Patent Number: 040574644
Section: claims

1. A nuclear reactor installation comprising a reactor building forming a containment which is closed during reactor operation and internally defines an equipment zone containing radiating components and an operating zone which is accessible to workmen, and having a system for providing an atmospheric overpressure in the operating zone relative to the atmospheric pressure in the equipment zone; wherein the improvement comprises said system having means for removing a flow of atmosphere from said equipment zone, filter means for filtering said flow, and means for introducing a flow of the atmosphere filtered by said filter means to said operating zone under said overpressure. 2. The installation of claim 1 in which said filter means removes iodine from the flow of atmosphere removed from the equipment room. 3. The installation of claim 2 in which said building forms a room enclosed from said operating room and has means for removing a flow of atmosphere from the operating room and means for filtering the removed flow of atmosphere to remove rare gases therefrom, and means for introducing a flow of this removed and filtered atmosphere to said room. 4. The installation of claim 3 in which said means for removing atmosphere from the operating zone, removes a flow of about one-twentieth of the atmospheric flow introduced to said equipment room. 5. The installation of claim 4 in which a double-door connects said room with said operating zone. 6. The installation of claim 2 in which said system has means for drying the flow of atmosphere removed from said equipment room prior to its introduction to said operating zone. 7. The installation of claim 1 having controllable means for directly interconnecting said zones for atmospheric flow therebetween. 8. The installation of claim 1 in which said building forms at least one radiation dangerous room and said operating zone is connected to feed its overpressure atmosphere back to said equipment zone via said dangerous room. 9. The installation of claim 1 in which said reactor building is closed by a spherical steel containment shell and a secondary concrete shield having a cylindrical wall forming a closed annular space for containing auxiliary equipment around the containment shell, and has exhaust means for exhausting the atmosphere from said annular space to the atmosphere outside of the building, said exhaust means including filter means for filtering the exhausting atmosphere from said annular space. 10. The installation of claim 1 in which said building has means for purging all of its enclosed spaces with fresh atmosphere from outside of the building.