Patent Number: 
Section: claims

1. A method of producing a nuclear fuel product, the method comprising:providing a core comprising aluminium and low-enriched uranium, the low-enriched uranium having a proportion of U235 below 20 wt %; andsealing the core in a cladding;the core comprising a first composition including more than 80 wt % of a mixture of UAl3 phase and UAl4 phase, and the mixture having a weight fraction of UAl3 phase higher than or equal to 50%, orthe core comprising a second composition including more than 50 wt % of UAl2 phase,the core having a low-enriched uranium loading higher than 3.0 gU/cm3, the core comprising less than 10 wt % in total of one or several material(s) taken from the list consisting of aluminium phase and aluminium compounds other than UAl2 phase, than UAl3 phase, and than UAl4 phase. 2. The method as recited in claim 1 wherein the cladding comprises one or several of an aluminium alloy, a zirconium alloy, a Ni-based alloy and a stainless steel. 3. The method as recited in claim 2 wherein the aluminium alloy comprises more than 95 wt % of aluminium, the zirconium alloy is Zircaloy-2, Zircaloy-4 or a Zr—Nb alloy, the Ni-based alloy is Alloy 600 and the stainless steel is AISI 304L or AISI 316L. 4. The method as recited in claim 1 wherein the core comprises the second composition. 5. The method as recited in claim 4 wherein the core comprises more than 80 wt % of UAl3 phase. 6. The method as recited in claim 1 wherein the core comprises the second composition preferably more than 80 wt % of UAl2 phase. 7. The method as recited in claim 1 wherein the step of providing the core comprises the substep of melting low-enriched uranium and aluminium in a furnace to form a melt, the proportion of low-enriched uranium in the melt being higher than or equal to 68 wt % and lower than or equal to 82 wt %. 8. The method as recited in claim 7 wherein the proportion of low-enriched uranium in the melt is higher than or equal to 71 wt % and lower than or equal to 75 wt %, wherein the core comprises the first composition. 9. The method as recited in claim 7 wherein the proportion of low-enriched uranium in the melt is higher than or equal to 73 wt % and lower than or equal to 75 wt %, wherein the core comprises more than 80 wt % of UAl3 phase. 10. The method as recited in claim 7 wherein the proportion of low-enriched uranium in the melt is higher than or equal to 75 wt % and lower than or equal to 82 wt % wherein the core comprises the second composition. 11. The method as recited in claim 7 wherein the step of providing the core comprises the substeps of:providing a ingot from the melt;grinding the ingot to produce a powder;compacting the powder to produce a compact; andsintering the compact to obtain the core. 12. The method as recited in claim 11 wherein the step of providing the core comprises:prior to the substep of compacting the powder, the substep of adding aluminium to the powder, the weight proportion of aluminium in the powder being lower than or equal to 10 wt %. 13. The method as recited in claim 1 wherein the step of sealing the core in the cladding comprises the substeps of:enclosing the core in framing elements to obtain a sandwich; androlling the sandwich in order to extend a core length along a rolling direction R by a factor between 1% and 50%. 14. The method as recited in claim 10 wherein the proportion of low-enriched uranium in the melt is higher than or equal to 78 wt % and lower than or equal to 82 wt %. 15. The method as recited in claim 10 wherein the core comprises more than 80 wt % of UAl2 phase. 16. The method as recited in claim 13 wherein the rolling of the sandwich extends the core length by between 5% and 30% and more preferably around 10%. 17. The method as recited in claim 6 wherein the core comprises more than 80% of UAl2 phase. 18. A nuclear fuel product comprising:a core comprising aluminium and low-enriched uranium, the low-enriched uranium having a proportion of U235 below 20 wt %; anda cladding sealing the core;the core comprising a first composition including more than 80 wt % of a mixture of UAl3 phase and UAl4 phase, and the mixture having a weight fraction of UAl3 phase higher than or equal to 50%, orthe core comprising a second composition including more than 50 wt % of UAl2 phase,the core having a low-enriched uranium loading higher than 3.0 gU/cm3 and comprises less than 10 wt % in total of one or several material(s) taken from the list consisting of aluminium phase and aluminium compounds other than UAl2 phase, than UAl3 phase, and than UAl4 phase. 19. The nuclear fuel product as recited in claim 18 wherein the cladding comprises one or several of an aluminium alloy, a zirconium alloy, a Ni-based alloy and a stainless steel. 20. The nuclear fuel product as recited in claim 19 wherein the aluminium alloy comprises more than 95 wt % of aluminium, the zirconium alloy is Zircaloy-2, Zircaloy-4 or a Zr—Nb alloy, the Ni-based alloy includes Alloy 600 and the stainless steel is AISI 304L or AISI 316L. 21. The nuclear fuel product as recited in claim 18 wherein the core comprises the first composition. 22. The nuclear fuel product as recited in claim 21 wherein the core comprises more than 80 wt % of UAl3 phase. 23. The nuclear fuel product as recited in claim 18 wherein the core comprises the second composition. 24. The method as recited in claim 16 wherein the rolling of the sandwich extends the core length by around 10%. 25. The nuclear fuel product as recited in claim 23 wherein the core comprises more than 80 wt % of UAl2 phase.