| 摘要 |
A nuclear reactor of boiling water type has a reactor core including a plurality of vertical fuel assemblies (30, 30a) of substantially square cross section arranged in a lattice, with each fuel assembly included in two rows of fuel assemblies, perpendicular to each other and separated by intermediate water gaps (27a, 27b). Each fuel assembly comprises two vertical perpendicular sides, each side facing a water gap which has a larger width than a water gap toward which the opposite two vertical perpendicular sides face. After an operating cycle for the reactor of at least two years, the majority of the fuel assemblies used during the completed operating cycle, which are located in an edge zone (25) furthest out in the core, are turned 180 degrees around the vertical center line of the respective fuel assembly, and the turned fuel assemblies are used for a following operating cycle of the reactor. |
