The invention concerns a nuclear reactor comprising a vessel closed at the top by a radially external fixed closing structure and by a radially internal mobile closing structure. The vessel contains a core immersed in a primary cooling fluid and comprising fuel elements, control rods, shutdown rods, and a hydraulic separation structure delimiting a hot manifold and a cold manifold in which the primary fluid circulates. The control rods and the shutdown rods are inserted in respective penetrations of the fixed closing structure and are therefore located radially external to the mobile closing structure and external to an upper portion of the separation structure containing respective heads of the fuel elements.
G21C 1/03 - Fast fission reactors, i.e. reactors not using a moderator cooled by a coolant not essentially pressurised, e.g. pool-type reactors
G21C 1/14 - Heterogeneous reactors, i.e. in which fuel and moderator are separated moderator being substantially not pressurised, e.g. swimming-pool reactor
The present invention concerns a nuclear reactor, preferably a pool-type nuclear reactor cooled by liquid metal or molten salts, having a core formed of a bundle of fuel elements and immersed in a primary fluid for cooling the core; the fuel elements are provided with expanders acting in a direction perpendicular to the axes of the fuel elements and having low thermal expansion elements which engage alternatively with high thermal expansion elements to amplify the radial expansion of respective end elements which, when a predetermined temperature is exceeded, engage with each other and space the fuel elements from one another and in particular their active part to introduce negative reactivity into the core.
One or more embodiments of the present invention relate to a pump/heat exchanger assembly of a nuclear reactor, in particular a liquid metal cooled nuclear reactor, the pump being characterized in that the shaft for driving the impeller is inserted in an shell inside the heat exchanger and has a smaller cross section at the bottom part of the tube bundle of the heat exchanger and a cross section that gradually increases up to a widest cross section at the top part of the tube bundle of the heat exchanger. The resulting axial profile of the impeller's shaft is, at the same time, designed to uniformly distribute the flow of the primary fluid inside the tube bundle of the heat exchanger and to provide high mechanical inertia to the pump.
G21C 15/247 - Promoting flow of the coolant for liquids for liquid metals
F04D 7/06 - Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts of centrifugal type the fluids being hot or corrosive, e.g. liquid metal
F04D 7/08 - Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts of centrifugal type the fluids being radioactive
F22B 1/06 - Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being molten; Use of molten metal, e.g. zinc, as heat transfer medium
4.
Nuclear reactor, in particular liquid-metal-cooled compact nuclear reactor
The present invention relates to a nuclear reactor (1), in particular a liquid-metal-cooled reactor, provided with a separation structure (5) between hot header (6) and cold header (7), narrower in the upper portion (16) for containment of the headers of the fuel assemblies and wider in the lower element (14) at the active part (4) of the core, with a variously shaped connecting element (15) between the lower element (14) and the upper element (16), and with heat exchangers (11) positioned between the upper portion (16) of said separation structure (5) and the reactor vessel (2), which engage on the connecting element (15) via vertical ducts (20) for being fed with hot primary fluid leaving the core (4).
G21C 1/03 - Fast fission reactors, i.e. reactors not using a moderator cooled by a coolant not essentially pressurised, e.g. pool-type reactors
G21C 15/14 - Arrangement or disposition of passages in which heat is transferred to the coolant, e.g. for coolant circulation through the supports of the fuel elements from ducts comprising auxiliary apparatus, e.g. pumps, cameras
G21C 1/32 - Integral reactors, i.e. reactors wherein parts functionally associated with the reactor but not essential to the reaction, e.g. heat exchangers, are disposed inside the enclosure with the core
G21C 5/02 - Moderator or core structure; Selection of materials for use as moderator - Details
G21C 15/06 - Arrangement or disposition of passages in which heat is transferred to the coolant, e.g. for coolant circulation through the supports of the fuel elements from fissile or breeder material in fuel elements
G21C 15/22 - Structural association of coolant tubes with headers or other pipes, e.g. in pressure tube reactors
A nuclear reactor (1) comprises a vessel (2) closed at the top by a fixed closing structure (3) and a mobile closing structure (4) and containing a core (5) and a hydraulic separation structure (6) delimiting a hot manifold (7) and a cold manifold (8) in which a primary fluid (F) for cooling the core (5) circulates, with a first free surface (H1) in the hot manifold (7) which, during normal operation of the reactor (1), is different from a second free surface (H2) in the cold manifold (8); the core (5) comprises shutdown rods (18) which are operated by at least one float (26) which, via a down-up movement, positions respective neutron absorbers (23) in the vicinity of the active part (12) of the core when the level (H1) of the primary fluid (F) increases due to slowing down of the circulation pumps (9).
