Pressure vessel assembly for high-temperature nuclear reactor

In a pressure-vessel assembly for a nuclear-reactor installation wherein a central pressure vessel of cast material and of generally cylindrical configuration is adapted to receive a high-temperature nuclear reactor, and a plurality of component vessels of cast material surround the central vessel and communicate by respective gas passages therewith, the component vessels receiving heat exchangers for at least a primary coolant for the nuclear reactor, the improvement wherein:

• the central vessel communicates with each of the component vessels via a respective one of said passages with the passages lying in a common horizontal plane and extending radially of the central vessel;
• said central vessel is provided with a multiplicity of generally vertical planar surfaces in said horizontal plane, respective ones of said surfaces lying at right angles to the respective passages;
• said component vessels are provided with planar surfaces in the region of said passages with one planar surface lying flat against a corresponding surface of said central vessel perpendicular to the passage communicating between the respective component vessel and the central vessel;
• respective support blocks of a height substantially equal to that of said planar surfaces are received between pairs of said component vessels and have planar surfaces lying against the planar surfaces of said central vessel between said component vessels and of said component vessels;
• and
• at least one inward prestressing member extends peripherally around the assembly and bears inwardly upon said support blocks and said component vessels, said support blocks, said central vessel and said component vessels forming a compound-disk structure in the region in which said component vessels and support blocks are engaged by said member.