| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a fuel assembly that increase the number of fuel rods loaded per fuel assembly and has a complete diagonal line symmetry of fuel rods. <P>SOLUTION: A fuel assembly 1 has regular dodecagonal fuel rod arrays 4 in each of which a fuel rod is arranged at each apex of the regular dodecagon having a length of each side of a. When a direction in a horizontal plane is assumed to be a lateral direction and a direction perpendicular to the lateral direction is assumed to be a longitudinal direction, a plurality of regular dodecagonal fuel rod arrays 4 are arranged at regular intervals in each of the two directions, lateral and longitudinal. In the lateral direction, adjacent two regular dodecagonal fuel rod arrays 4 are arranged in such a manner that two sides of the rod array 4 facing each other are in parallel to each other at intervals of ma (m=0, 1, 2, ... ). In the longitudinal direction, adjacent two regular dodecagonal fuel rod arrays 4 are arranged in such a manner that two sides of the rod array 4 facing each other are in parallel to each other at intervals of na (n=1, 2, 3, ...). <P>COPYRIGHT: (C)2012,JPO&INPIT |
