[en] French Industrial Companies: EDF, AREVA (COGEMA and FRAMATOME-ANP), associated with ANDRA, the organization in charge of the waste management in France, and Public Research Institute CEA and IRSN, involved in the nuclear waste management, have developed in collaboration a methodology intended to assess the environmental and health impact of the nuclear fuel cycle. This methodology, based on fuel cycle simulation, Life Cycle Analysis, and Impact Studies of each fuel cycle facilities, has been applied to a set of nuclear scenarios covering a very contrasted range of waste management options, in order to characterize the effect of High Level Waste transmutation, and to estimate to what extent it could contribute to reduce their overall impact on health and environment. The main conclusion we could draw from this study is that it is not possible to discriminate, as far as health and environmental impacts are concerned, nuclear scenarios implementing very different levels of HLW transmutation, representative of the whole range of available options. The main limitation of this work is due to the hypothesis of normal behavior of all fuel cycle facilities: main future improvement of the methodology would be to take the accidental risk into account. (author)