title: Measurement of the tritium concentration in the fractionated distillate from environmental water samples.
abstract: Standard procedures for the measurement of tritium in water samples often require distillation of an appropriate sample aliquot. This distillation process may result in a fractionation of tritiated water and regular light water due to the vapor pressure isotope effect, introducing either a bias or an additional contribution to the total tritium measurement uncertainty. The current study investigates the relative change in vapor pressure isotope effect in the course of the distillation process, distinguishing it from and extending previously published measurements. The separation factor as a quantitative measure of the vapor pressure isotope effect is found to assume values of 1.04 ± 0.036, 1.05 ± 0.026, and 1.07 ± 0.038, depending on the vigor of the boiling process during distillation of the sample. A lower heat setting in the experimental setup, and therefore a less vigorous boiling process, results in a larger value for the separation factor. For a tritium measurement in water samples where the first 5 mL are discarded, the tritium concentration could be underestimated by 4-7%.
authors.affiliation: Environmental and Radiological Health Sciences, Colorado State University, 1618 Campus Delivery, Fort Collins, CO 80523, USA. Electronic address: Robert.Atkinson@wpafb.af.mil.
authors.forename: Robert
authors.initials: R
authors.lastname: Atkinson
authors.affiliation: Savannah River National Laboratory, Savannah River Nuclear Solutions, Aiken, SC 29808, USA. Electronic address: Teresa.eddy@srnl.doe.gov.
authors.forename: Teresa
authors.initials: T
authors.lastname: Eddy
authors.affiliation: Savannah River National Laboratory, Savannah River Nuclear Solutions, Aiken, SC 29808, USA. Electronic address: Wendy.Kuhne@srnl.doe.gov.
authors.forename: Wendy
authors.initials: W
authors.lastname: Kuhne
authors.affiliation: Savannah River National Laboratory, Savannah River Nuclear Solutions, Aiken, SC 29808, USA. Electronic address: Tim.jannik@srnl.doe.gov.
authors.forename: Tim
authors.initials: T
authors.lastname: Jannik
authors.affiliation: Environmental and Radiological Health Sciences, Colorado State University, 1618 Campus Delivery, Fort Collins, CO 80523, USA. Electronic address: Alexander.brandl@colostate.edu.
authors.forename: Alexander
authors.initials: A
authors.lastname: Brandl
mesh_terms: D011834:Radiation Monitoring; D012588:Scintillation Counting; D014316:Tritium / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D014316:Tritium
keywords: Surface water samples; Tritium analysis; Vapor pressure isotope effect