Patent Number: 047434244
Section: summary

BACKGROUND OF THE INVENTION Field of the Invention The invention concerns a nuclear reactor installation comprising a cavity which is lined with a liner and arranged in a prestressed concrete pressure vessel. A high temperature reactor is provided on a circular base plate in the cavity. A plurality of core rods may be inserted into and retracted from an internal space containing spherical fuel elements by means of rod drives; and a plurality of reflector rods may be inserted into and retracted from a side reflector of said reactor by means of rod drives. The spherical fuel elements may be introduced by means of fuel element feeder-tubes and removed by at least one vertical, cooled outlet tube disposed on a base reflector. The nuclear reactor installation also has an annular cylindrical interstitial space formed between a thermal side shield and the liner. The thermal side shield surrounds a side reflector which forms a reactor core. The thermal side shield supports said reflector with radial supports. First heat exchangers, preferably steam generators, are arranged uprightly, aligned with an axial first passage through the roof of the pressure vessel. Said first heat exchangers are also interconnected with first blowers of a gas circulation loop through the nuclear reactor. Nuclear reactor installations of this type must satisfy particularly high safety requirements. This leads, in the case of known installations, particularly those with high capacity, to very expensive and cost intensive structures. Such added expense holds true for both the prestressed concrete pressure vessel and the development and arrangement of the individual structural elements of the nuclear reactor. SUMMARY OF THE INVENTION It is therefore an object of the invention to provide a nuclear reactor of the aforementioned type, particularly one with a capacity of approx. 300 MWe to 600 MWe; one which is suitable both for generating steam and supplying process heat; and one which has a simplified construction or individual structural elements, respectively, which are simply designed. It is also an object of the present invention to provide a nuclear reactor which allows radial expansions in a simple manner. It is a further object of the present invention to provide a nuclear reactor with a uniform capacity distribution of the spherical fuel elements so that hot strands are avoided. It is an object of the present invention to provide a nuclear reactor with simplified rod drive mechanisms and corresponding control means. It is an object of the present invention to provide a nuclear reactor which ensures a uniform passage rate of the fuel elements through the reactor core so as to increase efficiency. It is also an object of the present invention to provide a nuclear reactor in which radiation induced stresses in the reflector rods are reduced and limited. All of these objects should be met by the nuclear reactor according to the invention without comprising the reactors satisfaction of safety requirements. The above objects of the invention are attained with a nuclear reactor plant of the aforementioned type wherein: the bottom plate is composed of segments which are centered around a central reference point, and which are supported by means of radially displaceable double supports on the bottom of the pressure vessel; core rods are equipped with rod drives by means of which the core rods may be inserted, in a concerted manner, to only a part of the layer height of the spherical fuel elements, i.e., all the rods move simultaneously and to the same height; the reflector rods are equipped with electric motor rod drives; several uniformly distributed fuel element outlet tubes are provided in the bottom reflector for the discharge of fuel elements which pass through the nuclear reactor; first blowers are arranged in first passages through the roof of the pressure vessel, and disposed on slides guided in magnetic bearings; at least one upright heat exchanger is provided in the interstital space for removing the decay heat; a second passage, with which said heat exchanger is aligned, passes lengthwise through the bottom of the pressure vessel; a corresponding second blower is provided in said second passage, also dispositioned on slides with magnetic bearings; radial supports, particularly in the case of nuclear reactors with a capacity in excess of 400 MVe, are designed to be elastic and to prevent relative movements between the side reflector and the thermal side shield and are provided in at least the upper third of the height of the side reflector. Further objects, features, and advantages of the present invention will become apparent from the detailed description of preferred embodiments which follows, when considered together with the attached figures of drawings.