Fuel assembly containing fuel rods having standardized-length burnable absorber integral with fuel pellets and method of customizing fuel assembly.

摘要

A fuel assembly (10) having a plurality of spaced apart fuel rods (18) includes at least two groups of fuel rods (18A, 18B). In each of the two groups (18A, 18B), each fuel rod contains first and second pluralities of nonpoisoned and poisoned fuel pellets (34A, 34B). The plurality of poisoned fuel pellets (34B) in each fuel rod of the first group (18A) is of a first standard length, whereas the plurality of poisoned fuel pellets (34B) in each fuel rod of the second group (18B) is of a second standard length different than the first standard length. The first and second standard lengths of the pluralities of poisoned fuel pellets (34B) of the two groups of fuel rods (18A, 18B) provide an overall average length of burnable poison across the fuel assembly (10). The fuel assembly (10) also contains a third group of fuel rods (18C) only containing a plurality of nonpoisoned fuel pellets (34A).