Fuel element of the macrostructured plate type

• US 8,149,984 B2
• Filed: 08/08/2006
• Issued: 04/03/2012
• Est. Priority Date: 08/10/2005
• Status: Expired due to Fees

• 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
• Primary Examiner(s): Palabrica, Rick
• Assistant Examiner(s): LEACH, ERIN MARIE BOYD
• Application Number:
  US11/989,854
• Publication Number:
  US 20090274262A1
• Time in Patent Office: 2,065 Days
• Field of Search: 764/38, 764/32, 764/62, 764/14, 764/16, 764/12, 764/09, 376/438, 376/432, 376/462, 376/414, 376/416, 376/412, 376/409
• 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 first network having a plurality of walls integral with the first plate for forming a plurality of individual cells separated from one another and defined by said walls, and at least one nuclear fuel pellet having opposite sides confined within a corresponding cell such that a circumferential gap is formed between said opposite sides of said pellet and the walls of the cell, with the nuclear fuel pellet extending along an axis aligned in a direction approximately parallel to the walls of the cell;

a second plate disposed in parallel alignment with said first plate on a side of said network opposite to the first plate in order to close the cells;

said second plate is integral with a second network, substantially the same as the first network; and

an axial gap formed between the at least one fuel pellet and the first and second plates.

2. Element according to claim 1, wherein the walls of the networks have the same thickness, taken in a direction parallel to the first and second plates.

3. Element according to claim 1, wherein the first and second networks are manufactured in a unitary manner with the first and second plates, respectively.

4. Element according to claim 1, wherein each closed cell is filled with helium.

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

6. Element according to claim 1, wherein the gaps formed in the cell create a residual volume in such cell, which accounts for at least 40% of the volume of the pellet located in such cell.

7. Element according to claim 1, wherein at least one of the opposite sides of the pellet is curved outwards to minimize comparative stress levels in the plate facing said opposite side of the pellet.

8. Element according to claim 1, wherein the first and second networks are a honeycomb structure of hexagonal cells.

9. Element according to claim 1, wherein the plates and the networks are made from the same refractory material, metal or ceramic.

10. Element according to claim 9, wherein the plates and the networks are composed of a ceramic.

11. Element according to claim 10, wherein said ceramic is SiC.

12. Element according to claim 11, wherein each pellet is cylindrical in geometry.

13. Element according to claim 10, wherein said ceramic is fibrous.

14. Element according to claim 10, further comprising a metallic layer plated on to the walls of each cell.