Fuel Element of the Macrostructured Plate Type

• US 20090274262A1
• Filed: 08/08/2006
• Published: 11/05/2009
• Est. Priority Date: 08/10/2005
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Original Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Inventors: Ravenet, Alain
• Granted Patent: US 8,149,984 B2
• Time in Patent Office: Days
• US Class Current: 376/432
• CPC Class Codes: C04B 2237/122 based on refractory metals
• CPC Class Codes: C04B 2237/36 Non-oxidic
• CPC Class Codes: C04B 2237/365 Silicon carbide
• CPC Class Codes: C04B 2237/385 Carbon or carbon composite
• CPC Class Codes: C04B 2237/76 Forming laminates or joined articles comprising at least one member in the form other than a sheet or disc, e.g. two tubes or a tube and a sheet or disc
• CPC Class Codes: C04B 37/006 consisting of metals or metal salts
• CPC Class Codes: G21C 3/04 Constructional details
• CPC Class Codes: G21C 3/06 Casings; Jackets
• CPC Class Codes: G21C 3/18 Internal spacers or other non-active material within the casing, e.g. compensating for expansion of fuel rods or for compensating excess reactivity interlayers G21C3/20
• CPC Class Codes: G21C 3/36 Assemblies of plate-shaped fuel elements or coaxial tubes
• CPC Class Codes: Y02E 30/30 Nuclear fission reactors

Abstract

A new nuclear fuel element has been developed to be used in particular in fourth generation gaseous heat exchanger reactors working with a fast neutron flow.

With a composite plate structure, the element (1) according to the invention comprises a network of cells (8), more preferably of honeycomb shape, in each of which is placed a nuclear fuel pellet (10). Radial and axial gaps are provided in each cell (8) to compensate for the differential expansion between fissile materials and structural materials inherent in the operation of the plate (1).

Claims

1. Nuclear fuel element comprising a first plate, a network with a plurality of walls integral with the first plate in order to form separate cells, and at least one nuclear fuel pellet extending along an axis, while revolving, between two opposite sides, in which the pellet is located in a cell with a radial gap between its walls and the pellet, the axis of the pellet being approximately parallel to the walls of the cell.

2. Element according to claim 1, in which the walls of the network have the same thickness, taken in a direction parallel to the first plate.

3. Element according to claim 1, in which the network is manufactured in a unitary manner with the first plate.

4. Element according to claim 1, comprising a second plane plate integral with the network, parallel to and opposite the first plate, in order to close the cells.

5. Element according to claim 1, comprising a second plate, comprising a protruding network complementary to the network of the first plate and integral with the network of the first plate, in order to close the cells.

6. Element according to claim 4, comprising a single fuel pellet extending along an axis between two opposite sides located with a radial gap in each closed cell.

7. Element according to claim 6, in which each closed cell is filled with helium.

8. Element according to claim 4, in which the fissile phase of the fuel pellets accounts for more than 20% of the volume of the element.

9. Element according to claim 4, in which the residual volume generated by the gap in each cell, accounts for at least 40% of the volume of the pellet which is located in it.

10. Element according to claim 1, in which each pellet is located in the cell with, in addition, an axial gap.

11. Element according to claim 10, in which at least one of the sides opposite the pellet is curved outwards to minimise comparative stress levels in the facing plate after adjustment of the axial gap.

12. Element according to claim 1, in which the network is a honeycomb structure of hexagonal cells.

13. Element according to claim 1, in which the plates and the network are made from the same refractory material, metal or ceramic.

14. Element according to claim 13, in which the plates and the network are made from a ceramic, in particular SiC, sometimes fibrous.

15. Element according to claim 14, also comprising a metallic layer plated on to the walls of each cell.

16. Element according to claim 1, in which each pellet has the form of a single cylinder revolving about its axis.