G21C 7/08 - Control of nuclear reaction by application of neutron-absorbing material, i.e. material with absorption cross-section very much in excess of reflection cross-section by displacement of solid control elements, e.g. control rods
G21C 9/027 - Means for effecting very rapid reduction of the reactivity factor under fault conditions, e.g. reactor fuse by fast movement of a solid, e.g. pebbles
G21C 1/03 - Fast fission reactors, i.e. reactors not using a moderator cooled by a coolant not essentially pressurised, e.g. pool-type reactors
G21C 1/14 - Heterogeneous reactors, i.e. in which fuel and moderator are separated moderator being substantially not pressurised, e.g. swimming-pool reactor
6.
NUCLEAR REACTOR, WITH CONTROL AND SHUTDOWN RODS EXTERNAL TO THE CORE AND TO ITS SUPPORTING STRUCTURES
The invention concerns a nuclear reactor (1), comprising a vessel (2) closed at the top by a radially external fixed closing structure (3) and by a radially internal mobile closing structure (4) and containing a core (5), immersed in a primary cooling fluid (F) and comprising fuel elements (11) and control and shutdown rods (18), and a hydraulic separation structure (6) delimiting a hot manifold (7) and a cold manifold (8) in which the primary fluid (F) circulates; the control rods (18a) and shutdown rods (18b, 18c) are inserted in respective penetrations (19a, 19b, 19c) of the fixed closing structure (3) and are therefore located radially external to the mobile closing structure (4) and external to an upper portion (17) of the separation structure (6) containing respective heads (15) of the fuel elements (12).
G21C 9/027 - Means for effecting very rapid reduction of the reactivity factor under fault conditions, e.g. reactor fuse by fast movement of a solid, e.g. pebbles
G21C 13/02 - Pressure vessels; Containment vessels; Containment in general - Details
G21C 1/03 - Fast fission reactors, i.e. reactors not using a moderator cooled by a coolant not essentially pressurised, e.g. pool-type reactors
G21C 1/14 - Heterogeneous reactors, i.e. in which fuel and moderator are separated moderator being substantially not pressurised, e.g. swimming-pool reactor
7.
NUCLEAR REACTOR, WITH CONTROL AND SHUTDOWN RODS EXTERNAL TO THE CORE AND TO ITS SUPPORTING STRUCTURES
The invention concerns a nuclear reactor (1), comprising a vessel (2) closed at the top by a radially external fixed closing structure (3) and by a radially internal mobile closing structure (4) and containing a core (5), immersed in a primary cooling fluid (F) and comprising fuel elements (11) and control and shutdown rods (18), and a hydraulic separation structure (6) delimiting a hot manifold (7) and a cold manifold (8) in which the primary fluid (F) circulates; the control rods (18a) and shutdown rods (18b, 18c) are inserted in respective penetrations (19a, 19b, 19c) of the fixed closing structure (3) and are therefore located radially external to the mobile closing structure (4) and external to an upper portion (17) of the separation structure (6) containing respective heads (15) of the fuel elements (12).
G21C 9/027 - Means for effecting very rapid reduction of the reactivity factor under fault conditions, e.g. reactor fuse by fast movement of a solid, e.g. pebbles
G21C 13/02 - Pressure vessels; Containment vessels; Containment in general - Details
G21C 1/03 - Fast fission reactors, i.e. reactors not using a moderator cooled by a coolant not essentially pressurised, e.g. pool-type reactors
G21C 1/14 - Heterogeneous reactors, i.e. in which fuel and moderator are separated moderator being substantially not pressurised, e.g. swimming-pool reactor
8.
NUCLEAR REACTOR WITH FUEL ELEMENTS EQUIPPED WITH A COOLING DUCT
A nuclear reactor (1) comprising a vessel (2) that houses a core (4), comprising a bundle of fuel elements (12), and immersed in a primary cooling fluid (F) of the core; the fuel elements (12) extend along respective longitudinal and parallel axes (A) and wherein the head (16) of said fuel elements (12) is hydraulically connected to a tubular structure (26) that extends centrally for the entire active part (13) of the fuel elements (12); the tubular structure (26) is hydraulically closed at the bottom end (28) and is provided with a plurality of small holes (27) along the entire length corresponding to the active part (13) of the fuel elements (12).
