The Implementation of an Automated Direct Sensitivity Analysis Tool to Thermalhydraulic Codes

Abstract

The move towards probabilistic strategies and reliance on best estimate codes for thermalhydraulic (TH) analysis increases the importance of proper sensitivity and uncertainty analysis. Sensitivities can be determined using a direct analytical approach through the use of partial derivatives. Despite the high level of upfront effort required, this method, once accomplished, is applicable to almost any scenario modeled. The sensitivity system can be used separately to generate information without requiring full TH code runs. The design, methodology and application of an automated FORTRAN script that can edit existing FORTRAN coded TH simulation source to include sensitivity calculations are described herein.