Abstract: Gas-cooled high temperature reactor asembly, including a safety container, a chamber disposed in the safety container, a reactor vessel disposed in the chamber for receiving a charge of spherical fuel elements at a given location therein, the reactor vessel being formed of blocks of at least one material from the group consisting of carbon and graphite, a steel shell surrounding the reactor vessel, a metallic base plate supporting the reactor vessel, the base plate having openings formed therein for passing cooling gas blown in the chamber into the given location for a fuel element charge, at least one downwardly extended pipeline having a connection to the base plate for discharging heated gases, the connection being detachable by axial motion of the reactor vessel, a removable cover disposed on top of the chamber, and means disposed on the reactor vessel for connecting the reactor vessel to hoisting apparatus.

Abstract: Pebble-bed nuclear reactor capable of being shut down by a fluidized mass of bodies containing neutron-absorbing material, the fluidized mass of bodies being received in a storage container disposed above the pebble bed during normal operation of the reactor, the storage container being formed with a closable discharge opening, including a piston rigidly connected to the storage container and disposed below the discharge opening thereof, the piston being guided in a cylinder stationary relative to the reactor and being open at the top thereof, the storage container being displaceable in vertical direction between upper and lower end positions thereof, the piston, in the upper end position of the storage container, closing off the cylinder at the upper edge located at the open top of the cylinder and, in the lower end position of the storage container, the fluidized mass of bodies discharged from the discharge opening of the storage container being formed on top of the piston into a discharge cone having a hei

Abstract: Mixing and distributing device for gases having high temperature includes a multiplicity of polygonal blocks stacked in a plurality of layers above and laterally adjacent one another, the blocks being formed with channels having respective axes disposed at an angle to one another and to a main gas in-flow direction, the channels of the respective blocks being connected with adjacent channels of the same or an adjacent block, the multiplicity of polygonal blocks defining a space wherein high temperature is producible.

Abstract: In a reactor vessel for pebble beds at high and varying temperatures having a side wall and a base formed of a multiplicity of stacked blocks of heat-resistant material and held together by an outer cylindrical or polygonal ring and supported on a foundation, the base and the side wall, respectively, being formed of a plurality of sectors having substantially vertical, radial parting lines therebetween, the sectors being supported with slight friction on the foundation and being braced against the outer ring, the sectors having boundary surfaces with a pebble bed, support surfaces on the foundation and abutment surfaces against the outer ring, the respective surfaces of the boundary surfaces, the support surfaces and the abutment surfaces having a convex mutual inclination whereby each of the sectors is held together in itself by external forces and is forced by its own weight and the weight of the pebble bed into a definite position.

Abstract: For gas-cooled pebble-bed reactors, an absorber element in the form of a hollow, helical spiral coil is proposed, which moves directly through the pebble bed essentially through rotary motion. This form not only facilitates the penetration into greater depths of the pebble bed, but also has a substantially greater absorber effect as compared to the known, essentially cylindrical absorber rods with the same absorber volume, so that the number of absorber elements can be reduced.

Abstract: A pebble-bed nuclear reactor of large power rating comprises a container having a funnel-shaped bottom forming a pebble run-out having a centrally positioned outlet. A bed of downwardly-flowing substantially spherical nuclear fuel pebbles is positioned in the container and forms a reactive nuclear core maintained by feeding unused pebbles to the bed's top surface while used or burned-out pebbles run out and discharge through the outlet. A substantially conical body with its apex pointing upwardly and its periphery spaced from the periphery of the container spreads the bottom of the bed outwardly to provide an annular flow down the funnel-shaped bottom forming the run-out, to the discharge outlet. This provides a largely constant downward velocity of the spheres throughout the diameter of the bed throughout a substantial portion of the down travel, so that all spheres reach about the same burned-out condition when they leave the core, after a single pass through the core area.