Patent Number: 048511862
Section: claims

1. A core of a nuclear reactor comprising detachable vertical assemblies having a lower part, a bolster including hollow pillars each having a vertical axis and receiving said lower part of said assemblies, first openings in said pillars for the passage of a coolant fluid for the reactor, second openings in said lower parts of said assemblies in alignment with said first openings in said pillars, each pillar including at least one means for orienting the respective assembly about said axis of said pillar and each assembly comprising (a) a vertical body having an upper part in the form of an open tubular case having a lateral wall and openings extending through said lateral wall of said tubular case and so located that the body of the assembly is placed in a predetermined position as concerns its orientation about its vertical axis below a handling device having claws engaged in said openings; and  (b) a lower part having at least one orientation means adapted to cooperate with the corresponding orientation means of said pillar, when introducing said lower part of the assembly in the said pillar in a predetermined orientation by means of said handling device. 2. A core of a nuclear reactor according to claim 1, wherein the orientation means of said pillar comprises a prismatic cavity provided inside said pillar and the corresponding orientation means of said lower part of said assembly comprises a male prismatic surface of corresponding shape provided on said lower part of said assembly and being coaxial with said assembly. 3. A core of a nuclear reactor according to claim 2, wherein said prismatic surfaces have a hexagonal cross-sectional shape. 4. A core of a nuclear reactor according to claim 3, wherein the assemblies of the core comprise an annular member having an inner part connected to said tubular case of said body of said assembly located below said seizing means, and bars of a material absorbing neutrons constituting an upper neutronic protection carried by said annular member of the assembly. 5. A core of a nuclear reactor according to claim 1, wherein said assemblies of the core comprise a body of prismatic shape whose cross section is hexagonal.