High temperature ceramic nuclear fuel system for light water reactors and lead fast reactors
View Patent ↗An improved, accident tolerant fuel for use in light water and lead fast reactors is described. The fuel includes a ceramic cladding, such as a multi-layered silicon carbide cladding, and fuel pellets formed from U 15 N and from 100 to 10000 ppm of a boron-containing integral fuel burnable absorber, such as UB 2 or ZrB 2 .
1. An accident tolerant fuel combination for light water and lead fast reactors comprising:
a multi-layered ceramic cladding; and
fuel in pellet form positioned within the cladding such that a gap sized to prevent pellet-cladding mechanical interaction and centerline melt during high power excursions is defined between the cladding and the pellet, the fuel comprising U 15 N intermixed with a boron-containing integral fuel burnable absorber selected from the group consisting of UB 2 and ZrB 2 and having a 1310 content at 19% to 80% of the boron.
2. The fuel combination recited in claim 1 wherein the ceramic cladding comprises at least one monolith layer and at least one composite layer.
3. The fuel combination recited in claim 2 wherein the ceramic cladding is made of a SiC monolith layer and a SiC ceramic composite layer.
4. The fuel combination recited in claim 1 wherein the ceramic cladding has a total wall thickness between 0.4 mm and 1.4 mm.
5. The fuel combination recited in claim 1 wherein the U 15 N fuel has a N15 isotope content between 75% and 99.9%.
6. The fuel combination recited in claim 1 wherein the U 15 N fuel has a UN purity greater than 90%.
7. The fuel combination recited in claim 1 wherein the boron-containing integral fuel burnable absorber is UB 2 .
8. The fuel combination recited in claim 1 wherein the boron-containing integral fuel burnable absorber content in the U 15 N pellet is between 100 ppm and 10000 ppm.
9. The fuel combination recited in claim 1 wherein the U 15 N fuel has a density between 80% and 99% of theoretical density.
10. An accident tolerant nuclear fuel combination comprising:
a ceramic cladding comprised of at least a monolith layer and a composite layer;
a plurality of fuel pellets stacked in the cladding such that a gap sized to prevent pellet-cladding mechanical interaction and centerline melt during high power excursions is defined between the cladding and the fuel pellets, the fuel pellets formed from U 15 N mixed with from 100 to 10000 ppm of a boron-containing integral fuel burnable absorber selected from the group consisting of UB 2 and ZrB 2 , having a B10 content at 19% to 80% of the boron.
11. The nuclear fuel combination recited in claim 10 wherein the ceramic cladding is formed from a SiC monolith wrapped in SiC composite fibers.
12. The nuclear fuel combination recited in claim 10 wherein the U 15 N fuel has a N15 isotope content between 75% and 99.9% and a UN purity greater than 90%.
13. The fuel combination recited in claim 1 wherein the gap is between about 0.01 to 0.3 mm.
14. The nuclear fuel combination recited in claim 10 wherein the gap is between about 0.01 to 0.3 mm.