Patent Number: 046684689
Section: claims

1. A fuel pellet for a nuclear fuel assembly fuel rod, comprising: a body having an inner portion disposed within an outer annular portion integral with and surrounding said inner portion, said inner portion being formed from compacted natural uranium oxide powder alone and said outer annular portion being formed of compacted mixtures of enriched uranium oxide and gadolinium oxide powders to provide a fuel pellet that has a lower reactivity than a conventional homogeneously mixed pellet at the beginning of life and a higher reactivity than a conventional homogenously mixed pellet at the end of life.  a body having an inner part and an outer part integral with an surrounding said inner part, said inner part containing enriched nuclear fuel material and said outer part containing only natural nuclear fuel material to provide a fuel pellet that has a lower reactivity than a convnetional homogenously mixed fuel pellet at the beginning of life and a higher reactivity than a conventional homogenously mixed fuel pellet at the end of life. 2. A nuclear fuel pellet for a nuclear fuel assembly fuel rod, comprising: