Open AccessCriticality Experiments with Subcritical Clusters of 2.35 Wt% and 4.31 Wt% 235U Enriched U02 Rods in Water with Uranium or Lead Reflecting Walls Undermoderated Water-to-Fuel Volume Ratio of 1.6
Author(s) -
S.R. Bierman,
B.M. Durst,
E.D. Clayton
Publication year - 1981
Language(s) - English
Resource type - Reports
DOI - 10.2172/1083949
Subject(s) - uranium , rod , enriched uranium , criticality , nuclear fuel , volume (thermodynamics) , depleted uranium , actinide , materials science , lead (geology) , spent nuclear fuel , surface area to volume ratio , nuclear engineering , chemistry , nuclear physics , geology , nuclear chemistry , physics , metallurgy , thermodynamics , medicine , alternative medicine , pathology , geomorphology , engineering , paleontology
A series of criticality experiments with undermoderated (1.6 water-to-fuel volume ratio) 2.35 wt% and 4.31 wt% {sup 235}U enriched UO{sub 2} rods in water were performed to provide data on the reactivity effects of lead and depleted uranium reflecting walls. This data furnishes well defined benchmarks for use in validating calculational techniques employed in analyzing fuel shipping and storage systems having lead or uranium biological shields. For each fuel enrichment, the critical separation between three subcritical fuel clusters was observed to increase as either 77mm thick depleted uranium or 102mm thick lead reflecting walls were moved towards the fuel. A maximum critical separation was observed for both the lead and the depleted uranium reflecting walls with a water gap between the fuel clusters and the reflecting walls. For both fuel enrichments, this optimum water gap was about 25mm for the depleted uranium walls and about lOmm for the lead walls