[en] As any nuclear base installation evolves during its exploitation, some premises or buildings may change of use or be destroyed. In the first case, a complete cleaning up might be necessary to get rid of radioactive products. In order to deal with this issue, after a brief recall of the regulatory context and references, and a recall of the general doctrine of waste management in nuclear base installations in France, this guide project presents the principles for a complete cleaning up of structures belonging to an area containing nuclear wastes. It describes the modalities of definition of three different and successive defence lines. It defines the requirements in performing cleaning-up operations, the requirements in terms of quality insurance, and the different administrative procedures (before, during and after cleaning-up works). Some particular cases are addressed