[en] Under the auspices of Electricite de France, a feasibility study was performed concerning the dismantling of four PWR units and the on site entombment of the active components into a reactor containment building. An evaluation of activity and radwaste volume has been done. Regarding the relatively youthness of FRAMATOME PWR's in operation no decommissioning operation is scheduled before 1992. However in the past, FRAMATOME has gained practical experience related to partial dismantling of active components of nuclear reactors. The 1st reported experience is related to the thermal shield removal of the 1st PWR in operation in France, and the second example is related to the replacement of centering pins of control rod guide tube of some 900 MWe PWR's. To facilitate decommissioning, and to reduce the activation and contamination, a strict control of materials submitted to neutron flux is performed and, some practical measures have been taken at the design stage and during operation for minimizing the residual contamination of surfaces. To facilitate future dismantling operations, one takes into account, the possible replacement of large components at the design stage, several features of the plant lay out have been defined, and the documentation of the plant has to be correctly updated