摘要 |
Among fuel rods 13, 14, 15, 16, 17, 18, 19 constituting a fuel assembly, Gd compound oxide is added to low Gd containing fuel rods 16, 17, 18 containing uranium dioxide of which enrichment exceeds 5 wt%. The Gd compound oxide is oxide of gadolinium and rare earth element "A" except for gadolinium and is expressed as a chemical formula A 1-x Gd x O 2-0.5x or a chemical formula A 1-x Gd x O 1.5 . As the rare earth element "A", cerium Ce, lanthanum La or erbium Er can be used. |