Patent Number: 051475987
Section: claims

1. A burnable absorber coated nuclear fuel, comprising: (a) a nuclear fuel substrate containing a fissionable material; and  (b) an outer burnable absorber coating applied on an outer surface of said substrate, said outer absorber coating being composed of an inner layer of a boron-bearing material except for erbium boride and an outer layer of an erbium material.  (a) a nuclear fuel substrate containing a fissionable material; and  (b) an outer burnable absorber coating applied on an outer surface of said substrate, said outer absorber coating being composed of an outer layer of a boron-bearing material except for erbium boride and an inner layer of an erbium material. 2. The fuel as recited in claim 1, wherein said boron-bearing material is zirconium diboride. 3. The fuel as recited in claim 1, wherein said erbium material is erbium oxide. 4. The fuel as recited in claim 1, wherein said fissionable material is enriched uranium dioxide. 5. The fuel as recited in claim 1, wherein said erbium material is erbium boride. 6. A burnable absorber coated nuclear fuel, comprising: 7. The fuel as recited in claim 6, wherein said boron-bearing material is zirconium diboride. 8. The fuel as recited in claim 6, wherein said erbium material is erbium oxide. 9. The fuel as recited in claim 6, wherein said erbium material is erbium boride. 10. The fuel as recited in claim 6, wherein said fissionable material is enriched uranium dioxide.