OPTIMAL THORIUM-FUELED CANDU NUCLEAR REACTOR FUEL MANAGEMENT.

摘要

The optimization problem of in-core fuel management of a thorium-fueled CANDU nuclear reactor was investigated in terms of minimizing the total refueling rate at equilibrium refueling, while respecting criticality and power peaking constraints. The reactor model, with continuous refueling assumed, consisted of a one-dimension representation of a reflected core divided into several number of burnup zones, for which the average discharge fluences were considered as the decision variables. The coefficients of the two energy group diffusion equations were computed with the A.E.C.L. cell depletion code LATREP. Because of the presence of protactinium-233 in the fuel, the diffusion equations are non-linear, and a suitable computer code called CALYPSO had to be written to solve them by using a finite difference method.; The optimization problem itself was solved by the computer code ASTERIX, written as to use a steepest descent technique such that the number of diffusion calculations needed to converge are minimized. Simulations were performed on a CANDU 600 MW reactor model for cases where the constraint on the power peaking was active and inactive, and for reactor models divided into one, two and four burnup zones. Results indicated feed rate savings up to 14% for power peaking constrained problems.