Development of a sensitivity and uncertainty analysis code for high temperature gas-cooled reactor physics based on the generalized perturbation theory

A computer code, MUSAD was developed for the uncertainty and sensitivity analysis on the DeCART neutron transport calculations for a high temperature gas-cooled reactor. MUSAD is based on a deterministic method in which the sensitivity coefficients of the multiplication factor and the microscopic cross sections are derived using the generalized perturbation theory. Then, the uncertainties of the reactor physics responses are calculated by the product of the covariance matrix and the sensitivity coefficients. MUSAD has been verified against the uncertainty analyses on several benchmark problems including the GODIVA benchmark problem, the PMR-200 pin-cell, and the MHTGR-350 core benchmark problems. A good agreement in comparison with the reference codes, TSUNAMI and McCARD shows the applicability of MUSAD to the uncertainty and sensitivity analyses on the HTGR neutron transport calculations.