalk-eigenvalue problem is used in the paper as a numerical example to demonstrate thefeasibility of the CDM in reactor problems. The preliminary results from the numericalexample justify the viability and higher accuracy of the CDM through a one-to-onecomparison to the results from the direct perturbation approach.