Fuel assembly for a nuclear boiling water reactor

摘要

The present invention concerns a fuel assembly (4) for a nuclear power boiling water reactor, comprising:
a fuel channel (6) defining a central fuel channel axis (8),
fuel rods (10), each having a central fuel rod axis (12),
at least 3 water channels (14) for non-boiling water, each water channel having a central water channel axis (16) and each water channel having a larger cross-sectional area than the cross-sectional area of (the average) fuel rod (10). The fuel rods (10) comprise a first group of full length fuel rods and a second group of shorter fuel rods. The fuel assembly (4) comprises at least 5 fuel rods which belong to said second group and which are positioned such that the central fuel rod axis (12) of each of these at least 5 fuel rods is closer to the central fuel channel axis (8) than any of the water channel axes (16) of the water channels (14).