SENSITIVITIES OF SOME CHARACTERISTICS OF NUCLEAR EQUILIBRIUM STATE TOONE-GROUP CONSTANTS

In the nuclear equilibrium state, the nuclide densities and h-value (a neutron balance index) can be estimated from one-group nuclear consta nts. One-group cross sections usually contain some uncertainties origi nated from nuclear data errors, analysis errors and design uncertainti es. The method to obtain sensitivity coefficients of nuclide densities and h-value to one-group constants are derived by the use of perturba tion method, and some numerical results are obtained for both fast and thermal reactors. The numerical results show several notable characte ristics. It is appeared that many of these characteristics can be expl ained using only the main nuclide chain. The method developed in this paper, some derived characteristics and/or numerical results for typic al reactors may be useful for future studies based on the nuclear equi librium state.