Application of GRS method to evaluation of uncertainties of calculation parameters of perspective sodium-cooled fast reactor

摘要

Evaluation of calculation errors due to uncertainties of neutron data and technological parameters (geometrical and material data) has become one of the important problems of reactor physics. The well-known approach to solve this problem is based on the use of sensitivity coefficients (e.g. Ref. [1]) of reactor calculation parameters of interest to the input data (neutron cross sections, geometrical and material data). The main advantage of this approach is that small computational times are necessary. On the other hand, there are certain drawbacks of the approach. Sensitivities are usually calculated by the first-order perturbation theory, so the linear approximation is applied. Furthermore, there should be used different types of the perturbation theory for different types of calculation parameters. The most commonly used type of the perturbation theory allows one to compute sensitivities of Keff. Other modifications of the theory are more difficult to implement and use in 3D calculations. It is particularly difficult to calculate sensitivities of spatially distributed calculation parameters like power density.