BASKET, METHOD FOR DESIGNING THE SAME, METHOD FOR MANUFACTURING THE SAME, AND BASKET DESIGN PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a highly economical fuel container basket that ensures subcriticality. SOLUTION: A method for designing a fuel container basket, containing a fuel assembly, which keeps cells arrayed so as to be surrounded by first basket materials and second basket materials having macroscopic neutron cross-sections larger than the first basket materials, includes the step of: determining a first model bundle in consideration of a reduction in reactivity due to flammable poison contained in the fuel assembly and a second model bundle in consideration of limited burnup (Step S1); calculating an effective multiplication factor on a normal time by using the first model bundle (Step S3); calculating an effective multiplication factor at the time of an accidental fall at which the distance between fuel rods of the second model bundle is enlarged (Step S4); and changing a cell wall-material array repeatedly until the effective multiplication factors become smaller than a critical limit value and the amount of second basket materials becomes unable to be made smaller (Step S6). COPYRIGHT: (C)2008,JPO&INPIT