Abstract:
A composite moderator medium for nuclear reactor systems and a method of fabricating a composite moderator block formed of the composite moderator medium The composite moderator medium includes two or more moderators, such as a low moderating material and a high moderating material. The high moderating material has a higher neutron slowing down power compared to the low moderating material. The low moderating material includes a moderating matrix of silicon carbide or magnesium oxide. The high moderating material is dispersed within the moderating matrix and includes beryllium, boron, or a compound thereof. The high moderating material is encapsulated within the low moderating material such that the high moderating material is not exposed outside of the low moderating material. The method can include selecting a sintering aid and a weight percent of the sintering aid in a composite moderator mixture based on the low moderating material and spark plasma sintering.
Abstract:
La présente invention concerne une configuration de cœur de réacteur à neutrons rapides, refroidi par un métal liquide. Le cœur comporte un ensemble d'éléments combustibles comprenant un matériau fertile et/ou un matériau fissile, l'ensemble de tels éléments combustibles étant agencé selon une forme générale de cylindre. Au sens de l'invention, un premier ensemble d'éléments combustibles (Cl, C2, C3), disposé selon une couronne en périphérie du cylindre, comporte relativement plus de matériau fissile qu'un deuxième ensemble d'éléments combustibles (FERT), disposé au centre du cylindre. Un tel agencement permet avantageusement de réduire un effet de vidange du métal liquide et de là, d'améliorer la sécurité du réacteur.
Abstract:
A modular, nuclear waste conversion reactor that continuously produces usable energy while converting U-238 and/or other fertile waste materials to fissionable nuclides. The reactor has a highly uniform, self-controlled, core (2) with a decades-long life and does not require reactivity control mechanisms within the boundary of the active core during operation to retain adequate safety. The exemplary embodiment employs high-temperature helium coolant, a dual-segment (22) initial annular critical core, carbide fuel, a fission product gas collection system, ceramic cladding and structural internals to create a modular reactor design that economically produces energy over multiple generations of reactor cores with only minimum addition of fertile material from one generation to the next.
Abstract:
A nuclear reactor may comprise: fuel comprising or breeding plutonium-239; a neutron moderator, such as ZrHx, where x is about 1.6, YH 2, TiH 2 and/or ThH 2 , which behaves as an Einstein oscillator and as the temperature of the reactor increases the moderator increases the energy of thermal neutrons into the Pu-239 neutron absorption resonance; and a neutron absorbing element with strong neutron absorption around 0.3 eV added to one or more components of a reactor core of the nuclear reactor, wherein the neutron absorbing element is provided in an amount calculated to suppress, at any time during the life of the fuel, a reactivity gain with temperature due to the neutron moderator increasing the energy of thermal neutrons into the Pu-239 neutron absorption resonance.
Abstract:
Seed-blanket type nuclear reactor cores (10, 100) are employed to burn thorium fuel with conventional reactor fuels, including nonproliferative enriched uranium, and weapons or reactor grade plutonium. In a first embodiment, the core (10) is completely nonproliferative in that neither the reactor fuel, nor the generated waste material, can be used to manufacture nuclear weapons. In a second embodiment of the invention, the core (100) is employed to burn large amounts of weapons grade plutonium with the thorium, and provides a convenient mechanism by which stockpiled weapons grade plutonium can be destroyed and converted into electrical energy. The cores of both embodiments are comprises of a plurality of seed-blanket units (12, 102) which have centrally located seed regions (18, 104) that are surrounded by annular blanket regions (20, 106). The seed regions contain the uranium or plutonium fuel rods (22, 110), while the blanket regions contain thorium fuel rods (26, 118).
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.