The present invention concerns a nuclear reactor (1), preferably a pool-type nuclear reactor cooled by liquid metal or molten salts, having a core (4) formed of a bundle of fuel elements (12) and immersed in a primary fluid (F) for cooling the core; the fuel elements (12) are provided with expanders (50) acting in a direction perpendicular to the axes (A) of the fuel elements (12) and having low thermal expansion elements (51) which engage alternatively with high thermal expansion elements (52) to amplify the radial expansion of respective end elements (53) which, when a predetermined temperature is exceeded, engage with each other and space the fuel elements (12) from one another and in particular their active part (13) to introduce negative reactivity into the core.
The present invention relates to a pump/heat exchanger assembly (5) of a nuclear reactor (1), in particular a liquid metal cooled nuclear reactor, the pump (6) being characterized in that the shaft (14) for driving the impeller (15) is inserted in an shell (9) inside the heat exchanger (8) and has a smaller cross section at the bottom part of the tube bundle of the heat exchanger and a cross section that gradually increases up to a widest cross section at the top part of the tube bundle of the heat exchanger (8). The resulting axial profile of the impeller's shaft is, at the same time, designed to uniformly distribute the flow of the primary fluid inside the tube bundle (20) of the heat exchanger (8) and to provide high mechanical inertia to the pump (6).
G21C 15/247 - Promoting flow of the coolant for liquids for liquid metals
G21C 15/243 - Promoting flow of the coolant for liquids
F04D 7/06 - Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts of centrifugal type the fluids being hot or corrosive, e.g. liquid metal
F22B 1/06 - Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being molten; Use of molten metal, e.g. zinc, as heat transfer medium
G21C 1/03 - Fast fission reactors, i.e. reactors not using a moderator cooled by a coolant not essentially pressurised, e.g. pool-type reactors
11.
Passive system for evacuating the residual heat from a nuclear reactor
AGENZIA NAZIONALE PER LE NUOVE TECNOLOGIE, L'ENERGIA E LO SVILUPPO ECONOMICO SOSTENIBLE (ENEA) (Italy)
HYDROMINE NUCLEAR ENERGY S.A.R.L. (Luxembourg)
Inventor
Cinotti, Luciano
Agostini, Pietro
Tarantino, Mariano
Abstract
A system for evacuating the residual heat from a nuclear reactor comprises: a first heat exchanger, which transfers heat from a primary fluid of the reactor to a secondary fluid; a second heat exchanger, where the secondary fluid is cooled by an auxiliary fluid which crosses a cooling duct; and a control portion, subject to thermal expansion by effect of the heating, induced by an increase in the temperature of the primary fluid beyond a preset threshold, of the secondary fluid in the control portion; the control portion being connected to a mechanical actuator device moved by the thermal expansion of the control portion to open the cooling duct and allow the passage of auxiliary fluid into the cooling duct and through the second heat exchanger.
The present invention relates to a nuclear reactor (1), in particular a liquid-metal-cooled reactor, provided with a separation structure (5) between hot header (6) and cold header (7), narrower in the upper portion (16) for containment of the headers of the fuel assemblies and wider in the lower element (14) at the active part (4) of the core, with a variously shaped connecting element (15) between the lower element (14) and the upper element (16), and with heat exchangers (11) positioned between the upper portion (16) of said separation structure (5) and the reactor vessel (2), which engage on the connecting element (15) via vertical ducts (20) for being fed with hot primary fluid leaving the core (4).
G21C 1/32 - Integral reactors, i.e. reactors wherein parts functionally associated with the reactor but not essential to the reaction, e.g. heat exchangers, are disposed inside the enclosure with the core
AGENZIA NAZIONALE PER LE NUOVE TECNOLOGIE, L'ENERGIA E LO SVILUPPO ECONOMICO SOSTENIBILE (ENEA) (Italy)
HYDROMINE NUCLEAR ENERGY S.A.R.L. (Luxembourg)
Inventor
Agostini, Pietro
Tarantino, Mariano
Cinotti, Luciano
Abstract
A system (10) for evacuating the residual heat from a nuclear reactor (1) comprises: a first heat exchanger (11), which transfers heat from a primary fluid (5) of the reactor (1) to a secondary fluid (15); a second heat exchanger (12), where the secondary fluid (15) is cooled by an auxiliary fluid (16) which crosses a cooling duct (17); and a control portion (40), subject to thermal expansion by effect of the heating, induced by an increase in the temperature of the primary fluid (5) beyond a preset threshold, of the secondary fluid (15) in the control portion (40); the control portion (40) being connected to a mechanical actuator device (32) moved by the thermal expansion of the control portion (40) to open the cooling duct (17) and allow the passage of auxiliary fluid (16) into the cooling duct (17) and through the second heat exchanger (12).
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