Arrangement for supporting U-bend tube sections in the high heat environment of steam generators using flat bars. The invention uses a combination of thicker and thinner flat bars to impart a serpentine path to the arc of the normally curvilinear U-tubes. The support system accommodates the dilation and contraction of coolant tubes and other elements caused by the extreme and varying conditions inside a steam generator, and which can cause gaps between coolant tubes and prior art tube support bars. Bars of alternating thickness provide alternating offsets to tensionally push and support each tube on multiple sides and in multiple locations, and this tension keeps the tubes in contact with at least some flat bars on multiple sides regardless of size and shape changes. Support arrangement includes a set of fan bars, each fan bar including thick and thin flat bars projecting up and out from a collector bar.

Arrangement for supporting U-bend tube sections in the high heat environment of steam generators using flat bars. The invention uses a combination of thicker and thinner flat bars to impart a serpentine path to the arc of the normally curvilinear U-tubes. The support system accommodates the dilation and contraction of coolant tubes and other elements caused by the extreme and varying conditions inside a steam generator, and which can cause gaps between coolant tubes and prior art tube support bars. Bars of alternating thickness provide alternating offsets to tensionally push and support each tube on multiple sides and in multiple locations, and this tension keeps the tubes in contact with at least some flat bars on multiple sides regardless of size and shape changes. Support arrangement includes a set of fan bars, each fan bar including thick and thin flat bars projecting up and out from a collector bar.

A closed loop heat convection cooling system for nuclear reactors. The cooling system is formed outside the containment structure of the nuclear reactor and the structure of the cooling system prevents gas that is not in the closed circuit to approach the reactor within neutron radiation distance. The cooling systems has cooling assemblies that are housed in protective structures, which shield the cooling assemblies for projectile impact. Air inlet and outlet apertures are formed in the protective structures to cause outside air to be drawn into the protective structures to cool the cooling assemblies.

A closed loop heat convection cooling system for nuclear reactors. The cooling system is formed outside the containment structure of the nuclear reactor and the structure of the cooling system prevents gas that is not in the closed circuit to approach the reactor within neutron radiation distance. The cooling systems has cooling assemblies that are housed in protective structures, which shield the cooling assemblies for projectile impact. Air inlet and outlet apertures are formed in the protective structures to cause outside air to be drawn into the protective structures to cool the cooling assemblies.

A system for removing thermal energy generated by radioactive materials is provided. The system comprises an air-cooled shell-and-tube heat exchanger, comprising a shell and plurality of heat exchange tubes arranged in a substantially vertical orientation within the shell, the heat exchange tubes comprising interior cavities that collectively form a tube-side fluid path, the shell forming a shell-side fluid path that extends from an air inlet of the shell to an air outlet of the shell, the air inlet at a lower elevation than the air outlet; a heat rejection closed-loop fluid circuit comprising the tube-side fluid path, a coolant fluid flowing through the heat rejection closed-loop fluid circuit, the heat rejection closed-loop fluid circuit thermally coupled to the radioactive materials; and the air-cooled shell-and-tube heat exchanger transferring thermal energy from the coolant fluid flowing through the tube-side fluid path to air flowing through the shell-side fluid path.

A system for removing thermal energy generated by radioactive materials is provided. The system comprises an air-cooled shell-and-tube heat exchanger, comprising a shell and plurality of heat exchange tubes arranged in a substantially vertical orientation within the shell, the heat exchange tubes comprising interior cavities that collectively form a tube-side fluid path, the shell forming a shell-side fluid path that extends from an air inlet of the shell to an air outlet of the shell, the air inlet at a lower elevation than the air outlet; a heat rejection closed-loop fluid circuit comprising the tube-side fluid path, a coolant fluid flowing through the heat rejection closed-loop fluid circuit, the heat rejection closed-loop fluid circuit thermally coupled to the radioactive materials; and the air-cooled shell-and-tube heat exchanger transferring thermal energy from the coolant fluid flowing through the tube-side fluid path to air flowing through the shell-side fluid path.

A closed loop heat convection cooling system for nuclear reactors. The cooling system is formed outside the containment structure of the nuclear reactor and the structure of the cooling system prevents gas that is not in the closed circuit to approach the reactor within neutron radiation distance. The cooling systems has cooling assemblies that are housed in protective structures, which shield the cooling assemblies for projectile impact. Air inlet and outlet apertures are formed in the protective structures to cause outside air to be drawn into the protective structures to cool the cooling assemblies.

A closed loop heat convection cooling system for nuclear reactors. The cooling system is formed outside the containment structure of the nuclear reactor and the structure of the cooling system prevents gas that is not in the closed circuit to approach the reactor within neutron radiation distance. The cooling systems has cooling assemblies that are housed in protective structures, which shield the cooling assemblies for projectile impact. Air inlet and outlet apertures are formed in the protective structures to cause outside air to be drawn into the protective structures to cool the cooling assemblies.

System for storing radioactive materials comprising: —a canister (4) containing radioactive waste; —a container (C), provided with a casing (1), a base (2) and a cover (3), and a passive helicoidal convection-based ventilation system provided with: lower air inlets (5); an area (6) of air circulation between the canister (4) and the inner surface of the container (C), and upper air outlets (7); the inlets (5) and outlets (7) have a decreasing variation of section in the direction of air circulation, are curved and facing an oblique direction with respect to the radial direction of the container, the air between said inlets (5) and outlets (7) describing an upward helicoidal path around the capsule or canister (4).

System for storing radioactive materials comprising: —a canister (4) containing radioactive waste; —a container (C), provided with a casing (1), a base (2) and a cover (3), and a passive helicoidal convection-based ventilation system provided with: lower air inlets (5); an area (6) of air circulation between the canister (4) and the inner surface of the container (C), and upper air outlets (7); the inlets (5) and outlets (7) have a decreasing variation of section in the direction of air circulation, are curved and facing an oblique direction with respect to the radial direction of the container, the air between said inlets (5) and outlets (7) describing an upward helicoidal path around the capsule or canister (4).