Abstract: Reactor building structure comprising a ring building roof embedded in the cylindrical skirt of the confinement enclosure.The structure is constituted by a confinement enclosure comprising a cylindrical skirt and a dome, as well as by a ring building surrounding the confinement enclosure. The ring building comprises a cylindrical skirt and a roof, the confinement enclosure and the ring building being erected on a common general foundation raft or floor. The internal structures are positioned with the confinement enclosure. The roof of the ring building is toroidal or frustum-shaped, being embedded in the cylindrical skirt of the confinement enclosure. The internal structures are disengaged from the confinement enclosure.

Abstract: Reactor building comprising internal structures, whose stresses are independent of the deformations of the general floor and of the background effect due to the reference accident pressure, and process for producing the internal structures.This reactor building comprises a confinement enclosure (4), internal structures (14) constituted by a slab (22) peripherally locked against the frustum-shaped member (12) of confinement enclosure (4) and resting on the general floor (8) by a peripheral supporting ring (23), a compressible layer (32) being provided between the general floor (8) and slab (22).Application to the construction of the internal structures of a reactor building.