Abstract:
A locking mechanism (95, 125, 130) for a nuclear fuel assembly (2) having seed and blanket (6) subassemblies is configured to selectively lock the seed subassembly within the blanket subassembly, preventing separation thereof. The locking mechanism contains one or more detents (95) on one of the seed subassembly or the blanket subassembly, that are configured to engage with a surface feature on the other of the seed subassembly or the blanket subassembly. The locking mechanism contains a locking member movable between two positions. In a first position, the locking member (100) is configured to prevent the one or more detents from disengaging from the surface feature (125, 130), thereby holding the blanket subassembly and the seed subassembly together. In a second position, however, the detents are able to move into a non- locking position, such that the one or more detents may disengage from the surface feature as the seed subassembly is separated from the blanket subassembly.
Abstract:
The present invention relates to a configuration of a liquid-metal-cooled fast-neutron reactor core. The core comprises an assembly of fuel elements comprising a fertile material and/or a fissile material, the assembly of such fuel elements being arranged in the general form of a cylinder. In the context of the invention, a first assembly of fuel elements (C1, C2, C3), arranged in a ring around the periphery of the cylinder, comprises relatively more fissile material than a second assembly of fuel elements (FERT), which is placed at the centre of the cylinder. Such an arrangement advantageously enables a liquid metal draining effect to be reduced and thereby improves the safety of the reactor.
Abstract:
Coeur de réacteur à neutrons rapides, refroidi par un métal liquide,à faible effet de vidange. Il comprend de haut en bas une zone neutrophage supérieure (8), une zone de plénum de métal liquide(10),une zone fissile supérieure(12), une zone fertile intermédiaire(14),une zone fissile inférieure(16);le plan médian horizontal(P1) de la zone fertile intermédiaire, de hauteur HFE*, est situé au dessous du plan médian horizontal (P2) de l'ensemble formé par les zones fissiles inférieure et supérieure et la zone fertile intermédiaire;et le rapport de HFE* à la hauteur de cet ensemble va de 0,25 à 0,40.
Abstract:
A nuclear reactor of the seed-blanket type having an active core (2) comprising seed regions (14) of fissile material and blanket regions (12 and 16) of fertile material capable of being converted into fissile material by neutron capture, the seed (14) and blanket regions (12, 16) being such as to produce a net reverse flow of neutron current as compared to conventional seed-blanket reactors, i.e. in the present reactor, the net fast neutron flow is from the blanket regions (12, 16) to the seed region (14) and the net thermal and epithermal neutron flow is from the seed region (14) to the blanket regions (12, 16). Such a reactor lends itself to the use of nonproliferative fuel, provides normal overall power densities, and requires low initial amounts of mined uranium.
Abstract:
An example of a system for producing and collecting one or more radioisotopes includes one or more fractional distillation columns that can receive a mixture and produce one or more radioisotopes using the mixture by fractional distillation. In various embodiments, a molten-salt nuclear reactor produces the mixture including one or more fission products. In various embodiments, the mixture includes helium gas carrying the one or more fission products, and the one or more radioisotopes include tritium.
Abstract:
A traveling wave nuclear fission reactor, fuel assembly, and a method of controlling burnup therein. In a traveling wave nuclear fission reactor, a nuclear fission reactor fuel assembly comprises a plurality of nuclear fission fuel rods that are exposed to a deflagration wave burnfront that, in turn, travels through the fuel rods. The excess reactivity is controlled by a plurality of movable neutron absorber structures that are selectively inserted into and withdrawn from the fuel assembly in order to control the excess reactivity and thus the location, speed and shape of the burnfront. Controlling location, speed and shape of the burnfront manages neutron fluence seen by fuel assembly structural materials in order to reduce risk of temperature and irradiation damage to the structural materials.
Abstract:
The present invention provides a modular nuclear reactor system comprising a reactor pressure vessel having a lower section having a first wall and a second wall and an upper section having a first wall and a second wall. The reactor includes a chimney with an attached heat exchanger. First and second passageways create a circulation loop wherein heated heat transfer fluid circulates up from the reactor core, through the chimney, through an upper plenum and downwardly past the heat exchanger, into a lower plenum and back into the core.
Abstract:
A liquid fluoride salt cooled, high temperature reactor having a reactor vessel with a pebble-bed reactor core. The reactor core comprises a pebble injection inlet located at a bottom end of the reactor core and a pebble defueling outlet located at a top end of the reactor core, an inner reflector, outer reflector, and an annular pebble- bed region disposed in between the inner reflector and outer reflector. The annular pebble-bed region comprises an annular channel configured for receiving pebble fuel at the pebble injection inlet, the pebble fuel comprising a combination of seed and blanket pebbles having a density lower than the coolant such that the pebbles have positive buoyancy and migrate upward in said annular pebble-bed region toward the defueling outlet. The annular pebble-bed region comprises alternating radial layers of seed pebbles and blanket pebbles.
Abstract:
A traveling wave nuclear fission reactor, fuel assembly, and a method of controlling burnup therein. In a traveling wave nuclear fission reactor, a nuclear fission reactor fuel assembly comprises a plurality of nuclear fission fuel rods that are exposed to a deflagration wave burnfront that, in turn, travels through the fuel rods. The excess reactivity is controlled by a plurality of movable neutron absorber structures that are selectively inserted into and withdrawn from the fuel assembly in order to control the excess reactivity and thus the location, speed and shape of the burnfront. Controlling location, speed and shape of the burnfront manages neutron fluence seen by fuel assembly structural materials in order to reduce risk of temperature and irradiation damage to the structural materials.