[en] This report presents a synthetic status of the researches conducted within the Nuclear Energy Division (CEA/DEN) in the field of radionuclides migration in three specific areas which have been chosen for their representativeness and potential impact: the migration of RN in PWR reactors, the migration of RN from a deep geological repository and the migration processes in the surface environments. In addition, some status is given about more generic research which is conducted in the field of RN speciation in the aqueous phase and at the interfaces and regarding chemistry / transport couplings. Additional information about the human and technical means involved in these fields of research in CEA/DEN is finally given in the Appendix. (authors)