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AssigneeCommissariat a l'Energie Atomique
InventorsPatrick Aujollet, Jacques Porta, Stéfano Baldi
Estimating the term…
A single piece fuel element and fast spectrum boiling water reactor using such a single piece fuel element. The single piece fuel element is formed from coated fissile particles embedded in a matrix made from a material such as SiC that is inert to all fissile and fertile heavy nuclei and to the coolant fluid circulating in and around this element. Furthermore, the fuel element includes parallel plates delimiting spaces between them. A ratio between the thickness of the plates and the width of the spaces is set so that the fuel element can be put in fast spectrum or thermal spectrum at will. An application of the single piece fuel element to a fast spectrum boiling water nuclear reactor operating with natural circulation in which the above mentioned ratio is approximately equal to 1 enables a high consumption of plutonium.
A fuel element for a nuclear reactor, formed from coated fissile particles embedded in a matrix, comprising:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
Ceramic fuel: ceramic dispersion fuel, e.g. cermet
Moderator being highly pressurised, e.g. boiling water reactor, integral super-heat reactor, pressurised water reactor: boiling water reactors
Assemblies of a number of fuel elements in the form of a rigid unit: assemblies of plate-shaped fuel elements or coaxial tubes
Ceramic fuel: coated fuel particles
Term ended 10 Jan 2022 (estimated)
The invention relates mainly to a single piece or solid fuel element designed for use in the core of a nuclear reactor in contact with any coolant fluid such as water or a gas, to define a fast or thermal spectrum simply by adapting its dimensions.
The invention also relates to a fast spectrum boiling water nuclear reactor using fuel elements of this type. In particular, this type of reactor may be used to consume plutonium produced in existing nuclear pressurized water reactors used for the generation of electricity.
Nuclear reactors designed for the production of electrical energy commonly use square or hexagonal nuclear fuel assemblies placed side by side to form the reactor core.
We will now describe different embodiments of the invention as non-limitative examples with reference to the attached drawings in which:
FIG. 1 is a top view that diagrammatically represents a fuel element according to a first embodiment of the invention;
FIG. 2 is a top view comparable to FIG. 1 illustrating a second embodiment of the invention;
In the various embodiments described, elements performing comparable functions are denoted using the same numeric references. FIG. 1 diagrammatically shows a top view of a fuel element 10 according to a first embodiment of the invention.
The fuel element 10 is in the form of a single part or a monolithic brick made in a single piece. In this embodiment, the external shape of the fuel element is approximately a parallelepiped. As an illustration of the invention, which is in no way restrictive, the fuel element may have a horizontal section in the form of a square with a side of approximately 30 cm and a height of less than 1 meter.
With this shape, it is possible to put identical fuel elements 10 adjacent to each other or on top of each other inside the nuclear reactor vessel, to form the core of this reactor. Thus, adjacent columns can be formed using a square grid, taking care to allow spaces between the fuel elements in adjacent columns. These spaces facilitate the circulation of a coolant fluid and also the installation of control devices if necessary, as will be described later.