title: Difficulties in using 234u/238u ratios to detect enriched or depleted uranium.
abstract: Uranium that is highly enriched in U (HEU) is also often also enriched in U because it too is a lower-mass isotope than U and thus its concentration would be preferentially increased in any mass-sensitive enrichment process. Thus the ratio U/U might be regarded as a surrogate for U/U-the usual measure of enrichment. For this reason it has been suggested that U/U measurements be used to detect contamination by HEU. The purpose of this Note is to point out that, because of alpha-recoil effects, U/U varies widely in natural systems, and for this reason it would not be a dependable indicator of the presence of HEU. The same variations would cause U/U ratios to be doubtful indicators of depleted uranium.
authors.affiliation: Department of Geology, Union College, Schenectady, NY 12308, USA. fleischr@union.edu
authors.forename: Robert L
authors.initials: RL
authors.lastname: Fleischer
mesh_terms: D000465:Algorithms; D016477:Artifacts; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014501:Uranium / Q000032:analysis*
chemical_list: D014501:Uranium