Critical Parameters of Complex Geometries of Intersecting Cylinders Containing Uranyl Nitrate Solution

摘要

About three dozen previously unreported critical configurations are presented for very complex geometries filled with high concentration enriched uranyl nitrate solution. These geometries resemble a tall, thin Central Column (or trunk of a 'tree') having long, thin arms (or 'branches') extending up to four directions off the column. Arms are equally spaced from one another in vertical planes, and that spacing ranges from arms in contact to quite wide spacings. Both the Central Column and the many different arms are critically safe by themselves with each, alone, is filled with fissile solution; but, in combination, criticality occurs due to the interactions between arms and the column. Such neutronic interactions formed the principal focus of this study. While these results are fresh to the nuclear criticality safety industry and to those seeking novel experiments against which to validate computer codes, the experiments, themselves, are not recent. Over 100 experiments were performed at the Rocky Flats Critical Mass Laboratory between September, 1967, and February of the following year.