| 摘要 |
PROBLEM TO BE SOLVED: To provide a set of fuel assemblies for BWR and the like, capable of reducing a local peaking factor of a fuel assembly in which a relatively large number of fuel rods containing burnable poison are arranged, thereby further improving safety of a nuclear reactor.SOLUTION: The set of fuel assemblies which are loaded on a reactor core of BWR at the same time and have the same average enrichment includes a first fuel assembly and a second fuel assembly arranged in square lattice arrangement of 10 or more lines and 10 or more rows. The second fuel assembly has an arrangement in which the number of fuel rods containing burnable poison is larger than the number of fuel rods containing the burnable poison in the first fuel assembly and the fuel rods containing the burnable poison are added only on a virtual diagonal line connecting two facing corner parts, out of four corner parts of the square lattice arrangement, and at positions which are not adjacent to a water rod in the matrix direction, relative to an arrangement of the fuel rods in the first fuel assembly. |
