EXPONENTIAL-TIME DIFFERENCING METHOD FOR SOLVING REACTOR POINT KINETICS EQUATIONS WITH TEMPERATURE AND POWER FEEDBACK AND ITS VALIDATION BY ANALYSINGTHERMAL REACTOR BENCHMARKS

Exponential Time Differencing method with Taylor Series Expansion (ETD-TS) is used for solving nonlinear systems of point kinetics equations (PKEs). Integral forms of PKE are expanded using Taylor Series Expansion method. Time step value and Taylor series expansion order (n) is chosen to minimize the truncation error.PKEs are highly stiff and nonlinear in nature in presence of thermal feedback. So, advanced method (ETD-TS) is used in the present work to estimate the power transients. Thermal Reactors benchmark with stepandcompensated ramp reactivity insertions are considered for estimation of power transients with feedback. Comparison of results with other accurate numerical methods likeCATS (Convergence Accelerated Taylor Series), SCS (Shifted Chebyshev Series), ITS2 (Integral Taylor Series)etc confirms the validity and accuracy of this method.Time step of 10-2 – 10-4sec is considered for estimationof power and reactivity transients.