SENSITIVITY THEORY FOR GENERAL SYSTEMS OF NONLINEAR EQUATIONS.

General sensitivity theory is presented for treating problems characterized by systems of nonlinear equations with nonlinear responses. Also presented is an alternative sensitivity formalism for systems of nonlinear matrix equations, such as those arising from the application of numerical methods to many practical problems. To demonstrate the usefulness and practical applications of both operator and matrix formalisms, a significantly nonlinear transient problem in fast reactor thermal hydraulics is considered. Following the derivation and comparative analysis of the adjoint equations and sensitivity expressions using both formalisms, an extensive sensitivity study for this problem is presented. Conclusions about the future applicability of the general theory are also discussed.