Effect of microconstants uncertainty on transplutonium actinides burnup in molten salt reactors

An evaluation method and results for the error due to microconstants uncertainties in the calculation of neptunium and transplutonium actinide burnup in a molten-salt reactor are presented. The method developed treats the characteristics of a reactor in an equilibrium state and assumes that Np, Am, Cm, and other transplutonium elements as well as material for maintaining criticality are fed continually into the reactor. The perturbation of the equilibrium characteristics of the reactor is described using a linear approximation taking account of the limitations on the prescribed power, k_eff of the reactor, and the actinide content in the fuel salt. The error in the burnup rate is calculated for a homogeneous reactor with NaF-ZrF₄ salt. Different sources are used to determine the errors in the microconstants. The resulting error obtained for Np, Am, Cm, and other transplutonium element burnup ranges from 12 to 51% depending on the reactor power. __________ Translated from Atomnaya énergiya, Vol. 102, No. 5, pp. 270–276, May, 2007.