Continuous-energy perturbation calculations using Taylor series expansion in the MORET code

The MORET code, developed at IRSN (Institut de Radioprotection et de Surete nucleaire), is a simulation tool that solves the transport equation for neutrons using the Monte Carlo method. Recently have been implemented the perturbation procedure using first order Taylor series expansion in the continuous-energy calculation relying on the estimation of sensitivity coefficient to isotopic concentrations which have been recently implemented in the MORET code. Thus, the MORET code now offers the users the possibility to use either the correlated sampling or taylor series methods to estimate perturbations. The present paper describes the continuous-energy perturbation method based on the Taylor series expansion which have been implemented in the last release of the code. In addition, some considerations about the implementation and the verification are presented. The verification has been performed using several ICSBEP and OECD/NEA benchmarks and some configurations of the french proprietary experimental program MIRTE. (authors)